... 1 968 [5] E Biglieri, J Proakis, and S Shamai, “Fading channels: information-theoretic and communications aspects,” IEEE Transactions on Information Theory, vol 44, no 6, pp 261 9– 269 2, 1998 1298 ... example, with antenna elements, both mobiles can transmit at 0. 76 nat per second while achieve an outage probability smaller than 10% With 16 antenna elements at the base station, both mobiles can transmit ... second with an outage probability smaller than 1%; with 16 antenna elements at the base station, the mobiles can simultaneously transmit at 2 .65 nat per second with an outage probability smaller...
... Then ( 26) and (27) can be combined to obtain Ryy − Γ = X · Rhh · XH + X · Rhh · PH + P · Rhh · XH + P · Rhh · PH = X + P · Rhh · X + P H (29) Combining the intermediate results from (24) to (29) , ... of CDMA with random spreading,” IEEE Transactions on Information Theory, vol 45, no 2, pp 62 2 64 0, 1999 [6] A J Viterbi, “Very low rate convolutional codes for maximum theoretical performance of ... in Proceedings of IEEE Global Telecommu- [15] [ 16] [17] [18] [19] [20] [21] [22] [23] [24] [25] [ 26] nications Conference (GLOBECOM ’05), vol 6, pp 3513–3517, St Louis, Mo, USA, November-December...
... = D8 = · · · = D12 = 2D Thus, we have SIR = √ 3Qdr √ κ 3Q = + 6/ 2κ −κ dr−κ √ + 3Qdr −κ (1.20) which leads to Q= + 6/ 24 ∗ 101.8 = 6. 68 (1.21) Clearly, including the second tier of interferers makes ... 10 Rearranging, we have ≤ 3Q (1. 16) √ ∗ 101.8 = 6. 48 Q≥ (1.17) P1: IML/FFX P2: IML/FFX MOBK023-01 MOBK023-Buehrer.cls 12 QC: IML/FFX T1: IML September 28, 20 06 15:54 CODE DIVISION MULTIPLE ACCESS ... (CDMA) The smallest valid value of Q greater than 6. 48 is then Q = (i = 2, j = 1) Thus, the maximum number of allowable channels per cell is 450 = 64 K= (1.18) Now, if we include the second tier...
... R9,11 R45 ,62 0 .6 0.4 0.2 Cross-correlation P1: IML/FFX MOBK023-02 0.2 0.4 0 .6 −20 −15 −10 −5 Delay (chips) 10 15 20 FIGURE 2 .6: Example cross-correlation functions for Walsh codes of length 64 for ... 20 06 15:54 SPREAD SPECTRUM TECHNIQUES FOR CODE DIVISION MULTIPLE ACCESS 33 TABLE 2.1: Code length N and the number of m-sequences Np (n) n 10 N = 2n − 15 31 63 127 255 511 1023 Np (n) 2 6 18 16 ... 2 .6 The cross-correlation is plotted for various Walsh codes of length 64 We can see that only at zero delay (i.e., n = 0) we obtain Ri, j n = P2: IML MOBK023-Buehrer.cls 32 September 28, 2006...
... the SIR is −110dBm + 130dBm = 20dB and the standard deviation √ is + 36 = 6. 08dB Converting to base e , 20 ln (10) 10 = 4 .61 6. 08 ln (10) σ = 10 = 1.40 μ= (3.2) (3.3) Now we wish to find X such ... MOBK023-Buehrer.cls 74 September 28, 20 06 15:55 CODE DIVISION MULTIPLE ACCESS (CDMA) 0.02 signals signals 20 signals 0.018 0.0 16 0.014 0.012 0.01 0.008 0.0 06 0.004 0.002 0 500 1000 1500 Total interference ... perform all calculations in base 10 The probability that the SNR exceeds 6dB is Pr{SIR} ≥ 1 06/ 10 = − Q = − Q (1.15) = 0.88 μ 6 σ (3.18) Thus, the probability of exceeding the threshold is only 88%...
... Specifically, lim ηUL = (3 .66 a) ηUL = (3 .66 b) Itotal →∞ lim (Iic +Io c )→0 P2: IML MOBK023-Buehrer.cls 108 September 28, 20 06 15:55 CODE DIVISION MULTIPLE ACCESS (CDMA) Now, rearranging (3 .64 ), we can write ... termed system load, which for CDMA systems can be defined as ηUL = − σn Itotal (3 .64 ) where Itotal = Iic + Io c + σn (3 .65 ) σn is the receiver thermal noise power, Iic is the in-cell interference, ... separate load levels, which we will call Limit A and Limit B Limit A is typically 60 % of pole capacity for the uplink (or 60 % of the transmit power for the downlink) and is the limit at which a base...
