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.

In this study, the authors propose novel cooperative spatial modulation (SM) systems with two main relaying techniques [amplify‐and‐forward (AF) and decode‐and‐forward (DF)], where all nodes have multiple transmit and/or receive antennas. Most of the studies in the literature of cooperative SM systems, which combine the advantages of cooperative communications and SM systems, consider only the space shift keying (SK) scheme with single receive/transmit antenna at relay and destination. Since the error performance of SM highly depends on the number of receive antennas and more flexible cooperative communications systems can be obtained by using SM with multiple antennas, it is essential to investigate multi‐antenna cooperative SM systems. They derive analytical expressions of the average bit error probability for both the newly proposed cooperative SM‐DF and cooperative SM‐AF systems and validate with the computer simulation results. Furthermore, they present the bit error rate comparison of considered systems with classical M ‐ary phase SK/quadrature amplitude modulation cooperative systems. Computer simulation results indicate that multiple antennas cooperative SM systems provide better error performance than classical cooperative systems for both relaying techniques.

Energy‐efficiency (EE) is a critical metric in many types of wireless networks and is getting increasingly important for new technologies. In this paper, the authors propose an energy‐efficient decode‐and‐forward relaying strategy for two‐hop diamond networks where the source–destination communication is established by the help of two relays which have an inter‐relay link. The inter‐relay link gives the opportunity of correcting the data packet between relays if only one of them decodes the packet that is received from the source correctly. Hence, both relays are able to send the data packet to the destination with distributed Alamouti coding which provides multipath diversity. In addition, they introduce optimum data rate adaptation for each link separately to maximise EE for the considered network. By exploiting diversity and optimum rate adaptation, it is possible to transmit at higher rates with reasonable outage probability which has critical effects on EE and throughput. They show via computer simulations that the proposed technique is substantially more energy‐efficient and has a better throughput than the successive relaying technique given in the literature; moreover, more robust to the changes in system conditions, i.e. relay location and transmission power level.

In this study, a new cooperative spectrum sharing protocol based on overlay system paradigm is proposed for different relaying strategies. In the considered model, a single‐antenna primary transmitter (PT) communicates with a primary receiver (PR) by the assistance of a secondary transmitter (ST) which seeks an opportunity to realise spectrum sharing by adopting spatial modulation (SM). The proposed protocol consists of two time slots. In the first time slot, primary M ‐ary modulated signal is transmitted from PT to ST and PR. ST processes the received signal according to the relaying strategy it adopts and transmits the processed signal by SM to PR and secondary receiver (SR) in the second time slot. Thanks to SM at ST, primary information is carried by conventional M ‐ary modulation whereas secondary information is conveyed by antenna indices. Therefore, the need for superposition of different users' information and power allocation at ST are avoided. Upper bounds on bit error probability according to three different relaying strategies: fixed and incremental amplify‐and‐forward, and selective decode‐and‐forward, are derived for both users. The theoretical results are supported via computer simulations and error performance comparisons with two existing reference systems are performed to show the superiority of the proposed protocol.

In this paper, a spectrum sharing protocol that combines coordinate-interleaved orthogonal design (CIOD) and space-time block coding is proposed for cognitive radio (CR) networks. Primary system's transmitter (PT) and receiver (PR) are equipped both by one antenna while secondary system's transmitter (ST) and receiver (SR) are equipped by two and one antennas, respectively. CIOD applied by means of PT and ST, provides signal-space diversity at PR and space-time block coding (STBC), especially Alamouti coding applied at two antennas of ST avoids interference at both PR and SR while providing spatial diversity for both receivers. An upper bound on the bit error probability (BEP) of primary system is analytically derived for Rayleigh fading channels and supported via computer simulations. The results show that the new protocol significantly improves the primary system bit error performance compared to the conventional non-cooperative case and the reference cooperative scheme based on the transmission of superimposed primary and secondary signals from ST which causes severe interference at both users; while allowing the secondary system's periodic access with an improved performance level.

