Single-RF index shift keying aided differential space-time block coding

Abstract

We propose a new single-RF Differential Space-Time Block Coding using Index Shift Keying (DSTBC-ISK), which is the first in the family of Differential Space-Time Modulation (DSTM) schemes that can simultaneously achieve the following three imperative objectives of (1) forming a finite-cardinality transmit-signals set under the matrix multiplications of differential encoding; (2) retaining a single-stream ML detection complexity that does not grow with the constellation size; (3) offering a beneficial transmit diversity gain over the recently developed Differential Spatial Modulation (DSM). In order to make a fair comparison, we also conceive a low-complexity single-stream detector for DSM, which does not impose any performance loss in comparison to the existing solutions in open literature. Furthermore, in order to improve the performance of finite-cardinality DSTM schemes at higher throughputs, we propose to generalize both Differential Amplitude Shift Keying (DASK) and Amplitude Shift Keying (ASK), which form the generic multi-level-ring star QAM constellation that subsumes the existing two/four-level-ring DASK solutions as special cases. Although the DASK approach has been popularly used in DSTM schemes, we demonstrate that our generalized ASK technique achieves a higher capacity and a better performance in channel coding assisted systems. Moreover, since the employment of star QAM constellations imposes the ring-amplitude dependent signal power problem for detection, we further develop bespoke Maximum-Likelihood (ML), Minimum Mean Squared Error (MMSE) and Least Square (LS) detectors for DSTM using DASK/ASK, which exhibit different performance versus complexity tradeoffs. Our simulation results demonstrate that the proposed DSTBC-ISK is capable of achieving substantial diversity gains over DSM without eroding its low transceiver complexity.

More information

Identifiers

ORCID for Chao Xu: orcid.org/0000-0002-8423-0342

ORCID for Rakshith Rajashekar: orcid.org/0000-0002-7688-7539

ORCID for Lajos Hanzo: orcid.org/0000-0002-2636-5214

Catalogue record

Export record

Altmetrics