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This paper considers multi-access relay networks (MARNs) where two single-antenna users communicate to one N-antenna receiver via two hops of transmissions through one R-antenna relay. Nodes in the network are under two linear constraints. The relay linearly maps its received signal to generate its forwarding signal without decoding; the receiver has linear decoding complexity in the number of users...
Signal space diversity technique has been widely adopted in wireless communication systems to combat channel fading by exploiting time diversity, frequency diversity, spatial diversity or a combination of them. Most existing signal space diversity schemes are based on linear constellation spreading. In this paper, we propose a novel nonlinear signal space diversity technique based on maximum distance...
In this paper, we propose a systematic design of space-time block codes (STBC) which can achieve high rate and full diversity when the partial interference cancellation (PIC) group decoding is used at receivers. The proposed codes can be applied to any number of transmit antennas and admit a low decoding complexity while achieving full diversity. For M transmit antennas, in each codeword real and...
In this paper a novel detection algorithm for spatial modulation (SM) based on sphere decoder (SD) tree search idea is proposed. The aim is to reduce the receiver complexity of the existing optimal decoder while maintaining an optimum performance. The algorithm performs a maximum likelihood (ML) search, only over those points that lie inside a sphere, centered at the received signal, of given radius...
For a family/sequence of Space-Time Block Codes (STBCs) C1, C2, ..., with increasing number of transmit antennas Ni, with rates Ri complex symbols per channel use, i = 1, 2,..., the asymptotic normalized rate is defined as limi→∞ Ri/Ni. A family of STBCs is said to be asymptotically-good if the asymptotic normalized rate is non-zero, i.e., when the rate scales as a nonzero fraction of the number of...
In this paper, we present new constructions of quasi-orthogonal space-time block codes for 4 and 6 transmit antennas. The proposed codes possess the following properties: full-rate, full transmit diversity, even power distribution and low decoding complexity, which make these two codes very practical spacetime coding schemes. For the case of 4 transmit antennas, the code can be decoded pair-by-pair,...
This paper investigates non-binary low-density parity-check (LDPC) erasure correcting codes suitable to guarantee reliable transmission in wireless communications systems. In particular, irregular repeat-accumulate (IRA) codes are considered, characterized by linear-time encoding complexity. The performance of non-binary IRA codes is compared with their binary counterparts on the packet erasure channel...
In this paper a novel scheme is introduced to perform the soft input decoding of Reed Solomon Codes using iterative bit flipped decoding based on the LLRs of the received bits. MAP is used as the inner decoder to obtain the LLRs for the decoded bits at the receiver. In case of decoding failure or a decoding error by the outer RS decoder, a combination of bits from the received word are flipped based...
The goal of a communication system is to optimally utilise the scarce spectrum and the energy required to transmit information while maintaining a specific quality of service. In this paper, it is proposed to communicate information by using new ternary line coders with code rates R = ½, 2/3 and ¾ as invented by Aygolu and Panayirci [1]. The encoding/decoding is based on the convolutional coding and...
In this paper, a new search strategy based on a derived cumulative distribution function (cdf) is proposed. It is shown that incorporating detection ordering into the conventional K-Best sphere decoding algorithm (SDA) offers a systematic method for determining the numbers of required ML search layers. With the features, applying the proposed search strategy to conventional complex K-Best SDA, the...
DNA data embedding is a relatively recent area which aims at embedding arbitrary information in deoxyribonucleic acid (DNA) strands. One interesting application of DNA data embedding can be tracing pathways of genetic material in novel ways. This paper explores the decoding performance of several DNA data embedding algorithms proposed in the literature, which are also briefly reviewed. DNA may undergo...
A universal design of low-density parity-check (LDPC) code ensembles which enables to operate reliably over various channels is of great interest. This paper considers the universality of LDPC code ensembles over sets of memoryless binary-input output-symmetric (MBIOS) channels, addressing their universality under belief-propagation (BP) and maximum-likelihood (ML) decoding. Based on the density evolution...
Linear constellation precoded orthogonal frequency division multiplexing (LCP-OFDM) requires a maximum likelihood (ML) decoder to fully collect multipath diversity gain. However, the complexity of ML increases exponentially with the channel memory, signal constellation size, and the number of transmit/ receive antennas. Therefore, linear equalizers are highly desirable. This paper mainly analyzes...
It is well established that cycles in the Tanner graphs associated with error correction codes introduces biases into message passing decoding and result in poor performance as the number of cycles in the graph increases. The decoder in this paper addresses the problem of cycles by two methods: (1) Computing exact probabilities by marginalizing the exact probability obtained using clique potential...
In this work, we focus on the use of network coding in a wireless sensor network where data is already encoded at the source node with fountain codes, in particular LT or Raptor codes. These codes have a specific degree distribution to follow in order to obtain an efficient decoding process. However, adding a layer of network coding on such packets triggers a distorsion of the degree distribution...
The fixed-complexity sphere decoder (FSD) has been proposed to attain the near-optimal performance achieving the same diversity order as the maximum-likelihood decoder (MLD). However, it suffers great redundant computations resulting in very high power consumption. In this paper, we combine the probabilistic tree pruning (PTP) method proposed recently by Shim and Kang with the original FSD. This algorithm...
By making use of the characteristic of the cost function MSSO (Mean of the Square Soft Outputs), a new method of carrier phase synchronization and decoding for the turbo-coded systems is presented. Firstly, a short training sequence is used to achieve the initial phase estimation and to narrow the phase searching range. Secondly, three decoding sequences with the largest MSSO values are chosen by...
The paper has a unique insight into the recently emerging erasure correcting codes, LT codes, in terms of its crucial structure of Robust Soliton Distribution in the truncation form. We propose a truncation scheme on the original degree distribution to achieve a higher decoding success probability while slightly decreasing the operational complexity. We test the influence of the truncation length...
This paper presents a 3GPP LTE compliant turbo decoder accelerator on GPU. The challenge of implementing a turbo decoder is finding an efficient mapping of the decoder algorithm on GPU, e.g. finding a good way to parallelize workload across cores and allocate and use fast on-die memory to improve throughput. In our implementation, we increase throughput through 1) distributing the decoding workload...
A novel constellation mapping VBLAST zero forcing detection algorithm in MIMO-OFDM system is proposed in this paper. First, the signal is cycled and successively mapped from the whole space of constellation points and is regarded as the first the underlying detection signals to maximize the performance of the first detection layers at the receiver. Then, the traditional ZF detection algorithm is used...
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