Iterative MIMO Receivers Research Articles

Deep Learning Aided LLR Correction Improves the Performance of Iterative MIMO Receivers

Deep Learning Aided LLR Correction Improves the Performance of Iterative MIMO Receivers

Spread Unsourced Random Access With an Iterative MIMO Receiver

This work is dedicated to the unsourced random access (URA) with multiple-antenna receiver. We utilize a preamble-payload packet format where the preamble, selected from a pool shared between all active users, serves as a temporary activity detection identifier. The payload carries the main portion of the message data which is encoded for error correction, permuted, and scrambled. The compressed-sensing (CS) preamble receiver that estimates the active preambles and the respective user channels is followed by a payload receiver which performs several iterations of data and channel estimation and parallel interference cancellation. Our numerical and analytic results demonstrate that the presented system outperforms the related work in terms of the achievable numbers of active users and signal-to-noise ratios (SNR)s supported by the system.

A novel JFG detection-decoding approach of a vertical shuffle scheduling for iterative MIMO receivers with NB-LDPC codes

MIMO systems exploit multi-path propagation in a rich broadcast environment to improve throughput and performance of digital communication systems. The correspondent demappers require additional computational complexity. In this paper, a new detection-decoding approach based on vertical shuffle scheduling is proposed. Space exploration for the maximum likelihood detection is reduced to a dynamic region that surrounds the received symbol. Thus, a dynamic approach is proposed to detect the closest point of the channel observation without calculating all the candidate symbols in a constellation. In addition, a novel method based on EXIT chart study is proposed to find the sufficient number of neighboring points to search around a local minimum and then compute by recursion their Euclidean distances. Compared to the conventional Maximum Likelihood detector, the proposed algorithm allows a reduction in the computational complexity, in terms of number of multiplication, reaching 98%. The simulation results show that the proposed algorithm outperforms the state-of-the-art algorithms like MMSE, sphere decoding, DBTC and DaVinci codes.

Low-Complexity Progressive MIMO-OFDM Receiver for Underwater Acoustic Communication

Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) proves to be a better choice for high speed underwater acoustic (UWA) communication as it increases the data rate and solves the bandwidth limitation issue; however, at the same time, it increases the design challenges and complexity of the receivers. Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) are introduced in the received signal by the extended multipath and Doppler shifts along with different types of noises due to the noisy acoustic channel. Here we propose two iterative receivers: one is ICI unaware iterative MIMO-OFDM receiver, which uses a novel cost function threshold based soft information decision feedback method. The second one is ICI aware progressive iterative MIMO-OFDM receiver, which adapts and increases the progressions according to the level of ICI present in the received signal, while fully utilizing the soft information from the previous iterations, therefore reducing the complexity. Orthogonal Matching pursuit (OMP) channel estimation, low density parity check (LDPC) decoding and minimum mean square error (MMSE) equalization schemes are exploited by both the receivers. The proposed receivers are analyzed and compared with the standard Alamouti MIMO receiver as a reference and also compared with the non-iterative, basic turbo iterative and non-progressive iterative MIMO receivers. Simulations and experimental results prove the efficiency and effectiveness of the proposed receivers.

An Iterative MIMO Receiver Employing Virtual Channels with a Turbo Decoder for OFDM Wireless Systems

An Iterative MIMO Receiver Employing Virtual Channels with a Turbo Decoder for OFDM Wireless Systems

A comparison of iterative MIMO receivers under channel uncertainty

ABSTRACTThis work investigates iterative architectures for coded transmission over multiple input multiple output channels in the presence of channel uncertainty. Robust receivers that are less sensitive to the uncertainty are designed. The nature of iterative algorithms is especially suited to iterative decoding and channel estimation (ID&CE), which is a widely accepted means of dealing with imperfections in channel state information. ID&CE re‐estimates the channel in each iteration to deal with the uncertainty. The derived robust algorithm can be combined with ID&CE to yield significant performance gains as demonstrated by the simulation results. Copyright © 2011 John Wiley & Sons, Ltd.