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Spatial modulation (SM) has the potential to meet the requirements of 5G and beyond communication systems with features such as reduced hardware complexity and good trade-off between spectral efficiency and energy efficiency. In this study, an efficient non-square differential spatial modulation (DSM) scheme is presented in which the number of time slots is one more than the number of transmit antennas. The introduced scheme includes one empty time slot. At the other time slots, the time slots of the conventional DSM (CDSM) are used (the Gray code order (GCO) can also be used). There is one active antenna at each time slot of the proposed scheme. The index of empty time slot conveys information. Thus, in comparison with CDSM (or GCO), for the same number of transmit antennas, the introduced scheme has more energy-free bits (index bits). It is free of pilot overhead, channel estimation complexity, and potential channel state information (CSI) estimation errors. Further, a detector with no error propagation is presented. Analytical expressions for the bit error rate (BER) are derived at high signal-to-noise ratios (SNRs) and high SNRs per bit (SNRbs). Simulation results verify the theoretical evaluation and demonstrate the efficiency of the proposed scheme.

Spatial modulation (SM) has the potential to meet the requirements of 5G and beyond communication systems with features such as reduced hardware complexity and good trade-off between spectral efficiency and energy efficiency. In this study, an efficient non-square differential spatial modulation (DSM) scheme is presented in which the number of time slots is one more than the number of transmit antennas. The introduced scheme includes one empty time slot. At the other time slots, the time slots of the conventional DSM (CDSM) are used (the Gray code order (GCO) can also be used). There is one active antenna at each time slot of the proposed scheme. The index of empty time slot conveys information. Thus, in comparison with CDSM (or GCO), for the same number of transmit antennas, the introduced scheme has more energy-free bits (index bits). It is free of pilot overhead, channel estimation complexity, and potential channel state information (CSI) estimation errors. Further, a detector with no error propagation is presented. Analytical expressions for the bit error rate (BER) are derived at high signal-to-noise ratios (SNRs) and high SNRs per bit (SNRbs). Simulation results verify the theoretical evaluation and demonstrate the efficiency of the proposed scheme. [ABSTRACT FROM AUTHOR]

Coded-cooperation combines virtual MIMO transmission and channel coding to achieve forward error correction while achieving diversity gain. It is a promising technology in 5G communications. The polar code is the only channel coding technology that can theoretically achieve Shannon limit transmission, which make it the preferred coding technology in cooperative communication. In this paper, we proposed a new wireless communication scheme, which is a polar coded cooperative spatial modulation schemes based on Plotkin construction and Quasi-uniform puncturing (QUP). First, we adopt Plotkin construction based on the inverted codeword of the polar code to get a cooperation method, which offer a significant improvement in performance on the polar code cooperation under fading channels. We analyze the decoding characteristics of the inverted codewords and then introduces the QUP method to improve the cooperation benefits. At the same time, we extend the cooperation scheme with differential spatial modulation for the proposed coded cooperative schemes. The new coded-cooperation scheme outperforms its coded non-cooperative counterpart schemes under identical conditions, as expected. Monte Carlo simulated results show that the proposed cooperative schemes outperform their corresponding non-cooperative counterpart schemes, by the gain of 2.5 dB with 1024 code length and 0.25 code rate under identical conditions. [ABSTRACT FROM AUTHOR]

Differential spatial modulation uses the antenna index to transmit information, which improves the spectral efficiency, and completely bypasses any channel side information in the recommended setting. A generalized distributed multiple turbo coded-cooperative differential spatial modulation based on distributed multiple turbo code is put forward and its performances in Rayleigh fading channels is analyzed. The generalized distributed multiple turbo coded-cooperative differential spatial modulation scheme is a coded-cooperation communication scheme, in which we proposed a new joint parallel iterative decoding method. Moreover, the code matched interleaver is considered to be the best choice for the generalized multiple turbo coded-cooperative differential spatial modulation schemes, which is the key factor of turbo code. Monte Carlo simulated results show that the proposed cooperative differential spatial modulation scheme is better than the corresponding non-cooperative scheme over Rayleigh fading channels in multiple input and output communication system under the same conditions. In addition, the simulation results show that the code matched interleaver scheme gets a better diversity gain as compared to the random interleaver. [ABSTRACT FROM AUTHOR]