In this paper, a new cooperative spectrum sharing protocol which avoids mutual interference between primary and secondary users by employing spatial modulation (SM) at the secondary transmitter (ST), is proposed for overlay cognitive radio networks. In the proposed protocol, ST cooperates with selective decode-and-forward (DF) relaying strategy to prevent error propagation. Primary transmitter (PT) exploits M-ary phase shift keying (M-PSK) modulation whereas ST utilizes SM (Nt transmit antennas and M- PSK). Since ST transmits PT's information by M-PSK symbols and its own information by antenna indexes, mutual interference at primary receiver (PR) and secondary receiver (SR) is removed. Upper bounds on the bit error probability (BEP) of the primary and secondary users are analytically derived and supported via computer simulation results which show that the proposed protocol significantly improves the bit error performance of both primary and secondary users compared to the non-cooperation case and the cooperative DF spectrum sharing protocol using superposition coding.

In recent years, energy efficiency (“greenness”) has become an important research topic in wireless networks. Environmental awareness and the increased cost of energy stimulate the research on this subject. In cellular networks, most of the power consumption takes place at the base stations (BSs). It is worth noting that the number of BSs has been steadily increasing since the 1G networks; moreover, this increase is expected to become even steeper in the foreseeable future with the advent of the small cell concept in the envisioned 5G networks. It is also worth noting that in cellular networks the traffic demand (load) in space and time is getting increasingly heterogeneous. As a result, parts of network will likely be lightly loaded at certain times. In such situations, it only makes sense to switch off as many BSs as possible without jeopardizing the key performance indicators. Although there in an increasing volume of literature on the cell switch-off (CSO) concept, to the best of our knowledge, there is no study which considers the user terminal (UT) power consumption as a key performance indicator, while the UT power efficiency indeed constitutes one of most important performance criterion in a mobile network. In many cases, switching off BSs for downlink energy efficiency may result in an uplink energy inefficiency, due to the fact that the UTs served by the switched off BSs will need to be connected to further away BSs. In this paper, we propose a heuristic CSO algorithm to achieve energy efficiency in the whole cellular network while taking into account the power consumption of UTs. We call the proposed algorithm as the user-aware CSO algorithm.

A new multiple-input multiple-output (MIMO) transmission scheme named\textit{ trellis coded space-shift keying} (TC-SSK) is proposed in this paper. This scheme is obtained by the combination of trellis coding and SSK for a given spectral efficiency, number of transmit antennas and trellis states. A soft decision Viterbi decoder is employed at the receiver to decode the transmitted SSK symbols. Using systematic methods, new TC-SSK schemes are obtained for 1 and 2 bits/s/Hz spectral efficiencies. An upper bound for the pairwise error probability (PEP) of the TC-SSK scheme is calculated for quasi-static Rayleigh fading channels. Computer simulation results show that the proposed TC-SSK schemes achieve significantly better error performance than the uncoded SSK, and the theoretical error probability curves are in close match with the computer simulation results. Furthermore, TC-SSK provides an attractive trade- off between complexity and performance compared to the spatial modulation with trellis coding.

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.

Emerging two-path successive relaying protocols generally rely on error-free source-relay channels and/or interference-free inter-relay channels to achieve high-rate and full-diversity. In this paper, by removing these optimistic assumptions, a novel two-path successive relaying scheme that benefits from relay selection and distributed space-time block coding (STBC), and transfers the data from the source to the destination via relays in a reliable fashion is proposed. The proposed scheme can achieve full diversity without the requirement of perfect decoding at relays since not only the destination but also the relays benefit from distributed STBC and relay selection. As the target STBC, coordinate interleaved orthogonal design (CIOD) for two transmit antennas is considered. The average symbol error probability of the proposed scheme is derived and its error performance is compared with reference systems.

In the above named paper [ibid., vol. 61, no. 5, pp. 1776–1785, May 2013], the authors correct an error from equation (12) and (13), on the variance of z given g and s that is expressed correctly in (14). This correction affects (15), (16), (17) and finally the optimal combining coefficient αMDC,igiven in (18) which should be modified as noted by the authors. Note that, the approximated maximum deflection coefficient given in Lemma 2 should be similarly corrected and (32) should be modified as further noted.

