# COIN-GPS: Indoor Localization from Direct GPS Receiving

Save this PDF as:

Size: px
Start display at page:

## Transcription

5 computes the correlation as in Equation : XL R[m] = x[n]ca[(n + m) L ], apple m apple L () n= where x[n], CA[(n+m) L ], and R[m] denote the L-length signals, the C/A code which is shifted m places modulo L, and the m th correlation, respectively A correlation plot (code phase vs correlation) is obtained by computing all R[m]s The unique highest peak in the plot signifies the presence of the satellite, whereas a flat line means the satellite is not acquired The displacement of the peak in the plot is the code phase which gives us the sub-ms part of the propagation delay Sat Sat 3 Receiver Local C/A codes ms * * Demodulated signals Code Phase Figure 3: Simplified standard satellite acquisition One caveat is that the above algorithm does not deal with Doppler shifts which must be taken into account during acquisition Taking Doppler e ect into account is done simply by replicating the entire process, each time using a di erent frequency within the range of ±4 khz of the carrier frequency With this modification, the search space becomes a D state space consisting of all possible code phases and Doppler shifts In our implementation, we use 5 frequency bins and process them in parallel to speed up the search 5 Frequency-Domain Search Most commercial receivers use the above linear search algorithm for its simplicity However, with computing correlation repeatedly being slow, we use a faster method in COIN-GPS, in which, correlations are computed with the help of FFT as shown in Equation This is possible since Equation resembles a convolution operation which is multiplication in the frequency domain [38] shows that the FFT search is x faster than the linear search algorithm R[m] = x[n] CA[ n] = F (F (x[n]) F(CA[n]) ) () In order to find the unique peak in R[m], apple m apple L, the ratio of the maximum and the average (or, the second highest peak) of R[m] is taken, and if it is above a threshold, the satellite is considered acquired Because of the properties of the C/A codes (which are 3-length Gold codes), ideally, only a non-delayed exact replica of a C/A code will produce a normalized correlation value of (after dividing by the length 3) For any other delays or any other satellite s C/A code, the autocorrelation is close to zero, or more precisely one of these three values: /3, 63/3, or 65/3 Hence, a R[m] close to and a > indicate that we have acquired the satellite 5 Robust Acquisition 5 Integrating Correlations In the presence of noise, the idealistic nature of R[m] does not hold, and detecting the right peak becomes non-trivial In order to understand the e ect of noise on peak R[m], we perform an experiment, where we distort a GPS packet, obtained from a commercial GPS receiver, by artificially adding Gaussian noise (AWGN) and correlate it with a noise free C/A code Figure 4 shows that as we vary the SNR from +5 db to 6 db, R[m] deviates from its ideal value of, and the peak ratio gets close to, which means that the highest peak becomes comparable to noise Therefore, in indoor environments where SNR is below 3 db, we won t be able to acquire any satellite with a regular GPS Peak R[m] SNR Peak Ratio (ρ) SNR Figure 4: E ect of SNR on correlation peak With dbi directional gain, a directional antenna helps reduce a great deal of noise However, to complement its capability, we perform additional signal processing during acquisition To further reduce noise, we use a non-coherent integrator to element-wise add correlations from consecutive ms signal chunks Assuming R (i) [m] to be the correlation from the i th chunk of ms signals, the integrated correlations are obtained from Equation 3: R [m] = KX R (i) [m] (3) i= The e ect of this integration is illustrated with an example in Figure 5 The first plot having K = uses only ms of signals to produce the correlation plot The seemingly highest peak in this plot is labeled as the wrong peak, which becomes evident when we integrate correlations obtained from, 4, and 8 ms of signals in the next three plots The reason the peak is clearer in the later plots is that the highest peak remains at the same position while the noise varies The more we integrate, the closer we get to the expected values and the more the variance is reduced Correlation Correlation 4 x x Wrong Peak Code Phase Code Phase 45 x 6 4 K = K = Correlation x 7 K = 4 K = 8 Actual 5 Peak Correlation Code Phase Code Phase Figure 5: Longer integration produces a better peak Analysis: Assuming E[R] and E[N] to be the expected values of correlation power and squared noise, respectively, the expected

8 section, we use the superscript (i, k) to denote the k th satellite in i th chunk, where apple i apple M and apple k apple K i Before we derive an expression for the pseudo-range error z (i,k), we make the following assumptions: The (x, y, z) coordinates are the same in all chunks Each chunk has a bias b i and a coarse time error tc i Total number of satellites P M j= K j M + 3 Generalizing Equation 8 we obtain: z (i,k) = e (i,k) p xyz + bi + (i,k) tc i () where Considering all K i satellites in i th chunk: H (i) = 64 z (i) = H (i) p (i) (3) 3 e (i,) (i,) 75 e (i,k i) (i,k i) (4) Extending the state variable p by including all (M + 3) variables, for p = [x, y, z, b, tc,b M, tc M ] T we rewrite the above equation as: 3 e (i,) (i,) H (i) = (5) e (i,k i) (i,k i) Stacking up all H (i),apple i apple M, we get the observation matrix H for indoor navigation: e (,) (,) 3 e (,K ) (,K ) H = (6) e (M,) (M,) e (M,K M) (M,K M) Finally, we obtain p by using the standard least squares solution as done in Equation 7 SYSTEM IMPLEMENTATION So far we have provided a generic description of how an indoor GPS could be built This section describes the specific implementation of COIN-GPS 7 Front End Hardware The front-end of COIN-GPS consists primarily of three components: a high-gain directional antenna, the direction controller, and a GPS signal logger, which are connected to a PC as shown in Figure 7 Antenna Design In order to have a reasonable gain and also a reasonable size of the antenna, we built an antenna with a 4 4 array of patches that has the dimensions of inches and a thickness of < 5 inch The antenna has a directional gain of 3 dbi, a half-power beam width of 35, and a broad-side angle of 5 Figure (a) shows the simulated gain of the antenna in 3D The antenna is directional, Figure : The antenna and the signal logger are connected to a PC which means it receives signals along its Z-axis, and the receiving direction is controllable Figure (b) shows that its receiving frequency is 575 GHz, matching the GPS signal frequency Z (a) Antenna Beam θ Y Φ X (b) Return Loss Figure : Antenna Beam and Return Loss (a) Antenna Front (b) Antenna Back Figure : Front and Back of the Antenna The antenna is composed of two two-layer boards (boards with two copper layers and one substrate layer) that are physically connected to each other by plastic screws The substrate used for each two-layer board is RT/Duroid 588 Its low dielectric constant ( r = ) and low loss tangent (tan = 9) is the most suitable substrate for producing maximal gain for a given patch antenna topology One of the boards (Board A) consists of a ground layer that is filled with 6 coupling slots (one for each patch antenna) and a corporate feeding network The other board (Board B) has an analogous ground layer, filled with 6 coupling slots, and a layer with 6 patches The size of each patch is 5 5 inches 7 Steering the Antenna In COIN-GPS, we attempt to receive GPS signals from a total of nine main beam directions with respect to the X-Z and Y-Z el-

