Differential Space-Time Coding Dispensing With Channel Estimation Approaches the Performance of Its Coherent Counterpart in the Open-Loop Massive MIMO-OFDM Downlink

Abstract

In this paper, we propose a simple yet powerful mapping scheme that converts any conventional square-matrix-based differential space-time coding (DSTC) into a nonsquare-matrixbased DSTC. This allows DSTC schemes to be used practically in open-loop large-scale multiple-input multiple-output scenarios. Our proposed scheme may be viewed as the differential counterpart of coherent spatial modulation (SM), of the generalized SM, of Bell laboratories layered space-time architecture, and of subcarrier-index modulation. The fundamental impediment of the existing DSTC schemes is the excessive complexity imposed by the unitary constraint. Specifically, the transmission rate of conventional DSTC schemes decays as the number of transmit antennas increases. Our proposed scheme eliminates this impediment and thus achieves a significantly higher transmission rate. We introduce four novel construction methods for the nonsquare codewords, some of which include an arbitrary number of nonzero elements in each codeword column. Our analysis shows that the proposed encoding technique reduces the complexity of both the inverse Fourier transform and of the detection processes. Our proposed scheme is shown to approach the performance of its coherent counterpart for low-mobility scenarios, where the number of transmit antennas is increased up to 256.

Compressive Sensing Assisted Generalized Quadrature Spatial Modulation for Massive MIMO Systems

“…For the case of 2 RF chains, observe from Fig. 12 (a) that the proposed G-QSM system is capable of outperforming the VBLAST system 4 by 17 dB and 24 dB at 16 bpcu and 22 bpcu respectively at BER=10 −5 at the cost of an extra channel estimation action, which will be eliminated in our future research by conceiving noncoherent detection at 3 dB performance loss [41]. A similar trend can be observed for the case of 4 RF chains in Fig.…”

Rectangular Differential OFDM with Index Modulation

“…In order to improve the transmit rate of conventional DSM [28]- [33], a Rectangular DSM (R-DSM) scheme [36] was proposed for massive MIMO down link communication, which has the same transmit rate as the classic SM scheme and outperforms the existing DSM schemes [28]- [33]. Furthermore, this differential scheme has been applied into the MIMO-STBC [37] and MIMO-OFDM communication scenarios [38]. However, to the best of the authors' knowledge, how to apply the rectangular differential scheme into OFDM-IM system has not been investigated.…”

A Compressive Sensing Assisted Massive SM-VBLAST System: Error Probability and Capacity Analysis

“…The optimal thresholds are selected based on Table II. The theoretical ABEPs of ML detectors are calculated by (32). Moreover, both the OMP and CoSaMP detectors have been employed in our proposed detector for comparison, called ECM-OMP and ECM-CoSaMP detectors, respectively.…”

“…Furthermore, assuming that (25), (27), (29) and (31) can be further simplified as (32). According to (32), the closed form of the ABEP upper bound is given by (11).…”