Adaptive Threshold Based Relay Selection for Minimum Feedback and Channel Usage
The authors propose adaptive threshold based relay selection scheme for type-2 (user equipment) relay that requires only minimum 1-bit feedback, for which each relay reports to the source if its R-D (Relay-Destination) instantaneous channel gain is above threshold (i.e., available). A source then selects the best relay among those that yields the highest S-R (Source-Relay) instantaneous gain, provided threshold is adjusted according to a target Signal-to-Noise Ratio (SNR). Exact and upper bound on the Symbol-Error Rate (SER) are derived for ??'?-PSK signaling to show that the proposed scheme provides the SER performance close to that of an optimal scheme.