Pilot-Based Channel Quality Reporting for OFDMA/TDD Systems with Cochannel Interference

This paper proposes a new uplink signalling to report the terminal´s channel quality in multiple subbands to the base station (BS) using channel reciprocity in orthogonal frequency division multiple access / time division duplex (OFDMA/TDD) systems. In the proposed method, the terminal transmits uplink pilot signals in the subbands with different transmit power which is inversely proportional to the subband- based interference-plus-noise power. The BS can obtain knowledge of the terminal´s received signal-to-interference-plus-noise power ratio (SINR) on subband basis, measuring the pilot signal power. In performance evaluation, accuracy of the channel quality reporting and amount of the control signalling are examined. From numerical results, it is found that the proposed method becomes effective as the number of subbands and terminals for channel quality reporting increases.