In this paper, we investigate iterative detection and decoding, a.k.a. turbo detection, for multiple-input multiple-output (MIMO) transmission. Specifically, we consider using a low complexity soft-in/soft-out MIMO de...
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In this paper, we investigate iterative detection and decoding, a.k.a. turbo detection, for multiple-input multiple-output (MIMO) transmission. Specifically, we consider using a low complexity soft-in/soft-out MIMO detector based on belief propagation over a pair-wise graph that accepts a priori information feedback from a channel decoder. Simulation results confirm that considerable performance improvement can be obtained with only a few detection-and-decoding iterations if convolutional channel coding is used. A brief estimate is given of the overall complexity of turbo detectors, to verify the key argument that the performance of a maximum a posteriori (MAP) detector (without turbo iteration) can be achieved, at much lower computation cost, by using the low complexity soft-in/soft-out MIMO detector under consideration.
This paper considers detection and error control coding for the 2-D magnetic recording (TDMR) channel modeled with the 2-D four-rectangular-grain model (FRGM). This simple model captures the effects of different 2-D g...
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This paper considers detection and error control coding for the 2-D magnetic recording (TDMR) channel modeled with the 2-D four-rectangular-grain model (FRGM). This simple model captures the effects of different 2-D grain sizes and shapes, as well as the TDMR grain overwrite effect. We construct a row-by-row Bahl-Cocke-Jelinek-Raviv-based detector that processes two rows at a time. Simulation results using the same coded bit density and channel code as a previous paper on FRGM detection show gains in user bits per grain of up to 13.4% when the detector and the decoder iteratively exchange soft information, resulting in densities higher than 0.5 user bits per grain under all scenarios simulated. When the proposed detector/decoder operates on coded bits read from a random Voronoi grain model, the achieved density drops to 0.25 user bits per grain due to model mismatch between the detector and the data. Finally, this paper considers an iterative detection and decoding scheme combining TDMR detection, 2-D-intersymbol interference (ISI) detection, and soft-in/soft-out channel decoding in a structure with two iteration loops. Simulation results for the concatenated FRGM and 2 x 2 averaging mask ISI channel with 10 dB signal-to-noise ratio show that densities of 0.496 user bits per grain and above can be achieved over the entire range of FRGM grain probabilities.
An iterative detection and decoding algorithm with outer code decision feedback is proposed for the dual polarized( DP) land mobile satellite( LMS) MIMO systems using concatenated codes. A feedback structure is added ...
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An iterative detection and decoding algorithm with outer code decision feedback is proposed for the dual polarized( DP) land mobile satellite( LMS) MIMO systems using concatenated codes. A feedback structure is added after the outer decoder in the proposed algorithm. The feedback information is exploited to control the detecting list in the MIMO detector and reduce the number of symbols which have to be processed at each iteration. As a result,the computational complexity is reduced. Meanwhile,the successfully decoded outer code words are used to calculate the more reliable initial information for the inner decoder and the system performance can be improved by this step. The simulation results show that the proposed algorithm can reduce the computational complexity compared to the traditional iterative detection and decoding algorithm and achieve better performance.
In this paper, the design of iterative detection and decoding (IDD) schemes relying on a low-complexity probabilistic data association (PDA) aided method is conceived for turbo-coded multiple-input multiple-output (MI...
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ISBN:
(纸本)9781467309219;9781467309202
In this paper, the design of iterative detection and decoding (IDD) schemes relying on a low-complexity probabilistic data association (PDA) aided method is conceived for turbo-coded multiple-input multiple-output (MIMO) systems communicating over Nakagami-m fading channels. The known PDA based MIMO detectors typically operate purely in the probability-domain. We show that the classic relationship where the extrinsic LLRs are given by subtracting the a priori LLRs from the a posteriori LLRs does not hold for the existing PDA based MIMO detectors. Therefore, the PDA method is not readily applicable to the IDD receiver. To overcome this predicament, we propose an approximate Bayesian theorem based log-domain PDA (AB-Log-PDA) detector, as well as a novel simple approach of calculating the bit-wise extrinsic LLRs for the AB-Log-PDA, which makes the AB-Log-PDA well-suited for employment in IDD receivers. It is shown that the proposed AB-Log-PDA based IDD scheme is capable of achieving a comparable performance to that of the optimal maximum a posteriori (MAP) detector based IDD receiver, while imposing a much lower computational complexity in the scenarios considered.
Low-resolution precoding techniques have gained considerable attention in the wireless communications area recently. Vital but hardly discussed in literature, discrete precoding in conjunction with channel coding is t...
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ISBN:
(纸本)9781728157672
Low-resolution precoding techniques have gained considerable attention in the wireless communications area recently. Vital but hardly discussed in literature, discrete precoding in conjunction with channel coding is the subject of this study. Unlike prior studies, we propose three different soft detection methods and an iterative detection and decoding scheme that allow the utilization of channel coding in conjunction with low-resolution precoding. Besides an exact approach for computing the extrinsic information, we propose two approximations with reduced computational complexity. Numerical results based on PSK modulation and an LDPC block code indicate a superior performance as compared to the system design based on the common AWGN channel model in terms of bit-error-rate.
Expectation propagation (EP) has recently been considered with iterative detection and decoding (IDD) to enhance the bit error rate (BER) performance for coded massive Multiple-input Multiple-output (M-MIMO) system. H...