10 quantify this using our empirical data Figure 3 shows the number of satellites acquired by both COIN-GPS and the Garmin setup, as we vary the amount of signals over which we integrate the correlation We observe that the number of acquired satellites increases in both cases, however, COIN-GPS acquires 3 satellites (on average) when we integrate 5 or more correlation terms (shaded region in the figure) With the Garmin antenna, the average number hardly ever reaches, even when we integrate over ms The state-ofthe-art CO-GPS (or any instant GPS), which uses ms signals, does not acquire even a single satellite Thus, this result justifies the use of our high-gain directional antenna as well as our robust acquisition technique, which lets COIN-GPS acquire enough satellites to obtain a location fix in an indoor environment Using only the robust acquisition algorithm alone would increase the number of acquired satellites from zero to two, but that wouldn t be su - cient Using only the high-gain antenna alone would increase the number of acquired satellites from zero to one, which would also not be su cient to estimate the location Acquired Satellites 4 3 Garmin COIN-GPS Signal Length (ms) CO-GPS Figure 3: Signal length and acquired satellites The underlying reason that using a longer signal length helps is understood when we plot the peak ratios of a correlation plot for di erent amount of signals Figure 4(a) shows that as we increase the amount of signals over which we integrate the correlation, the ratio between the highest two peaks (peak ratio) increases However, after 5 ms, the increase is not significant and settles at around 7 Therefore, this number is used as a threshold in determining whether or not a satellite is acquired Peak Ratio Signal Length (ms) (a) Peak ratio Code Phase Error Signal Length (ms) (b) Code phase error Figure 4: Peak ratio and code phase error Another important thing to notice is the errors in estimated code phases as we consider longer signals This is because, ultimately, it is the code phase estimation error that determines the location estimation error in an instant GPS receiver by and large Figure 4(b) shows that the relative code phase error diminishes as more and more correlation terms are integrated and becomes less than 5% when 7 or more correlation terms are integrated Hence, this plot provides a guide in selecting a value of signal length to minimize the expected location estimation error In COIN-GPS, we use 5 ms as our default integration length 83 Indoor Satellite Distribution COIN-GPS requires acquisition of at least 3 satellites to obtain a location fix In this experiment, we empirically determine the distribution of the number of acquired satellites (from a single direction in COIN-GPS) for both COIN-GPS and CO-GPS (using a Garmin front-end) Figure 5 shows that CO-GPS acquires or more satellites with only % probability, and never acquires 3 or more satellites and never obtains a location fix On the other hand, COIN-GPS acquires at least 3 satellites 6% of the time, which means COIN-GPS is capable of obtaining a location fix in these cases Compared to the state-of-the-art CO-GPS s % success rate, this is a significant improvement P(X) Garmin/COgps COIN GPS X: X or more satellites are acquired Figure 5: Distribution of acquired satellites 84 Location Estimation Algorithm Evaluation 84 Combining Directional Acquisitions COIN-GPS combines acquired satellites from up to nine directions to address the inadequate satellite problem We empirically determine the number of directional acquisitions that are combined in COIN-GPS whenever there has been a successful location fix Figure 6 shows the CDF of the number of directions combined We see that, amongst all successful fixes, 63% use only one direction, 8% use, and 3 directions are required for the rest P(Fix) Number of Directions Combined Figure 6: Distribution of location fixes 84 Bias and Coarse Time Error Terms In COIN-GPS, for M independent directional acquisitions, we assume there are M unknown bias terms and M unknown coarse time error terms In this experiment, our goal is to see how di erent the biases and the coarse time o sets are and thus justify the assumption Figure 7 shows all-pair biases and coarse time o sets obtained after solving the navigational equations Each point (b i, b j ) in Figure 7(a) represents two bias terms b i and b j from the same set of equations Similarly, Figure 7(b) shows the coarse time o sets in pairs If all M biases (or all M coarse time errors) were the same, the plot would be a straight line with a slope of However, we see that the biases are highly scattered and most of the coarse time o sets are o the diagonal line Making all M biases and all M coarse term o sets the same would result in estimated pseudo-range errors of 4 m and 5 m, respectively Hence, by considering them

11 b j 4 4 b i (a) bias ( 5 m) tc j tc i (b) coarse time (ms) Figure 7: Bias and Coarse Time as M independent unknown variables, COIN-GPS has eliminated such large errors 85 Location Estimation Case Studies We deploy COIN-GPS in five real-world indoor environments and summarize the results in Figures 8 In each figure, a pair of downward arrows on the map show the true (green) and estimated (red) locations, and the dotted line shows the displacement The table on the right compares COIN-GPS with the baseline, and the plot shows the localization errors B D A A B C 5 System Locations Fixes Garmin None COIN-GPS Location Estimation Error 7 Figure 8: Starbucks A B Avg System Locations Fixes Garmin 4 None COIN-GPS 4 4 Location Estimation Error 77 6 Figure 9: Home Depot A B C D Avg COIN-GPS performs its best at Starbucks (Figure 8) and Home Depot (Figure 9), showing a % success rate in obtaining a location fix These places are suitable for COIN-GPS as there is a large window at the front of Starbucks, and there are several skylights in Home Depot which are made of glass and framed with steel In these locations, even some of the directional acquisitions (acquired satellites from a single direction with our antenna) had enough satellites to get a location fix On average, COIN-GPS acquires 35 satellites per direction in both locations, and obtains location fixes with 44 5 m errors With such errors, we can distinguish between a customer at Starbucks waiting in the line versus a customer sitting in the deep back of the store We can also identify the section a customer is in Home Depot (eg cleaning, plumbing, moulding, or lumber) The baseline Garmin setup, on the other hand, sees < satellite on average, and never gets a location fix E D G H C F B I A System Locations Fixes Garmin 6 None COIN-GPS Location Estimation Error A B C D E F G H I Avg Figure : Bellevue Square Mall (two storied) The Bellevue Square Mall (Figure ) is a large, multi-storied shopping mall We conduct our experiment on its first and the second floors where a large walking area on the first floor shares the same roof with the top floor Starting from A on the second floor, we take measurements from 8 spots on the second floor, 8 on the first floor, and stop at I We get 6 successful fixes (A F) on the second floor, and 3 on the first (G I) with average errors of m and 77 m, respectively We get higher errors on the second floor (eg A) than the first (eg I) as sometimes the signals are reflected by the lower floor before they reach the top floor The Garmin receiver, on the other hand, hardly acquires a satellite at any spot and hence does not get any location fix B C A 4 Figure : Fred Meyer System Locations Fixes Garmin 5 None COIN-GPS 5 3 Location Estimation Error A B C Avg The two most di cult cases for COIN-GPS have been the Fred Meyer (Figure ) and the Costco (Figure ) These buildings are somewhat sealed, having a ceiling made of concrete and a thick layer of steel framework, and they have no skylights In these locations, we always had to combine multiple directions to obtain the required number of satellites As this combination of directional acquisitions depends on the correct estimation of bias and coarse time errors, in general, their accuracy is lower Out of a total of 9 spots inside these two buildings, COIN-GPS obtains 5 successful location fixes with an aggregate average error of 76 m The received signals inside these buildings are so weak that COIN-GPS acquires 3 or more satellites in only about 3% of the directional acquisitions The Garmin device acquires absolutely no satellite at all in these locations Although COIN-GPS has its largest error

