Mobility

Effect of Power and Rate Adaptation on the Spectral Efficiency of MQAM/OFDM System Under Very Fast Fading Channels

Download Now Free registration required

Executive Summary

In this paper, the effect of power and rate adaptation on the spectral efficiency of Orthogonal Frequency Division Multiplexing (OFDM) systems using M-ary Quadrature Amplitude Modulation (MQAM) is investigated in the presence of frequency selective and very rapidly time-varying fading channels, under power and instantaneous Bit Error Rate (BER) constraints. Lower bounds on the maximum spectral efficiency of adaptive OFDM/MQAM systems with perfect and imperfect Channel State Information (CSI) are obtained, together with a closed-form expression for the average spectral efficiency of adaptive OFDM systems. The delay between the channel estimation and the actual transmission is also considered in this paper.

  • Format: PDF
  • Size: 309.7 KB