Method and apparatus for adaptively compensating channel or system variations in precoded communications system

摘要

The present invention relates to a method and apparatus for adaptively compensating for channel or system variations in which adaptive compensation is used in the receiver of a digital communication system. The transmitter of the digital communication system includes precoding. The adaptive receiver compensation mitigates the interferences not removed by the transmitter precoder. In an embodiment of the invention, the adaptive compensation can be performed using an adaptive feedforward filter (FFF) and a feedback filter (FBF) in the receiver. The FBF output is generated based on previous values of estimates of the transmitted precoded sequence. The determined value of the FBF coefficients can be periodically relayed to the transmitter to update the precoder coefficients of the transmitter. Alternatively, the value of the FBF coefficients can be relayed to the transmitter after the value of the coefficients exceeds a predetermined threshold. Accordingly, the receiver adaptively and automatically compensates for misadjustments of the fixed transmitter precoder with respect to the actual channel at a given point in time.