12 A B 6 4 Figure : Costco System Locations Fixes Garmin 4 None COIN-GPS 4 Location Estimation Error A B Avg in these scenarios, still the result is remarkable as it is capable of getting a location fix when the state-of-the-art does not even see a satellite Min Median Mean P9 Max Table : Summary of Localization Errors Table shows the overall min, median, mean, 9th percentile, and max errors in our study While a mean location estimation error of 73 m is comparable to the errors of an outdoor GPS, such an error is not suitable for most indoor location sensing applications in general COIN-GPS with such an error may not be suitable to provide eg aisle-level accuracy within a supermarket, but can provide a zone-level accuracy But this error is not a fundamental limit, rather a limitation of our implementation There are scopes to improve the current solution, and the right way to proceed towards that is to understand the sources of errors One source of such errors is multipaths We notice that most large errors occur when there are more than one received directions It is possible that reflected signals from the same satellites caused pseudo-range errors This can be eliminated to some extent by steering the directional antenna towards the predicted location of the satellites instead of steering the antenna towards a fixed set of directions as done in this paper As each satellite orbits around the Earth in a somewhat regular pattern, it is possible to predict the direction of a satellite at a given time of the day We did not apply this technique in COIN-GPS in order to keep our solution simple This requires further investigation and we keep this as our future work Besides multipaths, the other possible causes of location estimation errors are the indoor SNR and the errors during combining the directional acquisitions Due to the lack of proper instrumentation, we could not capture the actual SNR of the GPS signals during our field study However, the peak-ratios of the correlation plots can be used as an alternative to the SNR The larger the ratio, the better is SNR Table 3 shows the number of acquired satellites, the number of directions combined to get a location fix, the mean peakratios in the correlation plots, and the location estimation errors for each of the spots For each location, we order the spots by the location estimation errors We observe that the largest of the errors in each location happens whenever there is a need to combine two or more directional acquisitions and the total number of satellites is large This can be somewhat compensated for if we consider the quality of acquired satellites when combining the directional acquisitions The mean peak-ratio of a single directional acquisition can Location Spot Satellites Directions Peak Ratio Peak Ratio Error count count mean max meters Starbucks A B Home Depot D B A C Square Mall G I F E C B D H A Fred Meyer C B A Costco B A Table 3: Number of acquired satellites, number of directions combined to estimate the location, mean and max peak-ratios, and the location estimation error for each location are shown For each location, spots are sorted by the location estimation errors be used as an indication of the quality of the acquired satellites 9 DISCUSSION Steering the Antenna Electronically: Instead of using a programmable robot to steer the antenna physically, a more convenient alternative is to steer the beam electronically We have implemented a prototype of such an electronically steerable antenna and tested its capability at a limited scale As it was not used in our deployment experiments, we do not include this design while describing our implementation Instead, we discuss it here for interested readers Figure 3: Electronically controllable antenna In Figure 3, the corporate feeding network is designed to provide excitation in-phase to all 6 patches When this in-phase excitation occurs, the radiation pattern is broadside with maximal gain at around To enhance the reception of signals at di erent angles away from broadside without physically maneuvering the antenna, 6 voltage-controlled phase shifters (one for each antenna) are integrated to the network The phase shifters o er 36 of phase delay controlled by a voltage that ranges from 3 V By changing these control voltages, the phases of the individual patches are shifted, and, in turn, the main beam of the radiation pattern is tilted The voltage-controlled phase shifters are controlled by an externally-connected PCB that has a programmable SoC, and is powered through a USB cable connected to a laptop By chang-

