Adaptive Channel Estimation and Data Detection for Discontinuous Transmission in TD-SCDMA Systems

In the TD-SCDMA (time division synchronous code division multiple access) system, joint channel estimation (JCE) and joint detection (JD) take into account all users´ signals, and effectively estimate the channel impulse responses (CIRs) and detect the data symbols for all active users, respectively. If the discontinuous transmission (DTX) is employed in the system, both JCE and JD may process the active and non-active users´ signals together, but with high complexity and low accuracy. In this paper, adaptive JCE and JD are proposed to process only the active users´ signals with lower complexity, based on the known activity information from signaling. The simulation results show that adaptive JCE improves the channel estimation performance, and the combination of adaptive JCE and JD yields better system performance compared with conventional methods.