Cooperative Time Successive SSK-M-ary Modulation for Decode-and-Forward Relay Systems

Space shift keying (SSK) is a single radio frequency (RF) chain multiple-input multiple-output (MIMO) scheme which uses the indices of transmit antennas for information transmission. Time successive SSK-M-ary modulation (TSSM) is a second order transmit diversity scheme based on single RF chain multiple antenna transmitter. In this letter, TSSM based on selection combining (TSSM-SC) is conceived to realize a single RF chain receiver for TSSM without compromise on the diversity order. The metric of receiver antenna selection is proposed for TSSM-SC. A novel approach is given to find a tight upper bound on the bit error rate (BER) of TSSM-SC in simple closed form. Further, the diversity order of TSSM-SC is analyzed with asymptotic expression. Simulation results that validate the analyses are given to show the diversity gain at reduced receiver complexity. The performance of TSSM-SC is compared with other schemes with selection combining to highlight its performance advantage.

Space shift keying (SSK) is a recent multiple-input multiple-output (MIMO) modulation scheme where information is conveyed by the index of the activated antenna. An advantage of SSK transmitter is that it requires only one radio frequency (RF) chain. To achieve transmit diversity in such a single RF chain two antenna transmitter, modulation is dynamically changed between SSK and a modified form of binary phase shift keying (BPSK) based on channel condition in dynamic SSK-BPSK (DSB). DSB achieves second-order transmit diversity which is attributed to the statistical independence of sum and difference of independent and identically distributed complex Gaussian channel vectors. In order to study the impact of correlated and nonidentically distributed channel vectors on the transmit diversity of DSB, we consider transmitter correlated nonidentical Rayleigh fading in this work. We derive the bit error rate (BER) expression of DSB and the probability of using BPSK in DSB for the considered fading channel. Using asymptotic BER expressions, we study the diversity order of DSB. Results show that the transmit diversity of DSB is unaffected by the transmitter correlation when channel fading is identical, but nonidentical fading affects transmit diversity. Finally, we corroborate our analyses with simulation results.

In this letter, we consider an $N_{r} \times N_{t}$ multiple-input–multiple-output system in which $M$ -ary phase shift keying (MPSK) and space shift keying (SSK) are used in successive time slots. We call this system time successive SSK-MPSK (TSSM), and we show that this system achieves a transmit diversity order of 2. In TSSM, during the first time slot, information is transmitted with MPSK symbols using all $N_t$ transmitter antennas, with each antenna using $N_{t}^{\textrm{th}}$ of the total transmitter power. During the second time slot, SSK modulation is used to transmit the same information. We further derive the optimal detection criterion, pairwise error probability, and the average union bound of the bit error rate (BER) of TSSM. We show the diversity order using asymptotic approximation of the average union bound of the BER of TSSM. We compare the BER of TSSM with that of time orthogonal signal design assisted SSK, coherent space time shift keying, and other schemes. The simulation results show that TSSM performs considerably better.

Space shift keying (SSK) is a special case of spatial modulation (SM), which is a relatively new modulation technique that is getting recognized to be attractive in multi-antenna communications. Our new contribution in this paper is an analytical derivation of exact closed-form expression for the end-to-end bit error rate (BER) performance of SSK in decode-and-forward (DF) cooperative relaying. An incremental relaying (IR) scheme with selection combining (SC) at the destination is considered. In SSK, since the information is carried by the transmit antenna index, traditional selection combining methods based on instantaneous SNRs can not be directly used. To overcome this problem, we propose to do selection between direct and relayed paths based on the Euclidean distance between columns of the channel matrix. With this selection metric, an exact analytical expression for the end-to-end BER is derived in closed-form. Analytical results are shown to match with simulation results.