In this paper, the performance of precoding-aided differential spatial modulation (PDSM) systems with optimal transmit antenna subset (TAS) selection is examined analytically. The average bit error rate (ABER) performance of the optimal TAS selection-based PDSM systems using a zero-forcing (ZF) precoder is evaluated using theoretical upper bound and Monte Carlo simulations. Simulation results validate the analysis and demonstrate a performance penalty < 2.6 dB compared with precoding-aided spatial modulation (PSM) with optimal TAS selection. The performance analysis reveals a transmit diversity gain of urn:x-wiley:12256463:media:etr212438:etr212438-math-0001 for the ZF-based PDSM (ZF-PDSM) systems that employ TAS selection with urn:x-wiley:12256463:media:etr212438:etr212438-math-0002 transmit antennas, urn:x-wiley:12256463:media:etr212438:etr212438-math-0003 selected transmit antennas, and urn:x-wiley:12256463:media:etr212438:etr212438-math-0004 receive antennas. It is also shown that reducing the number of activated transmit antennas via optimal TAS selection in the ZF-PDSM systems degrades ABER performance. In addition, the impacts of channel estimation errors on the performance of the ZF-PDSM system with TAS selection are evaluated, and the performance of this system is compared with that of ZF-based PSM with TAS selection.

Differential spatial modulation (DSM) is a multiple input multiple output (MIMO) wireless transmission technique that achieves additional data bit transmission by utilizing antenna activation indexes. Combined with amplitude phase shift keying (APSK) constellations, the spectrum efficiency of DSM system can be further improved. However, the theoretically optimal maximum likelihood (ML) detection suffers from a high complexity that grows exponentially with the number of transmit antennas (TAs). Besides, the imperfect channel state information in fast fading channels leads to a severe deterioration of the detection performance. To address these problems, we propose a novel transmission scheme named reordered amplitude phase shift keying aided differential spatial modulation (RAPSK-DSM) and its low-complexity decision-feedback differential detection (DFDD) based detection algorithm. The proposed RAPSK-DSM scheme provides a better solution for addressing the error propagation problem and its detector utilizes the preceding channel gain vectors from previous detection results to mitigate the performance loss caused by time-selective channel fading. Furthermore, by decomposing and pre-computing the detection process, the complexity of proposed detector is effectively reduced due to the avoidance of redundant computations. Numerical analyses and simulation results show that the proposed RAPSK-DSM system is able to achieve substantial bit error rate (BER) performance improvement under fast fading channel conditions at the expense of low complexity. [ABSTRACT FROM AUTHOR]

In this paper, the performance of precoding‐aided differential spatial modulation (PDSM) systems with optimal transmit antenna subset (TAS) selection is examined analytically. The average bit error rate (ABER) performance of the optimal TAS selection‐based PDSM systems using a zero‐forcing (ZF) precoder is evaluated using theoretical upper bound and Monte Carlo simulations. Simulation results validate the analysis and demonstrate a performance penalty < 2.6 dB compared with precoding‐aided spatial modulation (PSM) with optimal TAS selection. The performance analysis reveals a transmit diversity gain of NT−NR+1 for the ZF‐based PDSM (ZF‐PDSM) systems that employ TAS selection with NT transmit antennas, NS selected transmit antennas, and NR receive antennas. It is also shown that reducing the number of activated transmit antennas via optimal TAS selection in the ZF‐PDSM systems degrades ABER performance. In addition, the impacts of channel estimation errors on the performance of the ZF‐PDSM system with TAS selection are evaluated, and the performance of this system is compared with that of ZF‐based PSM with TAS selection. [ABSTRACT FROM AUTHOR]

Space-time block coded differential spatial modulation (STBC-DSM) is a recently proposed spectral efficient multiple-input-multiple-output (MIMO) transmission technique. Existing detection algorithms for STBC-DSM are designed for quasi-static channels, which limits the application of STBC-DSM in fast fading channels. In this letter, we propose a novel decision-feedback differential detection (DFDD) based detector for STBC-DSM system under fast-fading channels. The proposed detector mitigates the impact of channel vector changes by using the DFDD metric which contains multiple previous detection results. Simulation results show that the proposed detector is more tolerable in time-selective channels than other existing STBC-DSM detectors. [ABSTRACT FROM AUTHOR]

