Detect spreading code for multi-user detector in TD-SCDMA downlink
Minying Sun, Ser Wah Oh · 2006
In the time division duplex (TDD) mode operation of UTRA (UMTS Terrestrial Radio Access), joint detection receiver is employed at the mobile terminal to improve the system performance. However, spreading codes for the co-existing users in one cell are not known to the mobile terminal. Active codes should be detected before multi-user detection is performed. A simple algorithm is to apply a bank of matched filters to the received signal using candidate spreading codes. The signal power of the matched filter output will indicate the existence of spreading code. We study this method and further improve the detection efficiency with the aid of channel impulse response (CIR) estimation and instantaneous signal to noise ratio (SNR) measurement. The robustness of the algorithm is shown via simulation results.