Linear prediction at base station for closed loop power control
Sangho Choe, Tatcha Chulajata, H.M. Kwon, Byung-Jin Koh, Sung-Cheol Hong · 2003
A closed loop power control (CLPC) with linear prediction at a base station has been investigated for the reverse link in a code division multiple access (CDMA) system. Several algorithms, e.g., Durbin-Levinson (DL), least minimum square error (LMS), recursive least square (RLS), and Burg, are applied to predict the received signal bit energy to interference power spectral density (Eb/Io) at a base station with a finite impulse response (FIR) filter. It is observed that with perfect channel estimation, the simulation results show that 1 dB improvement in Eb/Io can be made at a certain frame error rate (FER), compared to the existing IS-95 closed loop power control scheme. However, with practical channel estimation obtained by employing these prediction algorithms, insignificant FER improvement is observed. The group delay introduced by a prediction algorithm is a major reason to cause the insignificant improvement.