14 MobiSys, pages 4 54, New York, NY, USA, ACM [3] G Dedes and A G Dempster Indoor gps positioning In Proceedings of the IEEE Semiannual Vehicular Technology Conference, 5 [4] T Denidni and Q Rao Design of single layer broadband slot antennas Electronics Letters, 4(8):46 463, 4 [5] A Goswami, L E Ortiz, and S R Das Wigem: a learning-based approach for indoor localization In Proceedings of the Seventh COnference on emerging Networking EXperiments and Technologies, page 3 ACM, [6] Y Gu, A Lo, and I Niemegeers A survey of indoor positioning systems for wireless personal networks Communications Surveys & Tutorials, IEEE, ():3 3, 9 [7] A Haeberlen, E Flannery, A M Ladd, A Rudys, D S Wallach, and L E Kavraki Practical robust localization over large-scale 8 wireless networks In Proceedings of the th annual international conference on Mobile computing and networking, pages 7 84 ACM, 4 [8] X Jiang, C-J M Liang, K Chen, B Zhang, J Hsu, J Liu, B Cao, and F Zhao Design and evaluation of a wireless magnetic-based proximity detection platform for indoor applications In Proceedings of the th International Conference on Information Processing in Sensor Networks, IPSN, pages 3, New York, NY, USA, ACM [9] M B Kjærgaard, H Blunck, T Godsk, T Toftkjær, D L Christensen, and K Grønbæk Indoor positioning using gps revisited In Pervasive Computing, pages Springer, [] R Li, G DeJean, M M Tentzeris, and J Laskar Development and analysis of a folded shorted-patch antenna with reduced size Antennas and Propagation, IEEE Transactions on, 5():555 56, 4 [] H Liu, H Darabi, P Banerjee, and J Liu Survey of wireless indoor positioning techniques and systems Systems, Man, and Cybernetics, Part C: Applications and Reviews, IEEE Transactions on, 37(6):67 8, 7 [] J Liu, B Priyantha, T Hart, H S Ramos, A A Loureiro, and Q Wang Energy e cient gps sensing with cloud o oading In SenSys, pages 85 98, [3] D López de Ipiña, P R S Mendonça, and A Hopper Trip: A low-cost vision-based location system for ubiquitous computing Personal Ubiquitous Comput, 6(3):6 9, Jan [4] P Misra and P Enge Global positioning system: Signals, measurements and [5] M Montemerlo, S Thrun, D Koller, and B Wegbreit FastSLAM: A factored solution to the simultaneous localization and mapping problem In AAAI/IAAI, pages , [6] L M Ni, Y Liu, Y C Lau, and A P Patil Landmarc: indoor location sensing using active rfid Wireless networks, (6):7 7, 4 [7] D M Pozar Microstrip antennas Proceedings of the IEEE, 8():79 9, 99 [8] N B Priyantha, A Chakraborty, and H Balakrishnan The cricket location-support system In Proceedings of the 6th annual international conference on Mobile computing and networking, pages 3 43 ACM, [9] A Rai, K K Chintalapudi, V N Padmanabhan, and R Sen Zee: Zero-e ort crowdsourcing for indoor localization In Proceedings of the 8th annual international conference on Mobile computing and networking, pages ACM, [3] S K Rao Parametric design and analysis of multiple-beam reflector antennas for satellite communications Antennas and Propagation Magazine, IEEE, 45(4):6 34, 3 [3] M Redzic, C Brennan, and N E O Connor Dual-sensor fusion for indoor user localisation In Proceedings of the 9th ACM International Conference on Multimedia, MM, pages 4, New York, NY, USA, ACM [3] J Shotton, T Sharp, A Kipman, A Fitzgibbon, M Finocchio, A Blake, M Cook, and R Moore Real-time human pose recognition in parts from single depth images Communications of the ACM, 56():6 4, 3 [33] S P Tarzia, P A Dinda, R P Dick, and G Memik Indoor localization without infrastructure using the acoustic background spectrum In Proceedings of the 9th international conference on Mobile systems, applications, and services, pages ACM, [34] G Thiele Analysis of yagi-uda-type antennas Antennas and Propagation, IEEE Transactions on, 7():4 3, 969 [35] F van Diggelen Indoor gps theory & implementation In Position Location and Navigation Symposium, IEEE, pages 4 47 IEEE, [36] F van Diggelen and C Abraham Indoor gps technology CTIA Wireless-Agenda, Dallas, [37] F S T Van Diggelen A-gps: Assisted GPS, GNSS, and SBAS Artech House, 9 [38] D Van Nee and A Coenen New fast gps code-acquisition technique using t Electronics Letters, 7():58 6, 99 [39] H Wang, S Sen, A Elgohary, M Farid, M Youssef, and R R Choudhury No need to war-drive: Unsupervised indoor localization In Proceedings of the th international conference on Mobile systems, applications, and services, pages 97 ACM, [4] O Woodman and R Harle Pedestrian localisation for indoor environments In Proceedings of the th international conference on Ubiquitous computing, pages 4 3 ACM, 8 [4] O Woodman and R Harle Rf-based initialisation for inertial pedestrian tracking In Pervasive Computing, pages Springer, 9 [4] C Yang, T Nguyen, E Blasch, and M Miller Post-correlation semi-coherent integration for high-dynamic and weak gps signal acquisition In Position, Location and Navigation Symposium, 8 IEEE/ION, pages IEEE, 8 [43] M Youssef and A Agrawala The horus wlan location determination system In Proceedings of the 3rd international conference on Mobile systems, applications, and services, pages 5 8 ACM, 5 [44] M Youssef, M A Yosef, and M El-Derini Gac: Energy-e cient hybrid gps-accelerometer-compass gsm localization In Global Telecommunications Conference (GLOBECOM ), IEEE, pages 5 IEEE,

### EE4367 Telecom. Switching & Transmission. Prof. Murat Torlak

Path Loss Radio Wave Propagation The wireless radio channel puts fundamental limitations to the performance of wireless communications systems Radio channels are extremely random, and are not easily analyzed

### is the power reference: Specifically, power in db is represented by the following equation, where P0 P db = 10 log 10

RF Basics - Part 1 This is the first article in the multi-part series on RF Basics. We start the series by reviewing some basic RF concepts: Decibels (db), Antenna Gain, Free-space RF Propagation, RF Attenuation,

### Antennas & Propagation. CS 6710 Spring 2010 Rajmohan Rajaraman

Antennas & Propagation CS 6710 Spring 2010 Rajmohan Rajaraman Introduction An antenna is an electrical conductor or system of conductors o Transmission - radiates electromagnetic energy into space o Reception

### Avaya WLAN 9100 External Antennas for use with the WAO-9122 Access Point

Avaya WLAN 9100 External Antennas for use with the WAO-9122 Access Point Overview To optimize the overall performance of a WLAN in an outdoor deployment it is important to understand how to maximize coverage

### Antenna Deployment Technical Brief

ProCurve Networking Antenna Deployment Technical Brief Introduction... 2 Antenna types... 2 Omni directional antennas... 2 Directional antennas... 2 Diversity antennas... 3 High gain directional antennas...

### Antenna Properties and their impact on Wireless System Performance. Dr. Steven R. Best. Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013

Antenna Properties and their impact on Wireless System Performance Dr. Steven R. Best Cushcraft Corporation 48 Perimeter Road Manchester, NH 03013 Phone (603) 627-7877 FAX: (603) 627-1764 Email: sbest@cushcraft.com

### Maximizing Throughput and Coverage for Wi Fi and Cellular

Maximizing Throughput and Coverage for Wi Fi and Cellular A White Paper Prepared by Sebastian Rowson, Ph.D. Chief Scientist, Ethertronics, Inc. www.ethertronics.com March 2012 Introduction Ask consumers

### Omni Antenna vs. Directional Antenna

Omni Antenna vs. Directional Antenna Document ID: 82068 Contents Introduction Prerequisites Requirements Components Used Conventions Basic Definitions and Antenna Concepts Indoor Effects Omni Antenna Pros

### General GPS Antenna Information APPLICATION NOTE

General GPS Antenna Information APPLICATION NOTE General GPS Antenna Information Global Positioning System and Precise Time & Frequency The Global Positioning System (GPS) is a worldwide radio-navigation