Hardware designs for variant receive space modulation techniques (RSMTs) containing a reduced number of hardware components are proposed in this study. RSMTs rely on precoding of transmitted signals through channel knowledge at the transmitter to spatially modulate the receive antennas. As such, certain receive antennas will only receive messages while all other antennas will not receive any signal. It has been debated in literature that different RSMTs can be designed with single radio frequency (RF) chain receiver. Yet, practical designs are not yet available in literature. In this paper, a family of receiver designs for RSMTs based on commercial off‐the‐shelf components (COTS) are proposed and analyzed. Average error probability, power consumption, cost, and receiver complexity of the different techniques are presented and discussed. Additionally, Simulink models for all these systems are developed and presented. It is revealed that all RSMTs, in fact, do not require more than a single RF chain receiver or in some cases no RF chain, just by utilizing COTS components.

We consider a decode-and-forward (DF) cooperative relaying system where a source (S) and a single relay (R) use space shift keying (SSK) modulation for information transmission to the destination (D). Using the Euclidean distance between the SSK constellation points in the SD and RD links as the selection metric, selection combining (SC) can be used at D. Instead of SC, in order to take into account the average performance of SRD and SD links in the selection, scaled selection combining (SSC) is performed at D such that the selection metric in RD link is scaled by a factor $\alpha$ . The error performance of SSK DF SSC cooperative relaying is analyzed in this work. We derive the end-to-end symbol error probability (SEP) expression of the system in closed-form for binary SSK modulation and verify the results with simulation. Further we infer that SSK DF SSC system performs better than SSK system without cooperative relaying and SC in SSK DF cooperative relaying.

Space Shift Keying (SSK) is a multiple-input multiple-output technique that has drawn more attention in recent years because of its low complex transceiver design. In this paper, an investigation on the Symbol Error Probability (SEP) performance of SSK in a Decode-and-Forward (DF) cooperative relaying system is done. The DF cooperative relaying scenario considers an origin node, an intermediate node and an end node with a direct link between origin and end node, and an indirect link between origin to the intermediate node and intermediate to end node. The SSK modulation is considered at the origin and intermediate nodes with Full Euclidean Distance based Selection Combining (FED-SC) employed at the end node for SSK symbol detection. The SEP expression of the SSK FED-SC in the DF cooperative relaying scheme is derived using the Order Statistics Approach (OSA). Further, a closed-form SEP expression is obtained using a Combined Order Statistics Approach (COSA) considering the number of receive antennas at the intermediate node is equal to the number of receive antennas at the end node. In addition, the closed-form asymptotic SEP expression is presented to evaluate the diversity order of the system. The SEP expressions derived through OSA and COSA are verified using the Monte Carlo simulations. The simulation results revealed that the proposed SSK FED-SC outperforms all the existing SSK DF cooperative selection combining schemes.

In this letter, we propose a cooperative multiple-input multiple-output (MIMO) scheme combining transmit antenna selection (TAS) and space shift keying (SSK). In this scheme, source transmit antennas are selected and SSK is applied by using the selected antennas. Besides the direct link transmission, the relays, that decode the source signal correctly, take part in the transmission. Exact expressions and a considerably accurate approximate expression for the symbol error rate of the proposed SSK system are derived. It is shown that the proposed scheme outperforms the SSK system without TAS and also the conventional cooperative MIMO system, which employs source TAS, at practical signal-to-noise ratio values for especially high data rates and sufficient number of receive antennas at the destination.

Multiple Input Multiple Output (MIMO) systems with limited Radio Frequency (RF) chains play a pivotal role in the Fifth Generation (5G) of wireless networks. However, the transmitter of Generalized Spatial Modulation MIMO (GSM-MIMO) systems that characterized by a single RF chain and multiple active antennas is capable of reducing both the energy consumption and the transmitter cost. In this paper, combining GSM-MIMO systems with the fully digital Geometric Mean Decomposition (GMD)-based precoding scheme and Analog Beamforming (ABF) into Hybrid Beamforming (HBF) regime is presented for Millimeter-wave (mmWave) massive MIMO systems which is a key enabler for 5G networks. In addition, applying the norm-based user selection algorithm in GSM-MIMO scheme with GMD-based hybrid precoding is proposed, and referred to as Multiuser Steered GSM-MIMO (MUS-GSM-MIMO) scheme. Simulation results demonstrate that the proposed schemes are capable of achieving considerable performance gains over the conventional GSM-MIMO schemes, while avoiding the overwhelming costs of multiple RF chains. Therefore, the proposed schemes are very efficient and highly suitable for large-scale and 5G wireless networks.

