Channel state-adaptive techniques for throughput enhancement in wireless broadband networks

Wireless broadband access is becoming increasingly popular in the telecommunications market due to the projected demand for flexible and easily deployable high, speed connections. In order to adhere to the volatility of the wireless medium, the adoption of sophisticated adaptation techniques is required. We investigate the problem of enhancing channel throughput by performing resource assignment and reuse with adaptation of physical layer parameters. We propose an algorithm to allocate channels to users with different rate requirements, while appropriately adjusting the modulation level and transmission power, based on instantaneous channel quality. Our algorithm constructs the cochannel set of users in a sequential manner, by utilizing a criterion which is based on the induced and received amounts of interference for a user and the contribution in throughput increase. Although illustrated in the context of TDMA/TDD, the proposed technique can be applied in systems which support different multiple access and signaling schemes with orthogonal channels (e.g. OFDMA, CDMA). Our results indicate a considerable increase in throughput per utilized channel under such adaptive techniques.