... USA, 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 ... in ( 16) can be derived in closed form Each value C(h1 ) and C(h2 ) is the capacity of an AWGN channel with a single antenna element at the transmitter and m antenna elements at the receiver Thus ... uniformly distributed over (0, 2π] Thus, their joint probability density function is given by the product of the individual probability density functions [ 16] : pdf a1 , a2 , cos 2θ = g a1 g a2...
... 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 ... sequence,” in Proceedings of IEEE Global Telecommunication Conference (GLOBECOM ’99), vol 4, pp 2 162 –2 166 , Rio de Janeiro, Brazil, December 1999 A J Weiss and B Friedlander, “Channel estimation for...
... can be shown that D = 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 ... (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 ... 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...
... 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 ... 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% Examining ... 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...
... 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 ... ηUL (1 − ηUL )2 Itotal = (3 .68 ) − ηUL Thus, one way to estimate the interference increase due to a particular load increase is to use the approximation Itotal L (3 .69 ) I= − ηUL where the increase ... MOBK023-Buehrer.cls 120 September 28, 20 06 15:55 CODE DIVISION MULTIPLE ACCESS (CDMA) Solution: The two signals are transmitted at the same time, and thus the second signal arrives 60 0m/(3 ∗ 108 m/s) = μs This...
... 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 ... 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 ... PK + N N N N (5. 56) P1: IML/FFX MOBK023-05 P2: IML MOBK023-Buehrer.cls September 28, 20 06 15: 56 MULTIUSER DETECTION 145 70 Perfect cancellation assumption Linear cancellation 60 Normalized receive...
... MOBK023-Buehrer.cls 1 56 September 28, 20 06 15: 56 CODE DIVISION MULTIPLE ACCESS (CDMA) If we let M → ∞, M (−1)s Ps lim M→∞ = R−1 (5.89) s =0 provided that P p < where P p is the p-norm of matrix P Thus, as ... September 28, 20 06 15: 56 MULTIUSER DETECTION Probability of Bit Error 10 10 153 Matched Filter Stage Conv Decorrelator Stage Dec 10 SingleUser Bound 0.1 0.2 0.3 0.4 ρ 0.5 0 .6 0.7 0.8 0.9 FIGURE ... MOBK023-Buehrer.cls September 28, 20 06 15: 56 MULTIUSER DETECTION 10 Probability of Bit Error 10 10 155 Matched Filter Stage PIC Stage PIC Stage Partial Stage Partial 10 10 20 30 40 50 Users 60 70 80 90 FIGURE...
... liệu Nghiệp đoàn di động toàn 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 ... động băng thông rộng Ngoài ra, số lượng trạm thu phát HSDPA mặt đất tăng nhanh để đáp ứng nhu cầu thu phát liệu Được giới thiệu có “tốc độ lên tới 3 .6 Mbit/giây”, song số đạt điều kiện lý tưởng ... liệu theo phương thức Đây coi sản phẩm dòng 3.5G Công nghệ cho phép liệu download máy điện thoại có tốc độ tươngđương với tốc độ đường truyền ADSL, vượt qua cản trở cố hữu tốc độ kết nối điện...
... 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...
... IEEE 802.16m, có khả tương thích ngược với hệ thống WiMAX 802.16e tiêu chí quan trọng Với đặc điểm OFDMA, 802.16m không sử dụng ký hiệu kênh khái niệm PUSC phương pháp hình thành kênh tương tự ... đồng khung thu cách phát đồng trình tự (PSS),được gửi hai lần khung thời gian cố định mức 10 ms,không phân biệt băng thông hoạt động, trình tự gửi trung tâm có 64 sóng mang chiếm 0. 96 MHz băng ... antenna giống trường hợp antenna Số pilots thu nhỏ tương ứng để giữ lại giống phần mào đầu Nếu ghép kênh không gian sử dụng, pilots sử dụng hình dạng tương tự, số ký tự data tăng lên, dẫn tới...
... Algorithms 56 4.3.3 Frequency-domain Estimation 58 4.4 CRLB Analysis for LS Estimators 63 4.5 Numerical Results and Discussion 66 4.5.1 Performance of ... Fig.4 .6: Samples selection for channel estimation from FFT-demodulated OFDMA block 62 Fig.4.7: MSE performance of LS-T and LMMSE 68 Fig.4.8: Comparison between LS-T and LS-F 69 ... 2.2.2 Supplementary Schemes based on Conventional Detection 16 2.2.3 Non Conventional Detector-based Schemes 16 2.3 Problem Definition 17 2.3.1 Near-far Problem in...