Power optimization algorithm for OFDM underwater acoustic communication using adaptive channel estimation

Abstract

An adaptive channel estimation algorithm for the channel length is proposed to construct a channel estimation model suitable for orthogonal frequency division multiplexing (OFDM) underwater acoustic communication signals for the dependence of traditional channel estimation algorithms on channel length information. This algorithm can be adopted to evaluate channel estimation quality in real time and to adaptively adjust the channel length of the channel estimation algorithm according to the evaluation result, which satisfies the need of accurate estimation of unknown underwater acoustic channels and communication application; based on the study on the relationship between the OFDM communication bit error rate and the subcarrier signal to noise ratio, a self-adjusting optimization scheme for OFDM subcarrier transmitting power is proposed, which realizes underwater communication with the low bit error rate through higher energy efficiency. The validity of the research content is verified through simulation and field experiments.

On the Effect of Channel Knowledge in Underwater Acoustic Communications: Estimation, Prediction and Protocol

“…In this regard, OFDM adaptivity to the medium conditions is a relevant feature for the harsh propagation scenario offered by UWACs, allowing a significant increase in transmission rate. In [23], the authors propose an OFDM sub-carrier power optimization mechanism based on channel knowledge, achieved with a length-adaptive estimation technique. In [24], second-order statistics of the channel are exploited to derive the signal-to-interference-plus-noise ratio in each sub-carrier, so to realize adaptive coding and bit-power loading.…”