CONVOLUTIONAL CODED DS/CDMA WITH TWO SETS OF ORTHOGONAL SPREADING SEQUENCES AND ITERATIVE DETECTION  

作　　者：Wei Yimin Yi Xiaoxin Shen Yuehong(Nanjing Institute of Communication Engineering, Nanjing 210016) 

出　　处：《Journal of Electronics(China)》2002年第3期276-279,共4页电子科学学刊（英文版）

摘　　要：In this letter a convolutional coded Direct-Sequence Code-Division Multiple Ac-cess(DS/CDMA) concept is introduced. The number of the users it can accommodate is greater than the spreading factor N. Each of the available orthogonal spreading sequences of length N is assigned to one of the first N users which employ a common Pseudo-Noise (PN) scrambling sequence. When the number of users K exceeds N, say K= N + M with M < N, the M additional users reuse M of those orthogonal spreading sequences but in combination with another PN scrambling sequence. An iterative multistage detection technique aided by Viterbi decoding is used to cancel the interference between the two sets of users when K > N. The proposed technique thus accommodates N users without any mutual interference and a number of additional users almost without signal-to-noise ratio penalty.In this letter a convolutional coded Direct-Sequence Code-Division Multiple Ac-cess(DS/CDMA) concept is introduced. The number of the users it can accommodate is greater than the spreading factor N. Each of the available orthogonal spreading sequences of length N is assigned to one of the first N users which employ a common Pseudo-Noise (PN) scrambling sequence. When the number of users K exceeds N, say K= N + M with M < N, the M additional users reuse M of those orthogonal spreading sequences but in combination with another PN scrambling sequence. An iterative multistage detection technique aided by Viterbi decoding is used to cancel the interference between the two sets of users when K > N. The proposed technique thus accommodates N users without any mutual interference and a number of additional users almost without signal-to-noise ratio penalty.

关 键 词：Coded CDMA Cell capacity Multiple access 

分 类 号：TN929.533[电子电信—通信与信息系统]