In this paper, a novel orthogonal frequency division multiplexing (OFDM) scheme, which is called OFDM with index modulation (OFDM-IM), is proposed for frequency-selective fading channels. In this scheme, inspiring from the recently introduced spatial modulation concept for multiple-input multiple-output (MIMO) channels, the information is conveyed not only by M-ary signal constellations as in classical OFDM, but also by the indices of the subcarriers, which are activated according to the incoming bit stream. Different transceiver structures are proposed and a theoretical error performance analysis is provided for the new scheme. It is shown via computer simulations that the proposed scheme achieves significantly better error performance than classical OFDM due to the information bits carried in the spatial domain by the indices of OFDM subcarriers.

Spatial modulation (SM), which employs the indices of multiple transmit antennas to transmit information in addition to the conventional M-ary signal constellations, is a novel transmission technique that has been proposed for multiple-input multiple-output systems. In this study, a new class of space-time trellis codes, called ‘super-orthogonal trellis-coded SM’ (SOTC-SM), is proposed. These codes combine set partitioning and a super set of space-time block coded SM (STBC-SM) codewords to achieve maximal diversity and coding gains by exploiting both SM and space-time block codes. Unlike super-orthogonal space-time trellis codes (SOSTTCs), which parametrise the orthogonal STBCs, these new codes expand the antenna constellation using the principle of SM. Systematic construction methods are presented for the SOTC-SM scheme and design examples are given for 2, 4 and 8 trellis states, at 2, 3 and 4 bits/s/Hz spectral efficiencies. The approximate bit-error probability performance of SOTC-SM is derived and shown to match computer simulation results. A simplified maximum likelihood detection method for the proposed scheme is given. It is shown through computer simulations that the proposed SOTC-SM schemes achieve significantly better error performance than SOSTTCs with comparable complexity.

In this study, the authors introduce the limited feedback technique into the physical-layer network coding which is the most spectrally efficient protocol for two-way relay channels, consisting of one relay and two end (source) nodes. In amplify-and-forward strategy, each source node obtains full channel state information (CSI) of the channel between relay and itself from training sequences and partial CSI of the channel between relay and the other node by means of a limited number of feedback bits provided by the relay. In the decode-and-forward strategy, the authors completely remove training sequences and the source nodes provide the partial CSI of the link between relay and themselves from limited feedback bits, the CSI of the other link being useless for this strategy. Tight upper bounds on the bit error probability depending on the number of feedback bits are derived for binary phase shift keying (PSK) and quadrature-PSK modulations for both strategies. It is shown via computer simulations that the bit-error-rate performance of the system with full CSI at all nodes is achieved for both strategies by using a few number of feedback bits. Moreover, the computation complexity is reduced for the proposed scheme with a single antenna at all nodes.

In this paper, we propose a novel MIMO transmission scheme, called trellis coded spatial modulation (TC-SM) in which the trellis (convolutional) encoder and the spatial modulation (SM) mapper are jointly designed similar to the conventional trellis coded modulation (TCM). A soft decision Viterbi decoder, which is fed with the soft information supplied by the optimal SM decoder, is used at the receiver. We derive the pairwise error probability (PEP) upper bound for the TC-SM 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 TC-SM schemes using QPSK (quadrature phase-shift keying) and 8-PSK modulations for 2 bits/s/Hz and 3 bits/s/Hz spectral efficiencies, respectively. We show by computer simulations that the proposed TC-SM schemes achieve significantly better error performances than their counterparts at the same spectral efficiency with reduced decoding complexity.

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.

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.

A new coordinate interleaved user cooperation scheme for distributed Alamouti space-time block code (DSTBC) is presented. When coordinate interleaved symbols are transmitted using DSTBC, a diversity order of four is reached at the destination for perfect cooperation (PC) of two users. A selective cooperation (SC) approach is proposed to prevent detrimental effect of the interuser channel. Error performance of the proposed coordinate interleaved DSTBC (CI-DSTBC) for PC and SC in noisy interuser channel is evaluated by computer simulations for QPSK modulation and its superiority compared to the corresponding counterparts given in the literature is brought out.

