Efficient CQI feedback via network coding for wireless relay networks

For the efficacy of radio resource management in downlink wireless relay networks, the channel quality indicator (CQI) between a mobile station (MS) and a relay station (RS) should be fed back from the RS to its base station (BS), at the cost of additional feedback overhead. In this letter, we propose an efficient feedback scheme based on network coding between a pilot sequence and the CQI of MS-RS link, through which the BS can have both CQIs of MS-RS and RS-BS links without overhead. Numerical results reveal that the proposed CQI reporting scheme has as good feedback performance as conventional one which generally requires additional feedback burden.