### Email: tjohn@mail.nplindia.ernet.in

USE OF VIRTUAL INSTRUMENTS IN RADIO AND ATMOSPHERIC EXPERIMENTS P.N. VIJAYAKUMAR, THOMAS JOHN AND S.C. GARG RADIO AND ATMOSPHERIC SCIENCE DIVISION, NATIONAL PHYSICAL LABORATORY, NEW DELHI 110012, INDIA

### Attenuation (amplitude of the wave loses strength thereby the signal power) Refraction Reflection Shadowing Scattering Diffraction

Wireless Physical Layer Q1. Is it possible to transmit a digital signal, e.g., coded as square wave as used inside a computer, using radio transmission without any loss? Why? It is not possible to transmit

### Introduction. Antennas and Propagation. Types of Antennas. Radiation Patterns. Antenna Gain. Antenna Gain

Introduction Antennas and Propagation Chapter 5 An antenna is an electrical conductor or system of conductors Transmission - radiates electromagnetic energy into space Reception - collects electromagnetic

### E190Q Lecture 5 Autonomous Robot Navigation

E190Q Lecture 5 Autonomous Robot Navigation Instructor: Chris Clark Semester: Spring 2014 1 Figures courtesy of Siegwart & Nourbakhsh Control Structures Planning Based Control Prior Knowledge Operator

### Antennas and Propagation. Chapter 3: Antenna Parameters

Antennas and Propagation : Antenna Parameters Introduction Purpose Introduce standard terms and definitions for antennas Need a common language to specify performance Two types of parameters 1. Radiation

### MSAN-001 X-Band Microwave Motion Sensor Module Application Note

1. Introduction HB Series of microwave motion sensor module are X-Band Mono-static DRO Doppler transceiver front-end module. These modules are designed for movement detection, like intruder alarms, occupancy

### Impedance 50 (75 connectors via adapters)

VECTOR NETWORK ANALYZER PLANAR TR1300/1 DATA SHEET Frequency range: 300 khz to 1.3 GHz Measured parameters: S11, S21 Dynamic range of transmission measurement magnitude: 130 db Measurement time per point:

### Universal Form-factor. Wi Fi Troubleshooting Made Easy

AirMedic USB AirMedic USB is a powerful, easy-touse and affordable spectrum analysis tool that brings Wi-Fi troubleshooting to entry-level users. Built upon AirMagnet expertise in Wi-Fi troubleshooting,

### RECOMMENDATION ITU-R F.1113. (Question ITU-R 157/9) b) that systems using this mode of propagation are already in service for burst data transmission,

Rec. ITU-R F.1113 1 RECOMMENDATION ITU-R F.1113 RADIO SYSTEMS EMPLOYING METEOR-BURST PROPAGATION (Question ITU-R 157/9) (1994) Rec. ITU-R F.1113 The ITU Radiocommunication Assembly, considering a) that

### Enhancing the SNR of the Fiber Optic Rotation Sensor using the LMS Algorithm

1 Enhancing the SNR of the Fiber Optic Rotation Sensor using the LMS Algorithm Hani Mehrpouyan, Student Member, IEEE, Department of Electrical and Computer Engineering Queen s University, Kingston, Ontario,

### Digital Signal Processing For Radar Applications

Digital Signal Processing For Radar Applications Altera Corporation Radar: RAdio Detection And Ranging Need a directional radio beam Measure time between transmit pulse and receive pulse Find Distance:

### Non-Data Aided Carrier Offset Compensation for SDR Implementation

Non-Data Aided Carrier Offset Compensation for SDR Implementation Anders Riis Jensen 1, Niels Terp Kjeldgaard Jørgensen 1 Kim Laugesen 1, Yannick Le Moullec 1,2 1 Department of Electronic Systems, 2 Center

### ProCurve Networking Antenna Deployment

ProCurve Networking Antenna Deployment Technical Brief Introduction... 2 Antenna types... 2 Omni directional antennas... 2 Directional antennas... 2 Diversity antennas... 3 High gain directional antennas...

### Understanding Range for RF Devices

Understanding Range for RF Devices October 2012 White Paper Understanding how environmental factors can affect range is one of the key aspects to deploying a radio frequency (RF) solution. This paper will

### 102 26-m Antenna Subnet Telecommunications Interfaces

DSMS Telecommunications Link Design Handbook 26-m Antenna Subnet Telecommunications Interfaces Effective November 30, 2000 Document Owner: Approved by: Released by: [Signature on file in TMOD Library]

### Microwave Antennas and Radar. Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8

Microwave Antennas and Radar Maria Leonora Guico Tcom 126 2 nd Sem Lecture 8 G P P directional isotropic Antenna Basics Isotropic Dipole High gain directional 0 db i 2.2 db i 14 db i Antenna performance

### The Need for Precise Timing in RF Power Measurements

Introduction This application note explains the functions and applications of a powerful unique feature of the SeeGull EX and MX Scanning Receivers: the Enhanced Power Scan (EPS). Unlike standard tools,

### Robot Perception Continued

Robot Perception Continued 1 Visual Perception Visual Odometry Reconstruction Recognition CS 685 11 Range Sensing strategies Active range sensors Ultrasound Laser range sensor Slides adopted from Siegwart

### RADIO FREQUENCY INTERFERENCE AND CAPACITY REDUCTION IN DSL

RADIO FREQUENCY INTERFERENCE AND CAPACITY REDUCTION IN DSL Padmabala Venugopal, Michael J. Carter*, Scott A. Valcourt, InterOperability Laboratory, Technology Drive Suite, University of New Hampshire,

### Characterizing Wireless Network Performance

Characterizing Wireless Network Performance Ruckus Wireless Black Paper Accurate performance testing for wireless networks requires understanding how to test for worst case scenarios As expensive and inconvenient

### Internal GPS Active Patch Antenna Application Note

Internal GPS Active Patch Antenna Application Note APN-13-8-002/A Page 1 of 14 1. BASICS 2. APPLICATIONS 3. SIZE 4. SHAPE 5. GROUND PLANE 6. IMPEDANCE 7. BANDWIDTH 8. VSWR 9. LINK BUDGET 10. GAIN 11. NOISE

### RESULTS OF THE LABORATORY EVALUATION OF AN 8 MHz ADTB-T TELEVISION SYSTEM FOR TERRESTRIAL BROADCASTING FINAL REPORT (VERSION 3.

