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The full potential of multiple-input multiple-output (MIMO) wireless technology can be achieved through iterative MIMO decoding with soft information. In iterative MIMO decoder, the complexity can be major obstacle for practical implementation. The soft interference cancellation-minimum mean squared error (SIC-MMSE) approach for detection is considered as a feasible approach due to its complexity-performance...
Low-density parity-check (LDPC) coded massive multiple-input and multiple-output (MIMO) scheme is getting increasingly popular and sophisticated in today's wireless communication systems, since it can highly improve the spectral efficiency, data rates, and error performance. In this paper, a novel iterative detection and decoding (IDD) method for LDPC-coded massive MIMO systems is proposed. Based...
A simple technique to design MIMO space-time block codes that achieve both diversity and rate gains is to stack spatial multiplexing (V-BLAST) and transmit diversity (Alam-outi) encoders; these are known as hybrid codes. We increase the spectral efficiency of a simple hybrid code with one V-BLAST layer and one Alamouti layer by using spatial modulation. In spatial modulation systems, information is...
A direct spread spectrum (DSS) communication system is presented, which uses optimized spread spectrum sequence (SSS) and adaptive soft-iteration (Turbo) equalization (ASIE). The scheme using multiple receiver is similar to MIMO systems. The average cross-correlation of SSS is regarded as a critical factor to search optimized sequences used in under water acoustic (UWA) multi-access burst communication...
In this work we present construction of Space Time Block Codes (STBC) from Abelian codes. A well known Eisenstein-Jacobi rank preserving map is applied to map the codeword matrix symbols to symbols in the complex plane. We then propose an NT × NR MIMO (multiple input, multiple output) communication system employing the constructed STBC. An analysis on the receiver (decoder) computational complexity...
In this paper, an accurate QR decomposition based link level performance abstraction technique for a multi-input multi-output iterative receiver is proposed. The post-detection SNR values for an iterative receiver are estimated using QR decomposition of the channel matrix. The effect of channels on the received SNR is realized by scaling the signal in accordance with the leading diagonal elements...
In this paper, minimum MSE based interference alignment (IA) algorithm is developed for the interfering broadcast channel (IBC), which models the multi-cell downlink system, underlying cognitive radio, device-to-device and other scenarios. The IA precoders and decoders are computed to minimize the MSE. Cascade design is used for IA precoder design, where the first component precoder is obtained by...
Massive multiple-input multiple-output (MIMO) systems can achieve high data rates due to the large number of antennas at the base station when it serves a small number of users. However, deploying massive MIMO in current mobile networks faces a lot of practical issues such as limited physical space and power consumption. Packing large number of antennas in a limited physical space makes spatial correlation...
Sphere decoding (SD) is an efficient algorithm for Multiple-input Multiple-output (MIMO) digital communications. It has been showed to achieve near Maximum Likelihood (ML) performance with low complexity. However, the complexity of conventional SD algorithm is high under the specific environment. The performance and the computation complexity of SD algorithm is highly dependent on the initial choice...
The problem of high-rate space-time block code (STBC) design and transmission is studied in a large multiple-input multiple-output (MIMO) system in Rayleigh fading environment. One attractive feature of large MIMO system is that a huge amount of data can be transmitted from transmitter to the receiver/multiple users. In practical systems, channel state information (CSI) is not available for decoding...
Soft-input soft-output (SISO) sphere decoding is applied to multiple-input multi-output (MIMO) systems to offer good bit error rate (BER) performance but at high complexity. To reduce this computational complexity, we propose a novel hybrid enumeration strategy for such decoding that dynamically determines the candidate list; moreover, this strategy uses a new node enumeration based on concentric...
It is known that by extracting log-likelihood ratio (LLR) values from the received MIMO signals, a MIMO detector is able to exchange a posteriori soft information with a channel decoder to improve the error performance. A minimum mean-square error with parallel interference cancellation (MMSE-PIC) detector is considered to be a practical MIMO detector, but the computational complexity for the LLR...
The multiple-input multiple-output (MIMO) technology can make full use of spectrum and increase the communication throughput. In the coded MIMO system, the main challenge of soft detection is to efficiently generate the loglikelihood ratios (LLR) values for channel decoder. The exact maximum a posteriori (MAP) probability detection can guarantee the optimal performance, but its realization is difficult...
The capacity region of a two-transmitter Gaussian multiple access channel (MAC) under average input power constraints is studied, when the receiver employs a zero-threshold one-bit analog-to-digital converter (ADC). It is proved that the input distributions that achieve the boundary points of the capacity region are discrete. Based on the position of a boundary point, upper bounds on the number of...
This work presents the first integration of a message-passing detector (MPD) and a polar decoder. A soft-output MPD, which is essential to approach the channel capacity, is first proposed. Compared to the state-of-the-art design, the proposed MPD achieves a 6.9x higher throughput with 49% lower energy, despite the soft outputs. The proposed polar decoder achieves a 1.35x higher throughput with comparable...
One of the main challenges of communication in the absence of transmitter channel knowledge is codebook universality, i.e., the existence of a single codebook that guarantees a given rate for all channel states. We address this problem for a class of ergodic fading multiple-input multiple-output (MIMO) channels, whose fading distribution is not necessarily isotropic. It is shown that a universal codebook...
Lattice-reduction-aided decision-feedback equalization (LRA DFE) and successive integer forcing are MIMO detection schemes which combine the equalization in a suited basis with the principle of successive interference cancellation (SIC). To this end, the reduction algorithm not only has to find a suited basis, but it should also provide an optimized detection order for SIC: the V-BLAST ordering, known...
The BOX-LASSO is a variant of the popular LASSO that includes an additional box-constraint. We propose its use as a decoder in modern Multiple Input Multiple Output (MIMO) communication systems with modulation methods such as the Generalized Space Shift Keying (GSSK) modulation, which produces constellation vectors that are inherently sparse and with bounded elements. In that direction, we prove novel...
In this paper we present a flexible decoding kernel using K-best and iterative K-best algorithms. Using this decoding kernel, system designers can choose the alternative algorithms for their different applications. With one kernel, it supports multiple configurable antennas (2×2,4×4) and variable modulation schemes (QPSK,16-QAM). Using number of kernels supports 8×8 and 64-QAM. Using a 90-nm CMOS...
Space-time trellis codes (STTCs) combine channel coding and multiple-input multiple-output (MIMO) techniques to provide coding and diversity gains for wireless communication systems. The decoding complexity is extremely high because of the high density of branch metric calculations. Thus, this study presents a state-purging mechanism based on the T-algorithm to reduce the computational complexity...
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