Cooperative Spatial Multiplexing for CR Users Sharing a Common Channel with Primary Users*

To enable mobile stations (MSs) of secondary users (SUs) in cognitive radio (CR) networks sharing a common channel with MSs of primary users (PUs) is an important but challenging issue. In this paper, a cooperative spatial multiplexing (CSM) scheme is proposed, where base station (BS) in CR network has K antennas and each SU or PU has one antenna only, and BS supports PUs and SUs by K spatial channels. To ensure communication quality of the network, the paper applies LDPC as the channel coding for BS, PUs and SUs. Simulations verify the proposed scheme with good spatial multiplexing capacity and BER performance.