Iterative nonlinear detection for SFBC SC–FDMA uplink MIMO transmission systems

Abstract

Single-carrier frequency division multiple access (SC-FDMA) systems with space frequency block coding (SFBC) transmissions achieve both spatial and frequency diversity gains in wireless communications. However, SFBC SC-FDMA schemes using linear detectors suffer from severe performance deterioration because of noise enhancement propagation and additive noise presence in the detected output. Both issues are similar to inter-symbol-interference (ISI). Traditionally, SC-FDMA system decision feedback equalizer (DFE) is often used to eliminate ISI caused by multipath propagation. This article proposes frequency domain turbo equalization based on nonlinear multiuser detection for uplink SFBC SC-FDMA transmission systems. The presented iterative receiver performs equalization with soft decisions feedback for ISI mitigation. Its coefficients are derived using minimum mean squared error criteria. The receiver configuration study is Alamouti's SFBC with two transmit and two receive antennas. New receiver approach is compared with the recently proposed suboptimal linear detector for SFBC SC-FDMA systems. Simulation results confirm that the performance of the proposed iterative detection outperforms conventional detection techniques. After a few iterations, bit-error-rate performance of the proposed receiver design is closely to the matched filter bound.

Channel‐independent 3D‐EXIT chart‐based path scheduling for serially concatenated decoders

“…Consider an Orthogonal Frequency Division Multiplexing-based digital data transmission for a single input single output system. For each subcarrier the system is modeled as, r ¼ hs þ n; (1) where n is a complex Additive White Gaussian Noise (AWGN) with zero mean and variance σ 2 n , and h is the single tap complex channel response at each narrowband subcarrier. The transmitted symbol sϵX is a uniformly distributed, zero mean random variable, X, is a symbol alphabet set with cardinality X j j ¼ M ¼ 2 c and c is the number of bits/symbol.…”

“…Turbo receivers exhibit excellent complexity performance tradeoff and have therefore been incorporated in many current mobile standards . The effectiveness of iterative message passing has been demonstrated for Turbo codes involving an iterative operation of parallel concatenated decoders .…”

Low complexity ordered successive interference cancelation detection algorithm for uplink MIMO SC‐FDMA system

“…Whereas noise amplification, inter symbol interference (ISI), and multiple access interference (MAI) lead to unacceptable BER performance. Furthermore, these detectors are ineffective for fading channels with spectral nulls [12][13][14].…”

“…Non-linear MIMO detection methods include decision feedback equalization (DFE), which performs significantly better than the MMSE/ZF criterion due to its removal of past ISI. But incorrect decision feedback suffers from performance degradation [13,15]. Vertical bell layered (V-BLAST) followed by successive interference cancelation (SIC) algorithm is a better substitute for MMSE/ZF counterpart to combat both MAI and ISI.…”