High-rate Space-Time-Frequency Codes Achieving Full-Diversity with Partial Interference Cancellation Group Decoding

TL;DR

This paper introduces a high-rate space-time-frequency code design for OFDM systems that achieves full diversity with low decoding complexity using partial interference cancellation group decoding, balancing rate, performance, and complexity.

Contribution

It proposes a novel STF code design with a grouping scheme enabling full diversity and high data rate under PIC group decoding in frequency-selective channels.

Findings

Achieves full diversity with low decoding complexity.

Maintains high data rate while ensuring full diversity.

Effective for any number of OFDM sub-carriers.

Abstract

The partial interference cancellation (PIC) group decoding has recently been proposed to deal with the decoding complexity and code rate trade-off on the basis of space-time block code (STBC) design criterion when full diversity is achieved. It provides a framework to arrange the rate-complexity-performance tradeoff by choosing a suitable size of information symbol groups. In this paper, a simple design of a linear dispersive space-time-frequency (STF) code is proposed with a design criterion to achieve high rate for frequency-selective channels in terms of multipath when the PIC group decoding is applied at receiver. With an appropriate grouping scheme as well as the PIC group decoding, the proposed STF code is shown to obtain the similar diversity gain as the maximum likelihood (ML) decoding, namely full-dimensional sphere decoding, but have a low decoding complexity. It seems as an intermediate decoding between the ML receiver and zero-forcing (ZF) receiver. The proposed grouping design criterion for the PIC group decoding to achieve full diversity deploying the orthogonal-frequency-division multiplexing (OFDM) technique is also an intermediate condition between the loosest ML full rank criterion of codewords and the strongest ZF linear independence condition of the column vectors for the equivalent frequency-selective channel matrix. It can achieves full diversity with the PIC group decoding for any number of sub-carriers and the data rate can be made high. Several code design examples are illustrated for the feasibility of this coding scheme. Simulation results show that the proposed STF code can well address the rate-performance-complexity tradeoff of the multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) communication system.