Carrier frequency offset recovery for CDMA array-receivers in selective Rayleigh-fading channels

Abstract

We propose a carrier frequency offset recovery (CFOR) module for CDMA to operate with STAR, the spatio-temporal array-receiver. The new CFOR module implements simple linear regression (LR), similar in approach to that implemented for time-delay synchronization in STAR. Simulations in selective Rayleigh-fading channels at various mobile speeds show that an increasing carrier frequency offset (CFO) severely degrades the capacity of a CDMA system, the relative loss being more significant at low mobility and transmission rate. CFOR with STAR reduces the effect of CFO and compensates almost completely the capacity loss. Relative capacity gains due to CFOR increase with the CFO. For nomadic voice and data-rates, the capacity gain is in the range of 270 and 150% respectively, at a CFO of about 1 ppm.