Space-time block coded spatial modulation (STBC-SM), which employs space-time block coding (STBC) for spatial modulation (SM), is proposed as a new multiple-input multiple-output (MIMO) transmission scheme. 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, therefore both core STBC and antenna indices carry information. A general framework is presented for the design of the STBC-SM scheme for any number of transmit antennas. The proposed scheme is 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. It is shown by computer simulations that STBC-SM provides approximately 3–5 dB (depending on the spectral efficiency) better error performance than SM and V-BLAST systems.

This paper presents a novel cooperative transmission scheme based on superposition modulation and incremental relaying. Incremental relaying is provided by a hybrid automatic-repeat-request (ARQ) type feedback channel. In the proposed scheme, users utilize decode-and-forward method with superposition modulation in which each user superimposes partner's signal if the destination has sent a negative acknowledgement (NACK) in the previous slot. In other words, relaying is performed under the control of feedback data. In case of an acknowledgment (ACK) from the destination, the users transmit merely their own signal. It is shown that at low signal-to-noise ratio (SNR) values the proposed scheme has a better diversity gain than the classical superposition modulated cooperative transmission and is about 1.5-2 dB better in error performance than the existing superposition based decode-and-forward cooperative scheme which means that incremental relaying brings significant gain in SNR.

The authors deal with the design of high-rate, full-diversity, low-maximum likelihood (ML) decoding complexity space-time block codes (STBCs) with code rates of 2 and 1.5 complex symbols per channel use for multiple-input multiple output (MIMO) systems employing three and four transmit antennas. The authors fill the empty slots of the existing STBCs from coordinate interleaved orthogonal designs (CIODs) in their transmission matrices by additional symbols and use the conditional ML decoding technique, which significantly reduces the ML decoding complexity of non-orthogonal STBCs while ensuring full-diversity and high coding gain. First, two new schemes with code rates of 2 and 1.5 are proposed for MIMO systems with four transmit antennas. The authors show that our low-complexity rate-2 STBC outperforms the corresponding best STBC recently proposed by Biglieri et al. (2008) for quadrature phase shift keying (QPSK), due to its superior coding gain while our rate-1.5 STBC outperforms the full-diversity quasi-orthogonal STBC (QOSTBC). Then, two STBCs with code rates of 2 and 1.5 are proposed for three transmit antennas, which are shown to outperform the corresponding full-diversity QOSTBC. The authors prove by an information-theoretic analysis that the capacities of new rate-2 STBCs for three and four transmit antennas are much closer to the actual MIMO channel capacity than the capacities of classical OSTBCs and CIODs.

A two-user coordinate interleaved coded cooperation scheme is proposed for quasi-static Rayleigh fading channels, where cooperative and modulation diversity techniques are properly combined to take their full advantage. Two selective cooperation schemes are considered related to whether users know the cooperation case or not. Pairwise error probability (PEP) analysis is performed for all cooperation cases and code design criteria are derived from the PEP upper bounds. Bandwidth-efficient 4-, 8- and 16-state rate 2/4 cooperative quadrature phase shift keying (QPSK) trellis codes are obtained based on these criteria by means of exhaustive computer search. The error performances of the new codes evaluated by computer simulations show their superiority compared to the corresponding best space–time codes used in cooperation with coordinate interleaving. The simulation results are supported by an upper bound on the bit error probability developed using union bounding technique.

In this paper, we present a new full-rate, full-diversity coordinate interleaved design (CID) for multiple-input multiple-output (MIMO) systems with two transmit antennas. When compared with the conventional space-time block codes (STBCs) and coordinate interleaved orthogonal designs (CIODs), the proposed scheme is above the predefined full-rate limits since we ignore the pure orthogonality principle while transmitting extra symbols from available slots. The higher complexity of this structure due to non-orthogonality is reduced by using a simple conditional maximum-likelihood (ML) decoder. The new CID achieves full-diversity with a high minimum determinant, and outperforms its counterpart given by Sezginer and Sari with certain constellations, which make it to be considered for the future high data rate wireless applications.