Rapidly growing demand for high data rates in wireless communication systems is the cause of the merging of Multiple Input Multiple Output (MIMO) and Orthogonal Frequency Division Multiplexing (OFDM) techniques. MIMO-OFDM technique needs Radio Frequency (RF) front end in each antenna, which is not effective for large dimensional antenna size. Therefore, RF front end on the receiver side will be simplified using a single RF technique based on the Electrically Steerable Parasitic Array Radiator (ESPAR) antenna. In real life, a channel cannot be ideal. Therefore, before the signal is transmitted, that signal must be coded to minimized errors when the data transmission process. Convolutional code is a coding technique that can detect and correct error bit (error control coding) and that it is expected to reduce the quantity of Bit Error Rate (BER). In this research, a simulation is designed to analyze single RF performance on the MIMO-OFDM system using Vertical Bell Laboratories Space-Time (VBLAST) detection for convolutional code encoder and Viterbi decoder. The result simulation shows that the channel estimation technique works well on the MIMO-OFDM system using single RF, which is shown in the magnitude and phase curves against the subcarrier index between the theory channel and the estimated channel are at almost the same points. VBLAST-ZF detector performance is shown in the BER curve against SNR, where the difference BER value for SNR value 10 dB between the theory channel and the estimated channel is 0.001499. Channel coding technique using convolutional code encoder and Viterbi decoder with a rate of ½ works well on the MIMO-OFDM system using single RF which is shown in the BER curve against SNR, where BER value with coding technique is smaller than BER value without coding technique.

최근 대용량, 초고속 통신 서비스의 비중이 높아짐에 따라 배열 안테나를 사용하는 MIMO(Multi-Input Multi-Output) 시스템의 활용이 중요하게 평가되고 있다. 하지만 기존의 MIMO 시스템은 다수의 안테나를 사용하기 때문에 안테나의 개수만큼 RF(Radio Frequency) 체인이 요구되며, 이로 인해 복잡도와 전력 소모가 크다는 단점을 가진다. 이러한 기존 MIMO 시스템의 단점을 해결하기 위해서 단일 능동 소자와 다수의 기생 소자를 이용하는 방식의 ESPAR(Electronically Steerable Parasitic Array Radiator) 안테나를 사용하는 빔 공간 MIMO 시스템에 대한 연구가 활발히 진행되고 있다. ESPAR 안테나를 사용하는 빔 공간 MIMO 시스템은 단일 RF 체인으로 구성되어 있기 때문에 기존 MIMO 시스템의 단점을 해결할 수 있다. 본 논문에서는 시스템의 보안성을 향상시키기 위해 QPSK(Quadrature Phase Shift Keying) 변조 방식의 ESPAR 안테나를 사용하는 빔 공간 MIMO 시스템에 비예측성, 비주기성, 구현의 용이성, 민감한 초기조건 등의 특징을 가지고 있는 카오스 통신 알고리즘을 적용하여 QPSK 변조 방식의 ESPAR 안테나를 사용하는 카오스 빔 공간 MIMO 시스템을 구성하고 성능을 평가한다. Recently, utilization of MIMO(Multi-Input Multi-Output) system using array antennas is evaluated significantly according to the extension of high-capacity and high-speed communication services. However, MIMO system has disadvantages such as high-complexity and high-power-consumption, because RF(Radio Frequency) chain is required as antenna number, and several array antenna is used in conventional MIMO system. In order to solve these problems, research about beamspace MIMO system using ESPAR(Electronically Steerable Parasitic Array Radiator) antenna that has single RF chain by using one active antenna and several parasitic elements has been studied actively. Beamspace MIMO system using ESPAR antenna is possible to solve the problems of conventional MIMO system, because this system is composed by single RF chain. In this paper, in order to improve the system security, chaos communication algorithm that has characteristics such as non-periodic, non-predictability, easy implementation and initial condition is applied to QPSK (Quadrature Phase Shift Keying) modulated beamspace MIMO system. We design the chaos QPSK modulated beamspace MIMO system, and evaluate SER performance of this system.

