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A low complexity M-algorithm based multiple-input multiple-output (MIMO) tree search algorithm with near maximum likelihood (ML) performance is proposed in this paper. Numerical examples show that our tree search algorithm is able to provide a significant performance gain over the MMSE detection. Based on this algorithm, a fully pipelined architecture is presented for the MIMO orthogonal frequency...
In this paper, a low-complexity soft-output QRD-M detection algorithm is proposed for high-throughput Multiple-input multiple-output (MIMO) systems. By employing novel expansion and sorting scheme, the proposed algorithm can greatly reduce the numbers of the fundamental operations during the tree search process, especially the comparison operations which play a key role in the QRD-M detector' computational...
In-Band On-Channe (IBOC) digital audio broadcasting (DAB) is a method of digital audio radio , which could transmit analog FM and digital audio simultaneously. However, due to the existence of fading and interference in FM bands, transmit capacity has reached its limitations for the bandwidth, thus, adding digital transmission in the crowded FM band is a challenging proposition. Diversity is one of...
Multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) is considered as candidates for future 3G/B3G broadband wireless services. In this paper a novel signal detection scheme based on Quantum Genetic Algorithm (QGA) is proposed for MIMO-OFDM systems. Quantum Genetic Algorithm (QGA) is based on the concept and principles of quantum computing, such as quantum bit and...
The current literature lacks the VLSI realization of high-order multiple-input-multiple-output (MIMO) detectors in the complex domain, which finds applications in advanced wireless standards such as WiMAX and Long Term Evolution (LTE) systems. In this paper, a novel modified complex K-Best algorithm and its VLSI implementation for a 4 × 4, 64QAM complex MIMO detector are proposed. The main contributions...
Ant colony optimization (ACO), inspired by the ants' foraging behavior, is one of the most recent techniques for solving optimization problems. We present an ACO based algorithm for symbol detection in multi-input multi-output (MIMO) system. Since symbol detection is an NP-hard problem so ACO is particularly attractive as ACO algorithms are one of the most successful strands of swarm intelligence...
Quantum Genetic Algorithm (QGA) is based on the concept and principles of quantum computing, such as quantum bit and superposition of states. Instead of binary, numeric, or symbolic representation, QGA uses a Q-bit, defined as the smallest unit of information, for the probabilistic representation and a Q-bit individual as a string of Q-bits. A Q-gate is introduced as a variation operator to drive...
In this work we study a two-user multiple antenna system under quasi-static fading employing a novel scheme that combines cooperation and iterative multiuser detection based on minimum mean square error estimation. We investigate three different receivers: a joint detector for the two users, a separate (per-user) detector, and a distributed matrix-Alamouti detector. We show that the separate detector...
A multi-port power amplifier (MPA) is a multi-input multi-output system that is capable of amplifying multiple input signals simultaneously by a set of shared power amplifiers without mutual interference. In a practical MPA, the component imperfections reduce the port isolation, which introduces leakage or cross-port interference. A patent-pending type-based calibration technique is studied in this...
This paper presents a simulation study that evaluated one optimal and several near-optimal algorithms for detecting 16-QAM and 64-QAM symbols in single-user MIMO receivers. The study is part of a larger project to develop efficient and near-optimal MIMO detection algorithms for high-order symbol constellations. Fouladi Fard's near-optimal detection algorithm differs from the conventional V-BLAST algorithm...
Coping with collisions is one of the biggest challenges in the design of MAC algorithms for wireless networks. Recent advances in MIMO communications have provided the possibility of decoding colliding packets. In this paper, we introduce a new MIMO cross-layer MAC/PHY design that is capable of combating collisions through the use of a multiple packet detection technique. Analytical and simulation...
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...
In this paper, we consider user selection criteria for various multiple input multiple output (MIMO) detectors to exploit the multiuser diversity. It is shown that the user selection criterion plays a crucial role in exploiting both multiuser and receive (or spatial) diversity. We also show that the maximum likelihood (ML) and even some low complexity suboptimal detectors (based on the lattice reduction...
This paper presents a novel detector implementation that takes advantage of instantaneous channel states by switching between Space-Time Coding (STC) and Spatial Multiplexing (SM) modes. For a fixed rate, the detector calculates whether the channel is better suited for SM or STC transmission. This decision can then be fed back to the transmitter via a low-rate feedback channel. The detector is designed...
It is well known that the order of the channel matrix columns has significant impact on a MIMO detector's performance in terms of the computational complexity, memory requirement, and/or the detection error rate. In our previous work, novel ordering schemes have been proposed to reduce the computational complexities and/or memory requirements of various maximum likelihood (ML) MIMO detectors. In this...
Recently, MIMO detectors which are based on Markov Chain Monte Carlo (MCMC) simulation techniques have been proposed as alternatives to, e.g., the well-known sphere detector. In this paper, we present a systematic analysis of the performance of MCMC detectors. We study the impact of several parameters such as the list size and the number of independently running chains. As a performance criterion,...
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 we introduce an innovative version of the recently proposed Layered ORthogonal lattice Detector (LORD). LORD is an attractive MIMO detection algorithm, which aims to approach the optimal Maximum-Likelihood (ML) detection performance with a reasonable complexity, quadratic in the number of transmitting antennas rather than exponential. LORD is also well suited to a hardware (e.g. ASIC...
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...
In the absence of exhaustive search and matrix inversion, this paper proposes a low complexity multi-input multi-output (MIMO) detector for coded systems based on the combination of maximal ratio combining (MRC) and minimum mean square error (MMSE) algorithm. The proposed scheme takes advantage of MMSE for the first iteration to guarantee reliable soft information derived from channel decoder. With...
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