RESULTS OF THE LABORATORY EVALUATION OF AN 8 MHz ADTB-T TELEVISION SYSTEM FOR TERRESTRIAL BROADCASTING FINAL REPORT (VERSION 3.0) Prepared by the COMMUNICATIONS RESEARCH CENTRE CANADA For HDTV TEEG CHINA

### Measured Performance of 5-GHz a Wireless LAN Systems

Measured Performance of 5-GHz 802.11a Wireless LAN Systems IEEE 802.11a systems take advantage of higher data rates and more frequency spectrum to deliver good range and improved system capacity performance.

### Indoor Path Loss. Contents. Application Note. XST-AN005a-Indoor June Link Margin...2. Indoor Communications...4. Situational Analysis...

Indoor Path Loss Contents Link Margin...2 Indoor Communications...4 Situational Analysis...5 Conclusion...6 Application Note XST-AN005a-Indoor June 2012 Website: Email: www.digi.com rf-experts@digi.com

### Cellular Network Planning and Optimization Part IV: Antennas. Jyri Hämäläinen, Communications and Networking Department, TKK, 18.1.

Cellular Network Planning and Optimization Part IV: Antennas Jyri Hämäläinen, Communications and Networking Department, TKK, 18.1.007 Basics Preliminaries Note: In the following we concentrate on the base

### RF Measurements Using a Modular Digitizer

RF Measurements Using a Modular Digitizer Modern modular digitizers, like the Spectrum M4i series PCIe digitizers, offer greater bandwidth and higher resolution at any given bandwidth than ever before.

### TCOM 370 NOTES 99-4 BANDWIDTH, FREQUENCY RESPONSE, AND CAPACITY OF COMMUNICATION LINKS

TCOM 370 NOTES 99-4 BANDWIDTH, FREQUENCY RESPONSE, AND CAPACITY OF COMMUNICATION LINKS 1. Bandwidth: The bandwidth of a communication link, or in general any system, was loosely defined as the width of

### Lab Exercise: Antenna Basics

Experiment Objectives: Lab Exercise: Antenna Basics In this lab you will analyze received radar signals from the P400 to gain an understanding of the basics of electromagnetic antennas. This lab will demonstrate

### T = 1 f. Phase. Measure of relative position in time within a single period of a signal For a periodic signal f(t), phase is fractional part t p

Data Transmission Concepts and terminology Transmission terminology Transmission from transmitter to receiver goes over some transmission medium using electromagnetic waves Guided media. Waves are guided

### Introduction t o to Wireless Wireless Communication

Introduction to Wireless Communication History of wireless communication Guglielmo Marconi invented the wireless telegraph in 1896 Communication by encoding alphanumeric characters in analog signal Sent

### Cellular Wireless Antennas

Cellular Wireless Antennas A Technical Brief GarrettCom Inc., November 2010 Overview The Cellular Wireless Antenna Technical brief is provided to assist with the design and deployment of the DX940 Cellular

### Outlines. LECTURE 3: Wireless Transmission Technologies. Wireless Transmission on Unguided Media

LECTURE 3: Wireless Transmission Technologies CIS 472 Wireless Communications and Networks Winter 2016 Instructor: Dr. Song Xing Outlines Wireless Data Transmission Modulation Spread Spectrum Department

Benha Faculty of Engineering Electrical Engineering Department 5 th Year Telecommunication Final Exam: 26 May 2012 Examiner: Dr. Hatem ZAKARIA Time allowed: 3 Hours Radio and Television (E522) Answer All

### Detection of Leak Holes in Underground Drinking Water Pipelines using Acoustic and Proximity Sensing Systems

Research Journal of Engineering Sciences ISSN 2278 9472 Detection of Leak Holes in Underground Drinking Water Pipelines using Acoustic and Proximity Sensing Systems Nanda Bikram Adhikari Department of

### Application Note Noise Frequently Asked Questions

: What is? is a random signal inherent in all physical components. It directly limits the detection and processing of all information. The common form of noise is white Gaussian due to the many random

### Internal GPS Active Patch Antenna Application Note

Internal GPS Active Patch Antenna Application Note APN-13-8-002/B/JC Page 1 of 17 1. BASICS 2. APPLICATIONS 3. SIZE 4. SHAPE 5. GROUND PLANE 6. IMPEDANCE 7. BANDWIDTH 8. VSWR 9. LINK BUDGET 10. GAIN 11.

### Technical Article Developing Software for the CN3 Integrated GPS Receiver

Technical Article Developing Software for the CN3 Integrated GPS Receiver 1 Intermec Technologies Table of Contents INTRODUCTION... 3 AN OVERVIEW OF GPS TECHNOLOGY... 3 What is GPS?... 3 How GPS works...

### Maximizing Range. Contents. Application Note. XST-AN010a June 2012. Abstract...1 RF Communication Systems...1 Installing an RF System...

Maximizing Range Contents Abstract...1 RF Communication Systems...1 Installing an RF System...5 Application Note XST-AN010a June 2012 Website: Email: www.digi.com rf-experts@digi.com Abstract This document

### RF Coverage Validation and Prediction with GPS Technology

RF Coverage Validation and Prediction with GPS Technology By: Jin Yu Berkeley Varitronics Systems, Inc. 255 Liberty Street Metuchen, NJ 08840 It has taken many years for wireless engineers to tame wireless

### Sound Power Measurement

Sound Power Measurement A sound source will radiate different sound powers in different environments, especially at low frequencies when the wavelength is comparable to the size of the room 1. Fortunately

### Glossary of RTLS/RFID Terms

Glossary of RTLS/RFID Terms A Active tag: An RFID tag that has a transmitter to send back information, rather than reflecting back a signal from the reader, as a passive tag does. Most active tags use

### GNSS Parameters. Position estimation uncertainties

GNSS Parameters Position estimation uncertainties Petr Bureš, bures@fd.cvut.cz Faculty of transportation sciences Czech technical university in Prague Contents Satellite systems in general Accuracy Position

### Divvela.Santhosh Raghava Rao [1],Sreevardhan cheerla [2]

Signal Strength Enhancement Using Cellular Repeater On Three Frequency Bands For Low Signal Coverage Areas (GSM900, GSM 1800/DCS, 3G) Divvela.Santhosh Raghava Rao [1],Sreevardhan cheerla [2] [1] B.tech

### REALIZATION OF FAST ACQUISITION FOR SPREAD SPECTRUM SIGNAL BASED ON FFT

REALIZATION OF FAST ACQUISITION FOR SPREAD SPECTRUM SIGNAL BASED ON FFT QI Jian-zhong, Gong Yang, Song Peng College of Information Engineering, North China University of Technology, China ABSTRACT Acquisition

### This Antenna Basics reference guide includes basic information about antenna types, how antennas work, gain, and some installation examples.

