CQI Reporting Strategies for Nonregenerative Two-Way Relay Networks
This paper considers data exchange between two terminals in a non-regenerative two-way relay network. The authors first propose two efficient Channel Quality Indicator (CQI) reporting schemes based on XOR and superposition coding for single-relay networks. These schemes allow two terminals to simultaneously estimate the CQI of the distant link without incurring additional overhead. In addition, the transmission time for CQI feedback is reduced by half while the loss of performance is negligible. Upper and lower bounds of the Mean Square Error (MSE) of the estimated CQI are derived to analyze various effects on the performance of the proposed schemes.