Multi-Level Weighted Combining of Retransmitted Vectors in Wireless Communications

This paper proposes weighted combining of retransmitted vectors for improved data recovery in single and multiple-antenna wireless LAN transceivers. Combining is suggested at multiple levels in the receiver design: at the post-equalizer, post-demapper and post-decoder stages. The best performance is obtained by exploiting diversity in time, equivalent to performing maximal-ratio combining of the information from repeated transmissions of the same data packet, separated in time (MRC-In-Time), over a SISO or MIMO WLAN channel. The proposed schemes can also be applied to a cooperative-diversity scenario where a receiver combines transmissions of the same message from multiple sources.