Differential modulation schemes are very relevant in receivers having power and processing limitations, as these schemes dispense with the need for knowledge of channel coefficients for symbol detection. Spatial modulation (SM) is a scheme used in multi-antenna transmission scenarios where the data is transmitted in the amplitude, phase and spatial domains through selected antennas. In the coherent domain, generalized SM (GSM) employs multiple antennas in combination during every time slot to enhance the spectral efficiency (SE). In this paper, we propose two differential schemes which activate two or more antennas at a time to transmit the modulated symbol. These schemes achieve higher SE using a lesser number of antennas and lower order modulation schemes instead of the higher number of antennas required for conventional SM schemes based on differential modulation. Simulation studies reveal that the proposed schemes have better bit error rate performance than traditional differential SM schemes. We also derive the analytical union bound for the proposed schemes and is satisfied from medium to high signal-to-noise ratio (SNR) ranges. [ABSTRACT FROM AUTHOR]

Diversity is a fundamental concept used to reduce the adverse effects of fading in wireless communications. Differential full diversity spatial modulation (DFD-SM) is a differential spatial modulation (DSM) scheme that makes use of a cyclic signaling phase shift keying (PSK) constellation to achieve transmit diversity. In this paper, firstly, we extend the work of DFD-SM to improve its throughput and/or error performance, by making use of an amplitude phase shift keying (APSK) constellation. Next, a power allocation concept(PAC) based on generalized differential modulation (GDM) is applied to DFD-SM using APSK. Finally we derive a theoretical upper bound on the average bit error probability (ABEP) for DFD-SM using APSK. It is shown through Monte Carlo simulations that the proposed DFD-SM using APSK scheme outperforms conventional DFD-SM by approximately 1 dB at the same throughput, and that the proposed power allocation scheme provides an approximate 3 dB gain over the conventional scheme.

Differential full diversity spatial modulation (DFD-SM) is a differential spatial modulation scheme that makes use of a cyclic unitary M-ary phase shift keying (M-PSK) constellation to achieve diversity gains at both the transmitter and receiver. In this paper, we extend the power allocation concept of generalized differential modulation (GDM) to DFD-SM to improve its block-error rate (BLER). A novel power allocation scheme is formulated, and its optimum power allocation is derived. An asymptotic upper bound is presented for the new scheme and results are verified through Monte Carlo simulations. It can be seen that for a large enough frame length, the proposed scheme can almost achieve coherent performance. We also propose a low complexity detection scheme for DFD-SM. We evaluate the computational complexity of the maximum-likelihood (ML) detector and compare it to that of the proposed algorithm. It is shown that our scheme is independent of the constellation size. Numerical simulations of the BLER are presented, and it can be seen that the proposed scheme provides near ML performance throughout the entire signal-to-noise ratio (SNR) range with a complexity reduction of about 55% and 52% for one and two receive antennas respectively, in the high SNR region.

In this paper, a novel scheme dubbed space-time block coded rectangular differential spatial modulation (STBC-RDSM) is proposed for multiple-input and multiple-out (MIMO) systems, which combines space-time block coding (STBC) and rectangular differential spatial modulation (RDSM) to reap their respective benefits while avoiding the drawbacks of conventional differential spatial modulation (DSM) systems. More specifically, in the proposed STBC-RDSM scheme, information bits are conveyed via the rectangular differentially encoded antenna index matrices, as well as the STBC blocks. Furthermore, a low-complexity detection scheme is proposed. Our simulation results demonstrate that STBC-RDSM outperforms its conventional DSM counterparts in various spectral efficiencies. Finally, a closed-form union bound on the bit error rate (BER) is derived and validated by our simulation results. [ABSTRACT FROM AUTHOR]

In this paper, a novel multiple-input multiple-output (MIMO) transmission scheme termed space-time block coded differential spatial modulation (STBC-DSM) is proposed. It employs the hybrid concept of differential spatial modulation (DSM) and space-time block coding (STBC) to exploit the diversity benefits of STBC without the channel state information (CSI). In the STBC-DSM scheme, information bits are conveyed via the antenna matrix (AM) indices, as well as STBC blocks. Specifically, a novel AM set is first designed such that the transmitter requires only sparse (one or two) frequency radio (RF) chains. Then, the proposed STBC-DSM scheme is extended to the large-scale MIMO scenarios, and a low-complexity near-optimal detection algorithm is developed. Finally, an upper bound for the average bit error probability of the proposed scheme is derived. Both analytical and simulation results have shown that the proposed scheme is capable of achieving considerable performance gains over the existing DSM and differential Alamouti schemes. [ABSTRACT FROM PUBLISHER]

