A traffic aware joint CQI feedback and scheduling scheme for multichannel downlink systems in TDD feedback mode

In this work we study the problem of channel state feedback and user scheduling in a single cell downlink wireless network employing multiple orthogonal parallel channels. The aspect of the system we are focusing on is stability. For user scheduling for stability as a performance measure, both the queue and channel states need to be known by the base station. However channel states can be known only via feedback from the receivers. In order to collect CQI feedback from each user at one channel, a fraction of the available time for transmission is used. This means that the time left to transmit is getting smaller. We present a joint feedback and scheduling algorithm which can guarantee an expansion of the stability region with respect to prior works. We also provide expressions regarding the distribution of the time needed to be devoted for feedback at each channel in some special cases. The proposed algorithm does not need knowledge of the statistics of the channels and traffic patterns. Simulations illustrate the operation of the proposed scheme.