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This paper discusses layered baud‐space modulation system under arbitrary spatial correlation both at the transmitter and the receiver. Layered baud‐space modulation provides better reliability in spatial modulation systems as well as flexibility in data rates compared to multiple‐active space modulation. Several transmissions occur asynchronously within the time slot. As a result, fractional sampling is employed at the receiver to detect the signals. For this scheme, it is more practical to analyse spatial correlation both at the transmitter and the receiver, since temporal correlation is a likely occurrence. However, asynchronous transmission will lead to higher probability of packet drops when synchronization errors are present. Lower bounds of bit error rates are derived from theoretical criteria based on mutual information and sample covariance of the joint spatial and modulation space. Analytical results for bit error probability are tightly verified from simulations. The channel is assumed to be of frequency‐flat Rayleigh fading form. The tests are carried out under different antenna spacing, amplitude and phase modulation schemes and various number of transmit and receive antenna configurations. [ABSTRACT FROM AUTHOR]

We present a well-known generalized Reed–Solomon (GRS) code incorporated with space-time block coded spatial modulation (STBC-SM) for wireless networks, which is capable of enjoying coded cooperation between the source and the relay. In the proposed distributed GRS-coded STBC-SM (DGRSC-STBC-SM) scheme, the source and relay nodes use distinct GRS codes. At the relay, we employ the concept of information selection to choose the message symbols from the source for further encoding. Thus, the codewords jointly constructed by the source and relay are generated at the destination. For achieving the best codeword set at the destination, we propose an optimal algorithm at the relay to select partial symbols from the source. To reduce the computational complexity, we propose a more practical algorithm with low complexity. Monte Carlo simulation results show that the proposed scheme using the low-complexity algorithm can achieve near-optimal error performance. Furthermore, our proposed scheme provides better error performance than its corresponding coded non-cooperative counterpart and the existing Reed–Solomon coded cooperative SM (RSCC-SM) scheme under identical conditions. [ABSTRACT FROM AUTHOR]

Summary: Conventional‐generalized spatial modulation (C‐GSM) is an NT×NR multiple‐input multiple‐output (MIMO) spatial modulation (SM) scheme that transmits the same complex amplitude/phase modulation symbol from multiple active transmit antennas. By using two active transmit antennas during a transmission interval, C‐GSM is capable of achieving high spectral efficiencies. However, as the size of the signal constellation/domain increases, the minimum Euclidean distances (ED) between the symbols decrease. Hence, this leads to a degradation of the average bit error rate (ABER) performance of the scheme. Hence, motivated to improve the error performance of C‐GSM schemes, first, this study proposes a new scheme called Golden codeword‐based generalized spatial modulation (GCW‐GSM), which combines C‐GSM and the Golden code to take advantage of the benefits of both while avoiding their drawbacks. The proposed scheme uses conventional quadrature amplitude modulation (C‐QAM), and it is investigated over Rayleigh frequency‐flat fading channels with additive white Gaussian noise. Second, a closed‐form expression of the theoretical average bit error probability of the proposed GCW‐GSM scheme is formulated. Compared to simulation results, it proves to be increasingly tight at high signal‐to‐noise ratio values. Finally, the proposed scheme performance over the Rayleigh‐frequency‐flat fading channel is compared to that over the Rician channel. An improvement in the error performance of 6dB with spectral efficiency of 10bits/s/Hz is seen in 4×4 C‐16QAM GCW‐GSM over 4×4 C‐256QAM conventional‐spatial modulation and 4×4 C‐256QAM C‐GSM schemes at a bit error rate (BER) of 1×10−5. The 4×4 C‐16QAM GCW‐GSM scheme exhibits an improvement in the error performance of 2.9dB with spectral efficiency of 10bits/s/Hz over the 4×4 C‐64QAM conventional quadrature spatial modulation scheme at a BER of 1×10−5. Finally, the 4×4 16‐QAM GCW‐GSM under Rayleigh fading has a performance gain of 3 dB over 4×4 16‐QAM GCW‐GSM under Rician fading with a Rician K factor of 3. [ABSTRACT FROM AUTHOR]