In this paper, we propose an efficient concatenated trellis coded modulation (TCM) and coordinate interleaved space- time block coded (STBC) orthogonal frequency division multiplexing (OFDM) system providing full spatial and multipath diversity with considerable diversity increase compared to the techniques given in the literature. The pairwise error probability (PEP) analysis of the proposed system for two transmit antennas shows that the achievable diversity is doubled and a signal to noise ratio (SNR) gain of approximately 3 dB is provided for the same codeword error rate (CER) compared to the concatenated TCM and STBC OFDM system given in Y Gong & K B Letaief (2003) with modest increase in coding and decoding complexities.

In this paper, a two-user cooperative diversity scheme is proposed where coded cooperation and modulation diversity techniques are properly combined to take their full advantage. Users perform selective cooperation in transmission according to the correct estimation of symbols from their partners. Pairwise error probability analysis is performed for all cooperation cases and a tight upper bound on the bit error probability is obtained for rate compatible punctured convolutional codes and QPSK modulation. Numerical results show that the proposed system outperforms the coded cooperation technique given in by achieving two times more diversity.

Super-orthogonal space-time trellis codes (SOSTTCs) given in the literature are full rate and provide full spatial diversity with high coding gain in narrowband quasistatic fading channels. The high number of parallel transitions in their trellis structure restricts their performance in wideband channels where the code performance suffers from multipath. Code design criteria are derived and a computer search based method is proposed to design full-rate optimised SOSTTCs exploiting full spatial and multipath diversity for multiple-input multiple-output orthogonal frequency division multiplexing systems. The proposed codes have codewords defined in space, time, and frequency. We evaluate the codeword error rates of the new 16, 32 and 64-state super-orthogonal space-time-frequency trellis codes for quadrature phase shift keying by computer simulation and show that they provide significant error performance improvement compared to their counterparts with equivalent delay length.

In this paper, we propose a full rate space-time block code selection technique, which achieves full diversity when more than two transmit antennas are used for transmission. Only one or few feedback bits are needed at the transmitter, representing relative state information of the channels. Moreover, the proposed scheme allows separate decoding of transmitted symbols at the receiver. It is shown by computer simulations that, the new approach provides SNR improvement, especially when feedback errors occur, compared to the transmit antenna selection technique associated with Alamouti's scheme, for the same number of feedback bits

We propose a novel coding scheme, which guarantees full diversity for any number of transmit antennas, provided that few bits of feedback from the receiver to the transmitter are available. This coding scheme is arranged as an extension of orthogonal space-time block coding and preserves its linear decoding complexity. Moreover, it is full rate when the underlying coding method is the Alamouti's scheme. It is shown by computer simulations that the new approach provides SNR improvement, and it is more resilient to feedback errors compared to the antenna selection technique on the basis of same number of feedback bits.

In this paper, an optimum sequence estimation algorithm for wireless systems with Alamouti's two transmitter diversity in the presence of multipath fading is proposed. The algorithm is based on a jointly iterative channel and sequence estimation according to the maximum likelihood (ML) criterion, using the expectation-maximization (EM) algorithm employing M-PSK modulation scheme with additive Gaussian noise. The discrete multipath channel is represented in terms of the channel gains from each transmit antenna to the receive antenna. The derived EM algorithm jointly estimates the complex channel parameters of each channel and the data sequence transmitted, iteratively, which converges to the true ML solution. The channel estimation is achieved in a simple way through the iterative equations by decoupling of the signals transmitted from different antennas. The algorithm is applied to the trellis coded modulation systems and efficiency of the algorithm proposed has been shown by the computer simulations. Simulation results show that the EM algorithm converges quickly for fast fading channels. The performance of the EM-based decoder approaches that of the ML receiver which has perfect knowledge of the channel.