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Expectation propagation (EP) has recently been considered with iterative detection and decoding (IDD) to enhance the bit error rate (BER) performance for coded massive Multiple-input Multiple-output (M-MIMO) system. However, current state-of-the-art (SOA) EP-based IDD schemes like double-EP (DEP) are still far from realization due to unaffordable latency brought by their serial structure and large computational complexity. To relieve this issue, in this article, an efficient EP-based parallel IDD method is proposed for coded M-MIMO. First, by investigating the factor graph (FG)-based message passing in EP-based IDD, a double non-resetting framework named EP-dNRe is proposed to improve the IDD efficiency. Based on this framework, a novel parallel EP-based IDD scheme named EP-based parallel detection and decoding (PDD-EP) is further proposed. After proper initialization, the parallel loops of PDD-EP can execute the EP detection and decoding modules simultaneously, which brings latency reduction and improved performance-complexity trade-off. Simulation results and complexity analysis are presented to confirm the efficiency of the proposed PDD-EP. Particularly, both DEP with double non-resetting (DEP-dNRe) and PDD-EP can greatly reduce the required number of iterations to reach the same performance as the SOA DEP. Furthermore, the proposed PDD-EP can attain the same BER as DEP-dNRe with about 33.1% less complexity, and outperforms DEP-dNRe up to 0.2 dB by similar complexity in various LDPC-coded M-MIMO systems.
We present a new algorithm for joint detection and decoding of iteratively decodable codes transmitted over channels affected by a time-varying phase noise (PN) and a constant frequency offset. The proposed algorithm ...
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We present a new algorithm for joint detection and decoding of iteratively decodable codes transmitted over channels affected by a time-varying phase noise (PN) and a constant frequency offset. The proposed algorithm is obtained as an application of the sum-product algorithm to the factor graph representing the joint a posteriori distribution of the information symbols and the channel parameters given the channel output. The resulting algorithm employs the soft-output information on the coded symbols provided by the decoder and performs forward-backward recursions, taking into account the joint probability distribution of phase and frequency offset. We present simulation results for high-order coded modulation schemes based on low-density parity-check codes and serially concatenated convolutional codes, showing that, despite its low complexity, the algorithm is able to cope with a strong PN and a significant uncompensated frequency offset, thus avoiding the use of complicated data-aided frequency-estimation schemes operating on a known preamble. The robustness of the algorithm in the presence of a time-varying frequency offset is also discussed.
This study proposes Kalman combining-based iterative detection and decoding (KC-IDD) schemes for multiple-input multiple-output (MIMO) systems with hybrid automatic repeat request (HARQ). The conventional Kalman filte...
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This study proposes Kalman combining-based iterative detection and decoding (KC-IDD) schemes for multiple-input multiple-output (MIMO) systems with hybrid automatic repeat request (HARQ). The conventional Kalman filtering (KF) operation for Kalman combining performs the linear minimum mean-square error (LMMSE) detection with symbol-level combining (SLC), but it is unable to utilize a priori information of retransmitted symbols. Therefore, a new KF operation is derived, wherein an observation adjustment is employed to adjust the observation for a given state of the state-space model with the a priori information instead of directly utilizing it into the KF operation. Based on the modified KF operation, two KC-IDD schemes are developed: i) KC-IDD with the single-state observation adjustment, i.e., the observation adjustment for the current HARQ round, and ii) KC-IDD with multi-state observation adjustment (KC-IDD-MS), i.e., the observation adjustments throughout the HARQ rounds of a packet. Therefore, the proposed schemes can perform SLC-based LMMSE-IDD, where the complexity for a given number of turbo iterations is similar or smaller to that of the conventional LMMSE-IDD scheme with bit-level combining (BLC). Furthermore, the simulation results show that regardless of the retransmission strategy, the proposed schemes, especially the KC-IDD-MS scheme, outperformed the conventional LMMSE-IDD scheme in terms of error performance and decoding convergence speed for retransmissions.
In this letter, an efficient approximate expectation propagation (EPA) based iterative detection and decoding (IDD) scheme named EPA-IDD is first proposed for LDPC-coded massive MIMO systems. EPA is applied in IDD to ...
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In this letter, an efficient approximate expectation propagation (EPA) based iterative detection and decoding (IDD) scheme named EPA-IDD is first proposed for LDPC-coded massive MIMO systems. EPA is applied in IDD to bypass the variance updates in the inner loops, which reduces matrix inversions, simplifies extrinsic messages, and effectively enhance the convergence performance of IDD. In addition, a partial resetting scheme is proposed to efficiently adopt the decoder output into the EPA detector. A Neumann series based approximation called wNSA-EPA-IDD is further developed to reduce complexity. Numerical results show that the proposed EPA-IDD schemes outperform the state-of-the-art (SOA) double EP (DEP) in various LDPC-coded MIMO scenarios. Complexity analysis is presented to validate the improved efficiency of the proposed algorithms.
This paper presents an efficient iterative detection and decoding (IDD) receiver for polar-coded massive MIMO systems. The EP with approximation (EPA) algorithm is devised to relieve the computational burden of the de...
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ISBN:
(纸本)9798350325744
This paper presents an efficient iterative detection and decoding (IDD) receiver for polar-coded massive MIMO systems. The EP with approximation (EPA) algorithm is devised to relieve the computational burden of the detector. A modified belief propagation flip (mBPF) polar decoder is proposed to effectively improve the decoding performance with acceptable complexity cost. The messages passed between the detector and decoder are carefully designed to further improve the bit-error-rate (BER) performance. Numerical results are presented to demonstrate that the proposed IDD scheme can outperform both the separate detection and decoding (SDD) receiver with EP detector and successive cancellation list (SCL) decoder, and the state-of-the-art (SOA) double EP (DEP) IDD receiver with BP decoder. The corresponding complexity analysis and hardware architecture are also provided in this paper.
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