Summary: The receiver of a conventional differential modulation scheme performs detection without knowledge of the channel state information (CSI). This results in a 3 dB performance loss compared to coherent modulation. In order to enhance this error performance, generalised differential modulation is utilised. This paper extends the generalised differential modulation scheme to multiple‐input symbol Golden code (MIS‐GC) and proposes a multiple‐input symbol generalised differential Golden code (MIS‐GD‐GC) scheme. This scheme improves the error performance when compared to conventional differential MIS‐GC and achieves a diversity order of 2lNr compared to the conventional Golden code, where l ≥ 1 is an integer, Nr is the number of receive antennas and 2l represents the number of multiple‐input symbols in the MIS‐GC system. We also derive the average bit error probability for the MIS‐GD‐GC scheme. The simulations of bit error rate (BER) compare very well to the derived theoretical bounds and show that the BER of MIS‐GD‐GC draws closer to that of coherent MIS‐GC as the frame length increases. For instance, at a frame length of B=400, the error performance gap between MIS‐GD‐GC and its coherent counterpart is only 0.4 dB. [ABSTRACT FROM AUTHOR]

A Plotkin based polar coded orthogonal frequency division multiplexing (OFDM) with multiple input and multiple output (MIMO) antennas scheme is proposed and its performance over frequency selective Rayleigh fading channel has been evaluated. In the considered Plotkins construction, the longer length code word is formed on the basis of two shorter length code words. Due to the presence of a parallel split in the design of the considered Plotkins construction, the proposed scheme is efficiently extended to coded cooperative scenarios. As the relay always plays crucial role in the design of cooperative communication system, therefore an intelligent criteria for the selection of information bits is employed at the relay node. To check the efficacy and to maintain the complete fairness in the performance of the proposed coded cooperative scheme, the authors have also developed the traditional nested polar coded cooperative scheme in the context of OFDM with MIMO antennas. The Monte Carlo simulated bit error rate (BER) performance revealed that the proposed coded cooperative scheme outperforms the traditional nested polar coded cooperative OFDM with MIMO antennas scheme by gain of 0.5∼0.6 dBs. This significant gain in BER performance of the proposed coded cooperative scheme is made possible due to the efficient selection criteria and the joint successive cancellation (SC) decoding tecnique employed at relay node and at the destination node, respectively. Moreover, the proposed coded cooperative scheme outperforms its corresponding coded non-cooperative counterpart scheme by roughly a gain of 1 dB under identical conditions. [ABSTRACT FROM AUTHOR]

Summary: The Alamouti space‐time block code (STBC) achieves full diversity gain at a rate of 1/2. However, the Alamouti scheme does not provide multiplexing gain. The Silver code offers both diversity and multiplexing gain. It has a minimum normalization determinant of 1/7. The Golden code is another STBC that offers both diversity and multiplexing gain. The Golden code is ranked higher than the Silver code because of its lower minimum normalization determinant of 1/5, however, the golden code suffers from a high detection complexity in the modulation order of M4. The 3/4‐Sezginer code is another STBC, which compromises between the Alamouti scheme and the Golden code in terms of diversity gain and multiplexing gain. The 3/4‐Sezginer code achieves full diversity and half of multiplexing gain. The uncoded space‐time labeling diversity (USTLD) is a recent scheme that improves the error performance when applied to the STBC in multiple‐input multiple‐output (MIMO) systems and will be applied to the 3/4‐Sezginer STBC to improve the error performance in this paper. The theoretical error probability for both the 3/4‐Sezginer STBC and the improved system is formulated using the union bound in this paper. The theoretical error probabilities of both 16‐QAM and 64‐QAM are validated through Monte Carlo simulation. The simulation and theoretical results show that the proposed system with 4 NR can achieve an SNR gain of 1 dB for 16‐QAM and 1.2 dB 64‐QAM at a bit error rate (BER) of 10−6. [ABSTRACT FROM AUTHOR]