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In this paper, the end-to-end bit error performance of a dual-hop (DH) energy harvesting (EH) amplify-and-forward/decode-and-forward (AF/DF) system is investigated. In this system, the source communicates with the destination over an intermediate relay when the direct link between the source and the destination is in deep fade. The channels are assumed to be exposed to Nakagami- $m$ fading and all nodes are equipped with one antenna. The relay uses power splitting (PS) and time switching (TS) relaying protocols to harvest energy and uses it to forward the decoded signal or to transmit the amplified version of the received signal to the destination. The bit error probabilities of the considered DH-AF and DH-DF systems are analytically derived for both EH protocols and their performances are comparatively evaluated. Moreover, a system optimization is performed to maximize the bit error rate (BER) performance. For the TS mode, a list of mixture of modulations is provided for different spectral efficiency values and different time allocation parameters. Our comprehensive results on the BER performance of AF- and DF-aided DH networks with EH in the relay, provide basic guidelines for the design of the future DH-EH systems. [ABSTRACT FROM AUTHOR]

In this paper, a bidirectional cognitive cross network using spatial modulation (SM) along with physical-layer network coding (PLNC) is proposed. In our model, a primary user pair located far from each other, exchanges information in the lack of a direct link so that a relay is required for a reliable communication. A secondary user pair shares their relay with the primary user in return for access to the licensed spectrum. Both users exploit SM while the relay also applies PLNC. It is assumed that each user pair can eavesdrop the signal of the other user pair to use these signals as side information and cancel them from the PLNC mapped signal broadcasted by the relay. Optimum power allocation, in which two scenarios are considered, is proposed for sources and the relay. In Scenario 1, the optimization is performed by minimizing the bit error probability (BEP) of the primary user due to its priority in the licensed band. Scenario 2, which minimizes BEP of both users, provides the optimum results for the whole system. A theoretical BEP analysis is performed and the results are supported via computer simulation results, which are in perfect match with theoretical findings. [ABSTRACT FROM AUTHOR]

Successive relaying has recently emerged as an effective technique for cooperative networks and provides significant improvements in bandwidth efficiency over traditional relaying techniques; however, to achieve full-diversity, the available successive relaying protocols generally assume noise-free source-relay and interference-free inter-relay channels. In this paper, a novel successive relaying protocol is proposed for N-relay wireless networks by removing these optimistic assumptions. The proposed protocol benefits from distributed space-time block codes (STBCs) with coordinate interleaving and relay selection. It achieves a diversity order of two and high transmission rate under realistic network conditions with single-symbol maximum likelihood (ML) detection. A general N-relay signaling protocol is presented, and specific design examples are given for N=2, 3 and 4-relay cooperative networks. The average symbol error probability (ASEP) is analytically derived and shown to match with computer simulation results. It is also shown via computer simulations that the proposed scheme achieves significantly better error performance and is more robust to channel estimation errors than its counterparts given in the literature under realistic network conditions. [ABSTRACT FROM AUTHOR]

Presents a study which introduced multilevel coded continuous-phase frequency-shift keying (CPFSK) systems for both additive white Gaussian noise and fading channels. Multilevel coding and multistage decoding techniques of fading channels; Description of set partitioning rules and CPFSK; How computer stimulation results show proposed systems bit-error performance and decoder complexity advantages; Conclusion.

N/A [ABSTRACT FROM AUTHOR]

This work investigates the negative effects of channel estimation errors on the performance of spatial modulation (SM) when operating over flat Rayleigh fading channels. The pairwise error probability of the SM scheme is derived in the presence of channel estimation errors and an upper bound on the average bit error probability is evaluated for M-PSK and M-QAM signalling. It is shown via computer simulations that the derived upper bound becomes very tight with increasing signal-to-noise ratio (SNR) and the SM scheme is quite robust to channel estimation errors. [ABSTRACT FROM PUBLISHER]

Spatial modulation (SM), in which multiple antennas are used to convey information besides the conventional M-ary signal constellations, is a new multiple-input multiple-output (MIMO) transmission technique, which has recently been proposed as an alternative to V-BLAST (vertical Bell Labs layered space-time). In this paper, a novel MIMO transmission scheme, called spatial modulation with trellis coding (SM-TC), is proposed. Similar to the conventional trellis coded modulation (TCM), in this scheme, a trellis encoder and an SM mapper are jointly designed to take advantage of the benefits of both. A soft decision Viterbi decoder, which is fed with the soft information supplied by the optimal SM decoder, is used at the receiver. A pairwise error probability (PEP) upper bound is derived for the SM-TC scheme in uncorrelated quasi-static Rayleigh fading channels. From the PEP upper bound, code design criteria are given and then used to obtain new 4-, 8- and 16-state SM-TC schemes using quadrature phase-shift keying (QPSK) and 8-ary phase-shift keying (8-PSK) modulations for 2,3 and 4 bits/s/Hz spectral efficiencies. It is shown via computer simulations and also supported by a theoretical error performance analysis that the proposed SM-TC schemes achieve significantly better error performance than the classical space-time trellis codes and coded V-BLAST systems at the same spectral efficiency, yet with reduced decoding complexity. [ABSTRACT FROM PUBLISHER]

A novel multiple-input multiple-output (MIMO) transmission scheme, called space-time block coded spatial modulation (STBC-SM), is proposed. It combines spatial modulation (SM) and space-time block coding (STBC) to take advantage of the benefits of both while avoiding their drawbacks. In the STBC-SM scheme, the transmitted information symbols are expanded not only to the space and time domains but also to the spatial (antenna) domain which corresponds to the on/off status of the transmit antennas available at the space domain, and therefore both core STBC and antenna indices carry information. A general technique is presented for the design of the STBC-SM scheme for any number of transmit antennas. Besides the high spectral efficiency advantage provided by the antenna domain, the proposed scheme is also optimized by deriving its diversity and coding gains to exploit the diversity advantage of STBC. A low-complexity maximum likelihood (ML) decoder is given for the new scheme which profits from the orthogonality of the core STBC. The performance advantages of the STBC-SM over simple SM and over V-BLAST are shown by simulation results for various spectral efficiencies and are supported by the derivation of a closed form expression for the union bound on the bit error probability. [ABSTRACT FROM PUBLISHER]