Dynamic bandwidth optimization for wireline and wireless channels

This paper describes the benefits of bandwidth optimization for wireline and wireless channels. Dynamic bandwidth optimization is performed by choosing the right symbol rate and/or the right frequency band to transmit over. Three parameters can be adjusted: power, rate, and margin. We start with a brickwall channel and generate analytic expressions for the improvement in performance-rate and margin -of a bandwidth optimized system versus an unoptimized one for different channel loads. We then develop bounds on the data rate increase from bandwidth optimization on any given channel with fixed margin and fixed total power. We show that for fixed power and data rate systems, the margin differential between optimized and unoptimized bandwidth increases with capacity. We conclude with an analysis of bandwidth optimization for wireless channels and the impact of channel mismatch errors on the performance of such systems.