An Adaptive Bit and Power Allocation Algorithm for OFDM Systems with Eigenbeamforming

摘要

Adaptive bit and power allocation (ABPA) is a modulation scheme that assigns optimal symbol constellation sizes and powers across subcarriers in a multicarrier system to achieve a spectrally efficient transmission and maintain the system performance at a target level. We propose a lookup matrix ABPA (LM-ABPA) scheme which offers higher spectral efficiency for orthogonal frequency division multiplexing (OFDM) systems as compared to non-adaptive ones. By taking advantage of the correlation structure of the multi-input multi-output (MIMO) wireless channel, we incorporate LM-ABPA algorithm with eigen-beamforming to improve the error performance and thus further increase the overall spectral efficiency.