Adaptive Bit Allocation for OFDM Cognitive Radio Systems with Imperfect Channel Estimation

TL;DR

This paper proposes an adaptive bit allocation algorithm for OFDM cognitive radio systems that maximizes throughput under interference and imperfect channel estimation, ensuring reliable communication.

Contribution

It introduces a novel adaptive bit allocation method tailored for OFDM CR systems considering imperfect channel estimation effects.

Findings

The algorithm improves spectral efficiency in frequency selective fading environments.

Performance degradation due to imperfect channel estimation is analyzed.

The method maintains BER below a predefined threshold under interference.

Abstract

Cognitive radios hold tremendous promise for increasing the spectral efficiency of wireless communication systems. In this paper, an adaptive bit allocation algorithm is presented for orthogonal frequency division multiplexing (OFDM) CR systems operating in a frequency selective fading environment. The algorithm maximizes the CR system throughput in the presence of narrowband interference, while guaranteeing a BER below a predefined threshold. The effect of imperfect channel estimation on the algorithm's performance is also studied.