Upstream Channel Structure for Bidirectional LMDS using CDMA
Lim Hyung Rae, Cho Byung Lok · The Transactions of the Korea Information Processing Society · 1999
In this paper, we propose the method using coherent detection with time division multiple pilot signal for each users I reverse CDMA channel as the structure of reverse CDMA channel to apply CDMA to upstream channel of bidirectional LMDS. By using coherent detection with pilot signal in reverse CDMA channel, capacity can be improved when compared with noncoherent detection, but it is required to allocate pilot signal for all user. And then interference is increased due to allocate continuously the pilot signals. In this case channel capacity is decreased. The method f pilot allocation is needed that reduce this interference and keep synchronization effect using coherent detection, In the reverse link, the pilot allocated to each users at different time and not overlapped is possible solution for it. this pilot is proposed and analyzed its performance and capacity. The result is that proposed method has more increased capacity compared wit others.