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In this paper, an improved K-best algorithm, which is suitable for low-complexity MIMO detector implementation is proposed. In order to balance the detector's bit-error-rate (BER) performance and computation complexity, several techniques, such as empirical path expansion and relaxed sorting have been proposed. Simulation results have shown that the proposed algorithm can achieve better computation...
Lattice reduction (LR) aided detectors mitigate the exponentially increasing complexity of large multiple-input, multiple-output (MIMO) systems while achieving near-optimal performance with low computational complexity. In this paper, a channel-adaptive complex-domain LR-aided K-best MIMO detector is presented that reduces the gap between the K-best sphere decoding (SD) detector and the maximum likelihood...
A configurable, channel-adaptive K-best MIMO detector for multi-mode wireless communications that adapts computation to varying channel conditions to achieve high energy-efficiency is presented. An 8-stage configurable MIMO detector supporting up to a 4×4 MIMO array and BPSK to 16-QAM modulation schemes has been implemented and simulated in 0.80V, 22nm Tri-gate CMOS process. Dynamic clock gating and...
Lenstra-Lenstra-Lovász (LLL) algorithm has been adopted as a lattice reduction (LR) technique for multiple-input multiple-output (MIMO) detection to improve error performance without exponential complexity. However, implementing the LLL algorithm is still challenging. During the execution of each LLL iteration, the column swap operations may not happen in some cases, which is not efficient in terms...
The increasing scale of Multiple-Input Multiple-Output (MIMO) topologies employed in forthcoming wireless communications standards presents a substantial implementation challenge to designers of embedded baseband signal processing architectures for MIMO transceivers. Specifically the increased scale of such systems has a substantial impact on the perfor-mance/cost balance of detection algorithms for...
This paper describes a successive multiuser detection technique for Direct Sequence Code Division Multiple Access (DS-CDMA) systems. In conventional CDMA system, single-user detection is employed, so that the interference between users or multiple access interference (MAI) component is considered as noise, which contributes to the statistics of detection variables affecting the quality of detection...
In this study, the performance of tracking and data relay satellite (TDRS) communication system multiple access (MA) service is analyzed. Firstly, in order to eliminate multiple access interference, a multiuser detector based on minimum mean square error (MMSE) and artificial fish swarm algorithm (AFSA) is explored. The result of MMSE and its modified formations are used as the initial values of artificial...
Transmission of a three-carrier 1.206 Tbit/s dual polarization 16-QAM superchannel over 1500 km of SMF is demonstrated using a modified fixed look-up table based maximum-a-posteriori detector to mitigate pattern-dependent distortion in the transmitted signal due to the high symbol rate.
An iterative detection and decoding (IDD) scheme based on component-level soft cancellation (CLSC) and linear minimum mean-squared error (LMMSE) filtering for turbo coded multiple input multiple output (MIMO) multiplexing systems is proposed in this work. By exploiting the independence between the In-phase and Quadrature-phase branch, more accurate soft interference cancellation is realized. Extrinsic...
Efficient receiver designs for cooperative communication systems are becoming increasingly important. In previous work, cooperative networks communicated with the use of relays. As the receiver is constrained, it can only process out of relays. Channel shortening and reduced-rank techniques were employed to design the preprocessing matrix. In this paper, a receiver structure is proposed which...
Lattice reduction (LR) is a powerful technique for improving the performance of linear MIMO detection methods. The efficient LR algorithms can largely improve the performance of the linear detectors (LDs). However, there are two problems involved in the LR-aided detection algorithms. One is that, the reduced basis is still not orthogonal, and most existing LR-aided algorithms devote to find a near...
In this work, a transmission scheme that combines multi-layer multi-rate (MLMR) coding with quasi-orthogonal space-time block coding (QO-STBC) is proposed. Firstly, the proposed QO-STBC codewords set unequal diversity orders for different transmitted spatial data layers. Then, different spatial data layers are protected by different-rate channel codes with the aim of achieving the same post-decoding...
Spectrally Efficient Frequency Division Multiplexing (SEFDM) is a non-orthogonal multi-carrier communication technique that can pack more sub-carriers than Orthogonal Frequency Division Multiplexing (OFDM) for a given bandwidth. In this paper, we propose a hybrid soft Iterative Detection (ID) together with Fixed Sphere Decoding (FSD) for QAM modulation schemes from 4QAM to 16QAM. In terms of 4QAM,...
Intensity noise (IN) or phase induced intensity noise (PIIN) is the key limiting factor of the performance in spectral amplitude coding optical code division multiple access (SAC OCDMA) systems. The PIIN can be mitigated in SAC OCDMA by splitting the signals and detecting each signal by a different photodiode if the independence between the split signals can be achieved. In this paper, we derive the...
Different detection technique approach in wireless communication for multi input multi output (MIMO) systems at last ten decades. Lattice reduction aided detectors are also use extensively in MIMO systems. These detectors are introduce and work on the traditional algorithm which was originally base on reducing real lattice bases. In this paper, we use complex lattice reduction processing in dual basis...
In this paper, physical-layer network coding (PNC) aided bi-directional cooperative relay strategies are proposed for four-node transmitted reference pulse cluster (TRPC) ultrawideband (UWB) systems, which can improve the network throughput and accomplish information exchange within two time slots instead of four. First, we develop a new detector and a link quality indicator (LQI) at the relay side...
In this paper, we propose a complexity reduced soft bit estimation for iterative multiple-input multiple-output (MIMO) system with linear order of complexity. A maximum likelihood (ML) detection achieves the maximum performance, but its complexity increases exponentially by the number of antennas and modulation orders. In this paper, we propose an efficient soft bit estimation method for iterative...
This paper presents a 10 Gbps loss of signal (LOS) detector for high-speed AC-coupled serial transceivers. The detector is designed in 28nm CMOS and is capable of operating with a 29.5mV internal eye opening and a 67mV external eye opening at the input pads. It consumes 69uW from a 0.9V supply at 10 Gbps and properly asserts an LOS state in 6.8 nsec. A novel comparator topology, which is a part of...
Using meta-heuristic algorithms, such as harmony search (HS) algorithms are commonly used in many engineering fields. In this paper, we proposed a novel multiuser detector (MUD) for direct sequence-code division multiple access (DS-CDMA) systems. The detector is based on one of the HS algorithm versions called global-best harmony search (GHS) algorithm. The GHS algorithm is easy to be applied in DS-CDMA...
In this paper, two near-optimal detectors based on the convex optimization algorithm are proposed for multiuser detection (MUD) in the ultra-wide bandwidth (UWB) systems. The first detector performs semidefinite relaxation (SDR) to approximate the optimum multiuser detection (OMD) which is a nondeterministic polynomial time hard (NP-hard) problem. When the cutting planes generation algorithm is employed...
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