The authors comment that in the paper of Yuan, Vucetic and Feng (see ibid., vol.47, p.484-87, Apr. 1999), the optimum distance spectrum (ODS) code found for memory order v=5, is actually v=3 convolutional code. The ODS code with h/sub 0/=43/sub s/ and h /sub 1/=55/sub s/ is actually v=3 code, because the feedback polynomial h/sub 0/, and feedforward polynomial h/sub 1/ are not relatively prime polynomials.

The performance of data communication systems over wireless channels is severely degraded by the multipath fading effects. Space-time codes exploit the channel capacity increase by using multiple transmit and/or receive antennas. This ensures space diversity without expanding the required transmission bandwidth. A type of space-time codes, namely orthogonal transmit diversity (OTD), has attracted much attention. This scheme has low complexity and can achieve maximum diversity. However, error performance of OTD systems decreases in the absence of perfect channel state information at the receiver. We present an enhanced power control scheme for OTD systems with two transmit and multiple receive antennas. Simulation results have been presented to show the performance improvement.

In this paper, we introduce multilevel coded continuous-phase frequency-shift keying (CPFSK) systems for both additive white Gaussian noise and fading channels based on multilevel coding and multistage decoding techniques. These schemes are designed under the constraint M/spl ges/2P for M-ary CPFSK with modulation index J/P. In order to maintain the phase continuity property after multilevel coding, we use some specific set partitioning rules. We construct examples to show that the proposed systems outperform the corresponding conventional one-level schemes. For the fading case, we consider an ideal fading channel where adjacent fading symbols are assumed to be independent and a correlated fading channel where bit interleavers are needed at each coding level. The computer simulation results show that the proposed systems have bit-error performance and decoder complexity advantages over the corresponding reference codes taken from the literature. It is also shown that there is only a slight degradation on the bit-error performance for correlated fading, compared to the ideal fading case.

In order to improve the bandwidth efficiency and error performance, partial response signaling (PRS) and trellis coded modulation (TCM) are combined together. This method is named QPR-TCM. Whereas previous contributions have considered the performance of TCM transmitted over an additive white Gaussian noise (AWGN) channel, the emphasis in this paper is on the performance of trellis coded M-ary QAM combined with PRS in the fading environment. We only consider the case where interleaving/deinterleaving is employed to further combat the fading and assume that the ideal channel state information (CSI) is available. Analytical upper bounds are derived using the well known transfer function bounding technique, the bandwidth efficiencies are computed and the numerical results for several practical schemes are compared to each other. One interesting result is that when the combined system is used on a Rician fading channel, the bit error probability upper bounds of the proposed 6QPR-TCM and 9QPR-TCM systems are better than their counterparts the 4QAM-TCM systems with 2 and 4 states, respectively, for SNR values greater than a threshold, which have the best error performances in the literature.>

The trellis coding technique is applied to line-coded baseband digital transmission systems. For R=n/n+1(n=1,2,3) coding rates, a new codeword assignment model is proposed to accomplish basic requirements for line coding in which each length n binary data sequence is encoded into a length n+1 ternary (+,0,-) line codeword chosen among the code alphabet with 2/sup n+2/ elements. Assuming Viterbi decoding, the system error performance is improved by increasing the free Euclidean distance between coded sequences. A new algorithm is given for the calculation of the free distance between line-coded sequences so obtained. For R=1/2 and R=3/4 rates, the analytical error performance upper bounds are derived. The power spectral densities of the new line codes are also calculated and compared with those of known line codes.>

To improve both bandwidth efficiency and error performance, partial response signaling and trellis coded modulation are considered together for QAM. A new receiver for a data transmission system employing combined partial response/trellis coded modulation (QPR-TCM) is investigated. Combined 6QPR-TCM and 42QPR-TCM systems are introduced. Simulation studies in the ISI environment are done. In a colored noise environment, the error probability of 6QPR-TCM is analytically lower bounded and compared to the classical 4QAM-TCM. An optimal (QPR-TCM) scheme is proposed which improves both jitter and error response in a colored noise environment.>

https://doi.org/10.1109/pimrc.1991.571481