Differential full diversity spatial modulation (DFD-SM) is a differential spatial modulation (DSM) scheme that makes use of a cyclic unitary M-ary phase shift keying (M-PSK) constellation to achieve diversity gains at both the transmitter and receiver. In this paper, we extend the power allocation concept of generalized differential modulation (GDM) to DFD-SM to improve its block error rate (BLER). A novel power allocation scheme is formulated, and its optimum power allocation is derived. An asymptotic upper bound is presented for the new scheme and results are verified through Monte Carlo simulations. It can be seen that for a large enough frame length, the proposed scheme can almost achieve coherent performance. We also propose a low complexity detection scheme for DFD-SM. We evaluate the computational complexity of the maximum-likelihood (ML) detector and compare it to that of the proposed algorithm. It is shown that our scheme is independent of the constellation size. Numerical simulations of the BLER are presented, and it can be seen that the proposed scheme provides nearML performance throughout the entire signal-to-noise ratio (SNR) range with a complexity reduction of about 55 % and 52 % for one and two receive antennas respectively, in the high SNR region. [ABSTRACT FROM AUTHOR]

We consider differential spatial modulation (DSM) operating in a block fading environment and propose sparse unitary dispersion matrices (DMs) using algebraic field extensions. The proposed DM sets are capable of exploiting full transmit diversity and, in contrast to the existing schemes, can be constructed for systems having an arbitrary number of transmit antennas. More specifically, two schemes are proposed: 1) field-extension-based DSM (FE-DSM), where only a single conventional symbol is transmitted per space–time block; and 2) FE-DSM striking a diversity–rate tradeoff (FE-DSM-DR), where multiple symbols are transmitted in each space–time block at the cost of a reduced transmit diversity gain. Furthermore, the FE-DSM scheme is analytically shown to achieve full transmit diversity, and both proposed schemes are shown to impose decoding complexity, which is independent of the size of the signal set. It is observed from our simulation results that the proposed FE-DSM scheme suffers no performance loss compared with the existing DM-based DSM (DM-DSM) scheme, whereas FE-DSM-DR is observed to give a better bit-error-ratio performance at higher data rates than its DM-DSM counterpart. Specifically, at data rates of 2.25 and 2.75 bits per channel use, FE-DSM-DR is observed to achieve about 1- and 2-dB signal-to-noise ratio (SNR) gain with respect to its DM-DSM counterpart. [ABSTRACT FROM PUBLISHER]

Differential spatial modulation (DSM) is a novel multiple-input multiple-output wireless transmission technique, which relies on a single radio-frequency transmit structure without the need of the channel state information. In this letter, a novel high-rate design scheme relying on the amplitude phase shift keying (APSK) is proposed for DSM schemes. Moreover, a simplified upper bound of the average bit error probability (ABEP) of the proposed APSK-aided DSM scheme is derived and the ring ratio of the designed DSM constellation is optimized based on our theoretical ABEP results. Simulation results show that, at the same throughputs, the proposed scheme is capable of providing considerable bit error rate performance improvement over conventional DSM schemes. [ABSTRACT FROM PUBLISHER]

Differential spatial modulation (DSM), which does not require the channel state information at the receiver, is an attractive alternative to its coherent counterpart. The optimal maximum-likelihood (ML) detector of the DSM system employs the classic block-by-block method for jointly detecting the activated antenna matrix (AM) and the modulation symbols, resulting in high computational complexity. In this letter, a low-complexity near-ML detector, which operates on a symbol-by-symbol basis, is proposed for the DSM scheme. Specifically, in each block, the index of the activated transmit antenna and modulation symbol in each time slot are first obtained, and then, these antenna indices are utilized to simply determine the index of the activated AM. Simulation results show that the proposed algorithm is capable of offering almost the same performance as that of the ML detector with more than 90% reduction in complexity. [ABSTRACT FROM PUBLISHER]