... MOBK023-04 P2: IML MOBK023-Buehrer.cls September 28, 20 06 15:55 1 26 P1: IML/FFX MOBK023-05 P2: IML MOBK023-Buehrer.cls September 28, 20 06 15: 56 127 CHAPTER Multiuser Detection As discussed in previous ... dispreading Decisions are then made as b = sgn y (5 .6) P1: IML/FFX MOBK023-05 P2: IML MOBK023-Buehrer.cls September 28, 20 06 15: 56 MULTIUSER DETECTION 129 where the function sgn(x) is applied element-by-element ... frequency selective Rician fading channels [64 , 65 ] as well as flat and frequency selective Rayleigh fading channels (both coherent and differentially coherent) [66 –71] The most notable difference between...
... Letters, vol 2, no 2, pp 36 38, 1998.doi:10.1109/4234 .66 07 96 P1: IML/FFX P2: IML/FFX MOBK023-BIB QC: IML/FFX MOBK023-Buehrer.cls T1: IML September 28, 20 06 17:14 BIBLIOGRAPHY 175 [29] D Hibbard, “On ... 580–592, May 1994.doi:10.1109/49.2 866 65 [66 ] Z Zvonar and D Brady, “Multiuser detection in single-path fading channels,” IEEE Transactions on Communications, vol 42, pp 1 729 1739, February/March/April ... September 1998.doi:10.1109/35.71 461 6 [ 26] T Kasami, “Weight distribution formula for some class of cyclic codes,” University of Illinois – Urbana, Tech Rep R-285, April 1 966 [27] L R Welch, “Lower bounds...
... cầu (GSA) công nghệ 3,5G (HSDPA) chiếm đến 69 % tổng số mạng di động toàn cầu Nếu 20 06, có 166 mạng di động hỗ trợ HSDPA 75 nước, kết thúc năm 2007, số nhà mạng sử dụng công nghệ 204, 89 quốc ... tốc độ mạng không Có tới 62 % số mạng có tốc độ download cao 3 ,6 MB/giây, có 21% số mạng đạt 7,2 MB/giây GSA cho rằng, phát triển mạng 3,5G ảnh hưởng đến dịch vụ băng tần toàn cầu, nhiều nhà mạng ... “tốc độ lên tới 3 .6 Mbit/giây”, song số đạt điều kiện lý tưởng Do vậy, tốc độ đường truyền không nhanh mong đợi, đặc biệt điều kiện phòng kín Tình hình triển khai HSDPA Theo số liệu Nghiệp đoàn...
... SYNCHRONIZATION AND CHANNEL ESTIMATION EVOLUTION OF WIMAX AND LTE Nhóm CONCLUSION INTRODUCTION - IEEE 802.16e-based WiMAX and Third Generation Partnership Project (3GPP)-based Long Term Evolution (LTE) are ... The pseudorandom sequence to be sent on the subcarriers is specified in is fixed the IEEE 802.16e standard - The Zadoff-Chu sequence loaded onto the subcarriers is specified in the - A mobile ... carriers to obtain wider Forming fixed size physical resource units (PRUs) Nhóm Base on the IEEE 802.16m standard WiMAXv2 and LTE-A CONCLUSION Nhóm This article has compared the use of OFDMA in WiMAX...
... bố từ trái sang phải khung truyền, thể hình 1a, số lượng sóng mang sử dụng ký tự OFDM giảm Sử dụng phân tập tầnsố Cả WiMAX LTE gặp fading tầnsố có chọn lọc sử dụng băng thông rộng [1, 2] Điều ... thách thức số pilots bị hạn chế số lượng tiles bị chiếm người dùng Bởi chuỗi preamble PN điều chế sóng mang thứ 3, tầnsố lớn bù đắp ước lượng cách tương quan phần chu kì preamble 16. 4 KHz Hiệu ... 802.11n Một số nhược điểm tỷ số công suất đỉnh công suất trung bình(PAPR) có lý không sử dụng OFDMA cho đường lên LTE Tuy nhiên, WiMAX, sử dụng thông minh tài nguyên thời gian -tần số giảm bớt...