Visible light communication (VLC) is considered a breakthrough wireless communication technology that has been proven capable of achieving very high data rates. This is a key advantage in indoor communication scenarios, since the vast majority of wireless traffic is witnessed in indoor communications. In every wireless system, the trade-off between achievable throughput, transmit signal power and corresponding error rate performance is largely dependent upon the considered modulation format. This is also the case in VLC systems, which are typically characterized by stringent performance requirements. Motivated by this, in the present contribution we introduce the space shift keying (SSK) modulation scheme in the context of non-orthogonal-multiple-access (NOMA) communications, which have been shown to be a performance enhancer of indoor based VLC systems. Based on this, all network users in the considered set up receive the same superimposed signal of all NOMA users, which is transmitted from the activated transmitters corresponding to the multiplexed SSK users information. Based on this and assuming a unique maximum likelihood detection, we quantity the system performance in terms of the corresponding bit error rate (BER) performance at each receiver. This analysis leads to the development of useful insights of theoretical and practical interest, which are expected to be useful in the effective design, implementation and deployment of SSK in NOMA based VLC systems.

In this paper, we present a modulation scheme called generalized symbol sequence modulation (GSSM), which incorporates multiple symbol sequence modulation mappers. In GSSM, additional information is conveyed through symbol sequences from different symbol constellations to increase data rates. In order to convey information, the sequence of symbols is used in three time slots; therefore, a single antenna can convey at least four bits. Unlike spatial modulation (SM), GSSM conveys information over fading and non‐fading channels. The performance of the GSSM system has been validated through bit error rate (BER) simulations and theoretical framework based on various receiving antennas and fading channels. Furthermore, in terms of secrecy rate, it is superior to conventional single input, multiple output systems (SIMO), space shift keying (SSK), and symbol sequence modulation (SSM). Also, GSSM has shown a reduction in receiver computational complexity when compared to SM at the same bit rate. BER results are presented for non‐fading, fading, correlated, and non‐correlated scenarios, under GSSM.

In this paper, we derive the upper bound of bit‐error rate (BER) performance and diversity gain for a decode‐and‐forward (DF) cooperative system. Either maximal‐ratio combining (MRC) or cooperative MRC (C‐MRC) is employed at the receiver in the presence of independent, non‐identical Nakagami‐m fading. Both analytical and simulation results show that C‐MRC takes advantage of spatial diversity more efficiently and thus achieves the same or better performance and diversity order as compared to MRC. Copyright © 2009 John Wiley & Sons, Ltd.

In this paper, we propose a parallel concatenated index modulation and M-ary phase shift keying (MPSK) to integrate with carrier interferometry (CI) codes into the orthogonal frequency division multiplex (OFDM) differential chaotic shift keying (DCSK) communication system. Our objective is to meet different quality of service (QoS) user demands while achieving higher energy efficiency and retaining reliable communications with low peak-to-average power ratio (PAPR). In our design, one input bit set is modulated by the index of the CI codes matrix whose rows are rotated circularly, another bit set is mapped to the MPSK symbols to realize the M-ary modulation. Subsequently, the resultant MPSK symbols are modulated by reference chaotic sequences and spread by the information-bearing rotated CI codes matrix at the transmitter. After the OFDM modulations, the information bearing symbols are transmitted over multiple subcarriers. At the receiver, after the non-coherent chaotic correlation demodulation, the maximum likelihood detection method is firstly applied to attain the estimates of the index modulated bit set, which are then used to recover the phases of chaotic sequences for further evaluation of another MPSK modulated symbols. Since no additional energy is required while more bits can be transmitted via the M-ary modulation and index modulation, the energy efficiency can be improved. In addition, thanks to the orthogonality of the CI codes matrix and the spreading in the frequency domain, the PAPR could be suppressed and reliability performances can be improved. Then theoretical analysis is conducted and simulation results validate the theoretical analysis. Moreover, the results demonstrate the superior bit error rate (BER) performances to benchmarks and flexible data rate could be provided for user terminals via different combinations of the index modulation and the M-ary modulation.