Antenna Basics This Antenna Basics reference guide includes basic information about antenna types, how antennas work, gain, and some installation examples. What Do Antennas Do? Antennas transmit radio

### Results of IMES (Indoor Messaging System) Implementation for Seamless Indoor Navigation and Social Infrastructure Platform

Results of IMES (Indoor Messaging System) Implementation for Seamless Indoor Navigation and Social Infrastructure Platform Dinesh Manandhar, Seiya Kawaguchi, Hideyuki Torimoto GNSS Technologies Inc., Japan

### An Algorithm for Automatic Base Station Placement in Cellular Network Deployment

An Algorithm for Automatic Base Station Placement in Cellular Network Deployment István Törős and Péter Fazekas High Speed Networks Laboratory Dept. of Telecommunications, Budapest University of Technology

### Antenna Basic Concepts

ANTENNA An antenna is a device to transmit and/or receive electromagnetic waves. Electromagnetic waves are often referred to as radio waves. Most antennas are resonant devices, which operate efficiently

### A comparison of radio direction-finding technologies. Paul Denisowski, Applications Engineer Rohde & Schwarz

A comparison of radio direction-finding technologies Paul Denisowski, Applications Engineer Rohde & Schwarz Topics General introduction to radiolocation Manual DF techniques Doppler DF Time difference

### Solving Simultaneous Equations and Matrices

Solving Simultaneous Equations and Matrices The following represents a systematic investigation for the steps used to solve two simultaneous linear equations in two unknowns. The motivation for considering

### SpotFi: Decimeter Level Localization Using WiFi

SpotFi: Decimeter Level Localization Using WiFi Hasan Faik Alan Kotaru, Manikanta, Kiran Joshi, Dinesh Bharadia, and Sachin Katti. "SpotFi: Decimeter Level Localization Using WiFi." In Proceedings of the

### CHAPTER4 GENERAL ASPECTS OF MUTUAL

CHAPTER4 GENERAL ASPECTS OF MUTUAL ADMITTANCE OF CPW-FED TWIN SLOTS ON CONDUCTOR-BACKED TWO-LAYER SUBSTRATES 4.1 INTRODUCTORY REMARKS The present chapter is concerned with an exploratory investigation

### Line 6 Guide to XD-V70 Antenna Setup

Line 6 Guide to XD-V70 Antenna Setup Electrophonic Limited Edition - Rev C Introduction This guide provides information helpful in ensuring maximum performance when using Line 6 XD-V70 wireless systems

### ANALYZER BASICS WHAT IS AN FFT SPECTRUM ANALYZER? 2-1

WHAT IS AN FFT SPECTRUM ANALYZER? ANALYZER BASICS The SR760 FFT Spectrum Analyzer takes a time varying input signal, like you would see on an oscilloscope trace, and computes its frequency spectrum. Fourier's

### APPLICATION NOTE GaGe CompuScope 14200-based Lightning Monitoring System

APPLICATION NOTE GaGe CompuScope 14200-based Lightning Monitoring System Challenge A customer needed to upgrade an older data acquisition unit for a real-time lightning monitoring system. Unlike many lightning

### 802.11n in the Outdoor Environment

POSITION PAPER 802.11n in the Outdoor Environment How Motorola is transforming outdoor mesh networks to leverage full n advantages Municipalities and large enterprise customers are deploying mesh networks

### LTE Evolution for Cellular IoT Ericsson & NSN

LTE Evolution for Cellular IoT Ericsson & NSN LTE Evolution for Cellular IoT Overview and introduction White Paper on M2M is geared towards low cost M2M applications Utility (electricity/gas/water) metering

### You will need the following pieces of equipment to complete this experiment:

UNIVERSITY OF TORONTO FACULTY OF APPLIED SCIENCE AND ENGINEERING The Edward S. Rogers Sr. Department of Electrical and Computer Engineering ECE422H1S: RADIO AND MICROWAVE WIRELESS SYSTEMS EXPERIMENT 3:

### RECOMMENDATION ITU-R RA (Question ITU-R 145/7)

Rec. ITU-R RA.769-1 1 RECOMMENDATION ITU-R RA.769-1 PROTECTION CRITERIA USED FOR RADIOASTRONOMICAL MEASUREMENTS (Question ITU-R 145/7) (1992-1995) Rec. ITU-R RA.769-1 The ITU Radiocommunication Assembly,

### VOICE OVER WI-FI CAPACITY PLANNING

VOICE OVER WI-FI CAPACITY PLANNING Version 1.0 Copyright 2003 Table of Contents Introduction...3 Wi-Fi RF Technology Options...3 Spectrum Availability and Non-Overlapping Wi-Fi Channels...4 Limited

### A Note on the Effects of Broadcast Antenna Gain, Beam Width and Height Above Average Terrain

A Note on the Effects of Broadcast Antenna Gain, Beam Width and Height Above Average Terrain John L. Schadler - Director of Antenna Development Dielectric L.L.C. Raymond, ME 30 September 2014 Abstract

### Radio Physics for Wireless Devices and Networking. The Radio Physics of WiFi. By Ron Vigneri

Radio Physics for Wireless Devices and Networking By Ron Vigneri The Radio Physics of WiFi The standard for wireless LANs (WLANs) was completed in 1997 with the release of the IEEE 802.11 specification

### Unmatched RF Spectrum Analysis

Datasheet: AirMagnet Spectrum XT AirMagnet Spectrum XT is the industry s first professional spectrum analyzer solution that combines in-depth RF analysis with real-time WLAN information for quicker and

### The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper

The Effective Number of Bits (ENOB) of my R&S Digital Oscilloscope Technical Paper Products: R&S RTO1012 R&S RTO1014 R&S RTO1022 R&S RTO1024 This technical paper provides an introduction to the signal

### WiMAX Performance Analysis under the Effect of Doppler s Shift

WiMAX Performance Analysis under the Effect of Doppler s Shift Navgeet Singh 1, Amita Soni 2 1, 2 Department of Electronics and Electrical Engineering, PEC University of Technology, Chandigarh, India Abstract:

### USB 3.0* Radio Frequency Interference Impact on 2.4 GHz Wireless Devices

USB 3.0* Radio Frequency Interference Impact on 2.4 GHz Wireless Devices White Paper April 2012 Document: 327216-001 INFORMATION IN THIS DOCUMENT IS PROVIDED IN CONNECTION WITH INTEL PRODUCTS. NO LICENSE,

