Orthogonal Space–Time Block Code Over Time-Varying Flat-Fading Channels: Channel Estimation, Detection, and Performance Analysis

This paper studies the channel estimation, detection and performance analysis of mobile wireless communication systems employing space-time block codes (STBC), where the channels exhibit flat Rayleigh fading with a significant amount of Doppler spread. Pilot-symbol-assisted modulation (PSAM) is developed to estimate the channels. The performance of the channel estimation is evaluated. Maximum-likelihood (ML) detection is first formulated. A linear detector, called the symmetric linear (SL) detector, is proposed. An interference cancellation (IC) detector is also developed to improve the performance of the SL detector. We derive the closed-form analytical expressions for the bit-error rate (BER) or symbol-error rate (SER) of pilot-sequence-assisted STBC with binary phase-shift keying (PSK), quaternary PSK, 16-quadrature amplitude modulation (QAM) and 64-QAM, when the SL and IC detectors are used. Some important design issues in the pilot-sequence-assisted STBC systems, including the selection of pilot spacing and interpolator size, are discussed. Simulation results are presented that verify our analytical results. The tradeoffs between the performance and complexity for ML, SL, and IC detection are also discussed