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In this paper a new maximum likelihood (ML) based detector for multi-input multi-output (MIMO) channels in spatio-temporal colored noise fields is proposed. It is assumed a Kronecker model of spatio-temporal correlation of noise. Approximate ML (AML) detection algorithm of MIMO channels is considered for two cases: known noise correlation matrix and unknown noise correlation matrix. The ML decoder...
We investigate successive interference cancellation (SIC) detectors that can achieve a close to optimum BER performance in spatial multiplexed multi-input multi-output (SM-MIMO) systems. We propose a low-complexity interference suppression strategy, in which an enhanced SIC is devised by introducing the feedback diversity to combat the error propagation in decision feedback loops. In order to constrain...
A novel iterative detection scheme for MIMO-OFDM systems is proposed in this work. We show that the existing detection schemes are sub-optimum and the iterative process can be optimized by utilizing the non-circular property of the residual interference after interference cancellation. Results show that the proposed iterative scheme outperforms the conventional iterative soft interference cancellation...
We develop accurate one-dimensional Extrinsic Information Transfer (EXIT) chart methods for the design of Raptor codes over arbitrary parallel AWGN channels and slow-fading MIMO channels with CSIR. The code design is optimized over any desired finite set of operating points, each of which is specified by a channel matrix. We develop techniques to minimize the number of constraining channel matrices...
In this paper we study the performance of space-time bit-interleaved coded modulation (ST-BICM) over block-fading multi-input multi-output (MIMO) channels with iterative receivers based on minimum mean square error (MMSE) detection. We show how full diversity can be achieved with a special class of space-time precoders. Performance in terms of symbol error rate (SER) and word error rate (WER), obtained...
In this paper, a new approach to construct LDMC codes is introduced. The new codes can be encoded efficiently at the transmitter side and support both of the inner-iterations and outer-iterations at the receiver side. Furthermore they can achieve the design rates and perform very well over MIMO channels.
A novel concatenated multi-input multi-output (MIMO) communication system based on time varying linear transformation (TVLT) and Tanner codes is proposed in this paper. The girth 4 property of Tanner codes is discussed briefly. Combined with the outstanding distance property of Tanner codes, TVLT can provide full diversity and maximum coding gain at the same time without exhaustive search for the...
In this paper, the variational expectation-maximization (VEM) algorithm is used to provide channel estimates in a space-time decoder. The proposed estimator works for many types of space-time codes (STC), including full-rate full-diversity (FRFD) codes, Bell Laboratories layered space-time architecture (BLAST) and orthogonal STC's. The principle idea is to treat the channel coefficients as the unknown...
By modeling the corresponding MIMO channel as a factor graph (FG), STBC decoder, bit interleaver and LDPC decoder can be combined together to form a larger joint factor graph (JFG). Extrinsic information transfer (EXIT) charts and bit error rate (BER) results show that the JFG enables a shuffled decoding superior to the classical serial iterative detection in performance while reducing complexity.
Multiple-input multiple-output (MIMO) wireless technology is the key to meet the demands for data rate, quality-of-service, and bandwidth-efficiency of modern wireless communication systems. MIMO technology is therefore adopted in many recent communication standards, such as IEEE 802.11n. Here, the MIMO detector has a strong impact on the overall system performance. In fact, the full potential of...
3GPP LTE has become a hot topic in recent years. One of its main challenges is the computationally intense task of MIMO detection. This paper investigates MIMO detection methods based on Sphere detection for 3GPP LTE system. A 3GPP LTE simulation chain has been developed for the evaluation. The results show that TS algorithm in combination with complexity reduction techniques of SSD and ME achieves...
An iterative receiver for a multiple-input multiple-output (MIMO) orthogonal frequency-division multiplexing (OFDM) system is considered to jointly decode the transmitted bits and estimate the channel state. The receiver consists of the a posteriori probability (APP) algorithm, the repeat-accumulate (RA) decoder, and the least-squares (LS) channel estimator. An obvious problem, with more than two...
In this paper, the rate achievable in Multiple-Input-Multiple-Output (MIMO) systems with iterative receivers based on linear front-end (FE) processing is investigated. First, the communication with Gaussian input signal is assumed and the Extrinsic Information Transfer (EXIT) chart is applied to evaluate the achievable sum rate. Then, the method for deriving the EXIT chart for a more practical case...
Iterative Soft-Input Soft-Output (SISO) detection and channel decoding offer significant improvement in error-rate performance for a reduced signal-to-noise ratio. With Multiple-Input Multiple-Output (MIMO) technology being part of many wireless system standards, several low-complexity suboptimal detection algorithms have been proposed. In this paper, a detailed flexibility and convergence analysis...
In this treatise, we propose an iteratively decoded Bell-labs LAyered Space-Time (BLAST) scheme, which serially concatenates an IRregular Convolutional Code (IRCC), a UnityRate Code (URC) and a BLAST transmitter. The proposed scheme is capable of achieving a near capacity performance with the aid of our Extrinsic Information Transfer (EXIT) chart assisted design procedure. Furthermore, a Markov Chain...
In classical non-iterative MIMO detection a soft-output MIMO detector computes likelihoods of the transmit bits being 1 or 0, given the received symbol vector. In iterative MIMO detection-decoding, detection performance is improved by exploiting apriori information about bit probabilities from the decoder. Transmit bits are viewed as random variables and the optimum detector performs Bayesian updating...
The Turbo receiver for MIMO channels employs a soft-input, soft-output (SISO) detector followed by a SISO channel decoder. In this letter, we describe and analyze two low complexity SISO detectors named as M-Partial-MAP and LPartial-MAP for LDPC coded MIMO systems. The latter performs slightly better than the former at the price of some computational complexities.
In this paper the application of the recently proposed interleave-division multiplexing space-time codes (IDM-STC) in coded relay networks is investigated. IDM-STC are a very flexible scheme to exploit space diversity with the benefits of IDM such as robustness against asynchronism and efficient iterative detection. While IDM-STC have been investigated for MIMO systems, relay networks induce additional...
This paper proposes a Dempster-Shafer theory (DST)-based iterative detection-decoding scheme in multiple-input multiple-output (MIMO) systems. On the one hand, the detection algorithm takes advantage of the characteristics of DST processing uncertainty, improving detection performance. On the other hand, during iterations the detection scheme allows for the soft information outputs from the decoder...
Using the Schnorr-Euchner (SE) order for soft-input sphere decoders is inefficient for implementation, because it requires exhaustive calculation and sorting of partial metrics of all constellation points. Instead, low-complexity methods can be applied by separating the partial metric into channel information and a priori information and solely enumerating based on one of them. With such an orthogonalization,...
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