### MobileMapper 6 White Paper

MobileMapper 6 White Paper Meter-Level Mapping Accuracy With Post-Processing Introduction Since its introduction in February 2008, the Magellan MobileMapper 6 has been welcomed by the market as the only

### SmartDiagnostics Application Note Wireless Interference

SmartDiagnostics Application Note Wireless Interference Publication Date: May 27, 2015 KCF Technologies, Inc. Background The SmartDiagnostics wireless network is an easy to install, end-to-end machine

### Antenna Selection for Optimum Wireless LAN Performance

Antenna Selection for Optimum Wireless LAN Performance Dr. Steven R. Best Cushcraft Corporation 48 Perimeter Road Manchester, NH 03108 (603) 627-7877 PURPOSE Overview of antenna properties and performance

### communication over wireless link handling mobile user who changes point of attachment to network

Wireless Networks Background: # wireless (mobile) phone subscribers now exceeds # wired phone subscribers! computer nets: laptops, palmtops, PDAs, Internet-enabled phone promise anytime untethered Internet

### Chapter 6. Single Sideband Transmitter Tests and Measurements

Chapter 6 Single Sideband Transmitter Tests and Measurements This chapter deals with the basic tests and measurements that can be used to evaluate the performance of single sideband suppressed carrier

### Propagation Channel Emulator ECP_V3

Navigation simulators Propagation Channel Emulator ECP_V3 1 Product Description The ECP (Propagation Channel Emulator V3) synthesizes the principal phenomena of propagation occurring on RF signal links

### Static Environment Recognition Using Omni-camera from a Moving Vehicle

Static Environment Recognition Using Omni-camera from a Moving Vehicle Teruko Yata, Chuck Thorpe Frank Dellaert The Robotics Institute Carnegie Mellon University Pittsburgh, PA 15213 USA College of Computing

### Overcoming the Challenges of 4G LTE and MIMO for In-Tunnel Wireless Connectivity

Page 1 Overcoming the Challenges of 4G LTE and MIMO for In-Tunnel Wireless Connectivity Written by Axel Schroeder April 2014 Page 2 Abstract As mobile wireless continues to make the transition to data

### Log-Likelihood Ratio-based Relay Selection Algorithm in Wireless Network

Recent Advances in Electrical Engineering and Electronic Devices Log-Likelihood Ratio-based Relay Selection Algorithm in Wireless Network Ahmed El-Mahdy and Ahmed Walid Faculty of Information Engineering

### 8. Cellular Systems. 1. Bell System Technical Journal, Vol. 58, no. 1, Jan 1979. 2. R. Steele, Mobile Communications, Pentech House, 1992.

8. Cellular Systems References 1. Bell System Technical Journal, Vol. 58, no. 1, Jan 1979. 2. R. Steele, Mobile Communications, Pentech House, 1992. 3. G. Calhoun, Digital Cellular Radio, Artech House,

### Design of an U-slot Folded Shorted Patch Antenna for RF Energy Harvesting

Design of an U-slot Folded Shorted Patch Antenna for RF Energy Harvesting Diponkar Kundu, Ahmed Wasif Reza, and Harikrishnan Ramiah Abstract Novel optimized U-slot Folded Shorted Patch Antenna (FSPA) is

### Mobile Phone Location Tracking by the Combination of GPS, Wi-Fi and Cell Location Technology

IBIMA Publishing Communications of the IBIMA http://www.ibimapublishing.com/journals/cibima/cibima.html Vol. 2010 (2010), Article ID 566928, 7 pages DOI: 10.5171/2010.566928 Mobile Phone Location Tracking

### The Effect of Network Cabling on Bit Error Rate Performance. By Paul Kish NORDX/CDT

The Effect of Network Cabling on Bit Error Rate Performance By Paul Kish NORDX/CDT Table of Contents Introduction... 2 Probability of Causing Errors... 3 Noise Sources Contributing to Errors... 4 Bit Error

### MATRIX TECHNICAL NOTES

200 WOOD AVENUE, MIDDLESEX, NJ 08846 PHONE (732) 469-9510 FAX (732) 469-0418 MATRIX TECHNICAL NOTES MTN-107 TEST SETUP FOR THE MEASUREMENT OF X-MOD, CTB, AND CSO USING A MEAN SQUARE CIRCUIT AS A DETECTOR

### EPFD Measurements on GPS and Iridium at the RPA

ATA Memo #53 EPFD Measurements on GPS and Iridium at the RPA Nia Imara July 2002 ABSTRACT The 3.2 m diameter reflectors of the RPA are well calibrated in absolute gain, antenna pattern and system noise

### REFERENCE GUIDE EXTERNAL ANTENNA GUIDE

REFERENCE GUIDE EXTERNAL ANTENNA GUIDE Xirrus External Antennas Guide Overview To optimize the overall performance of a Xirrus WLAN in an outdoor deployment it is important to understand how to maximize

### AIR DRM. DRM+ Showcase

AIR DRM DRM+ Showcase New Delhi, 23 rd 27 th May 2011 The Report was prepared by Digital Radio Mondiale Consortium (DRM) & All India Radio (AIR) Version: 2011-07-26 Index: 1. Introduction 2. DRM+ System

### Antenna Diversity in Wireless Local Area Network Devices

Antenna Diversity in Wireless Local Area Network Devices Frank M. Caimi, Ph.D. Kerry L. Greer Jason M. Hendler January 2002 Introduction Antenna diversity has been used in wireless communication systems

### MEDIA TECHNOLOGY & INNOVATION. General issues to be considered when planning SFNs

EBU TECHNICAL MEDIA TECHNOLOGY & INNOVATION 13/03/09 General issues to be considered when planning SFNs 1. SFN networks In a Single Frequency Network (SFN), all transmitters in the network use the same

### Experiment 7: Familiarization with the Network Analyzer

Experiment 7: Familiarization with the Network Analyzer Measurements to characterize networks at high frequencies (RF and microwave frequencies) are usually done in terms of scattering parameters (S parameters).

### SMART ANTENNAS CHAPTER 6. Jack H. Winters INTRODUCTION

53 CHAPTER 6 SMART ANTENNAS Jack H. Winters INTRODUCTION Throughout the world, including the United States, there is significant research and development on smart antennas for wireless systems. This is

### Environmental Monitoring: Guide to Selecting Wireless Communication Solutions

Environmental Monitoring: Guide to Selecting Wireless Communication Solutions By: Scott South Published in WaterWorld, January 2005 (Page 48) Rapidly growing demands for information and increased productivity