Opportunistic Scheduling for Uplink Cognitive Cellular Networks with Outage Protection of the Primary User

This letter advocates a novel opportunistic scheduling strategy for an uplink cognitive cellular network, as considered in [1]. Different from previous proposals, the proposed strategy chooses the cognitive user (CU) with the best instantaneous channel quality in addition to guaranteeing the reliable operation of primary user (PU). For such a strategy, it is analytically shown that in comparison with previous proposals, a greater average rate and a lower average bit error rate (BER) can be achieved. Interestingly, it is manifested that with an increase in the number of CUs, both the average rate and the average BER of the proposed strategy are ameliorated. Moreover, it is indicated that under the same outage protection criterion for the PU, a much lower transmit power is sufficient for the proposed strategy to optimize the system performance especially for a large number of CUs , as compared with previous strategies.