Optimal odd-periodic complementary sequences for diffuse wireless optical communications

Abstract

Indoor wireless optical communication (WOC) systems become promising because of their distinct advantages over their radio frequency counterparts. We address the optimal odd-periodic complementary sequences (OPCSs) for estimating a channel impulse response in WOC systems. Based on the Cramer-Rao bound, a criterion for design the optimal OPCSs is introduced. Optimum OPCSs are obtained and tabulated by computer search for different channel responses and OPCS length. Moreover, the sequence detection performance measured by bit error ratio (BER) for OPCSs-based channel estimation is also investigated. Simulation results show that the sequence detection performance can be significantly improved by using the optimal OPCS pairs. Moreover, the longer OPCS is, the better a BER performance can be obtained when the channel order is held fixed.