In this paper, we present a low-complexity algorithm for detection in high-rate, non-orthogonal space-time block coded (STBC) large-multiple-input multiple-output (MIMO) systems that achieve high spectral efficiencies of the order of tens of bps/Hz. We also present a training-based iterative detection/channel estimation scheme for such large STBC MIMO systems. Our simulation results show that excellent bit error rate and nearness-to-capacity performance are achieved by the proposed multistage likelihood ascent search (M-LAS) detector in conjunction with the proposed iterative detection/channel estimation scheme at low complexities. The fact that we could show such good results for large STBCs like 16×16 and 32×32 STBCs from Cyclic Division Algebras (CDA) operating at spectral efficiencies in excess of 20 bps/Hz (even after accounting for the overheads meant for pilot based training for channel estimation and turbo coding) establishes the effectiveness of the proposed detector and channel estimator. We decode perfect codes of large dimensions using the proposed detector. With the feasibility of such a low-complexity detection/channel estimation scheme, large-MIMO systems with tens of antennas operating at several tens of bps/Hz spectral efficiencies can become practical, enabling interesting high data rate wireless applications.

High-Rate Space–Time Coded Large-MIMO Systems: Low-Complexity Detection and Channel Estimation

Full-duplex wireless communication is becoming an important research area because of its potential for increasing spectral efficiency. The challenge of such systems lies in cancelling the self-interference. In this paper, we focus on the design of digital cancellation schemes and use them to supplement RF/analog cancellation techniques. The performance of digital cancellation is limited by the non-ideal characteristics of different subsystems in the transceiver, such as analog/digital converter (ADC), power amplifier (PA), and phase noise. It is first shown that given the pre-cancellation achieved by existing RF/analog techniques, the effects of ADC, phase noise, and sampling jitter are not the bottleneck in the system. Instead, the performance of conventional digital cancellation approaches are mainly limited by nonlinearity of the PA and transmit I/Q imbalance. In addition, the output SINR of the desired signal is limited because the estimation precision of the self-interference channel is affected by the desired signal. To overcome these issues, we propose a two-stage iterative self-interference cancellation scheme based on the output signal of the power amplifier. Analytical and simulation results reveal that the proposed cancellation scheme substantially outperforms existing digital cancellation schemes for full-duplex wireless communication systems.

An Investigation Into Baseband Techniques for Single-Channel Full-Duplex Wireless Communication Systems

A multiple input multiple output (MIMO) communication method using a codebook is provided The MIMO communication method may use one or more codebooks and the codebooks may change according to a transmission rank, a channel state of a user terminal, and/or a number of feedback bits The one or more codebooks may be adaptively updated according to a time correlation coefficient of a channel

Codebook design method for multiple input multiple output system and method for using the codebook

Presenting the new IEEE 802.16m standard, this is the first book to take a systematic, top-down approach to describing Mobile WiMAX and its next generation, giving detailed algorithmic descriptions together with explanations of the principles behind the operation of individual air-interface protocols and network components. Features: A systematic and detailed, top-down approach to the design of 4G cellular systems based on IEEE 802.16m and 3GPP LTE/LTE-Advanced technologies A systematic approach to understanding IEEE 802.16m radio access network and mobile WiMAX network architecture and protocols The first comprehensive technical reference on the design, development and performance evaluation of IMT-Advanced systems, including the theoretical background and design principles as well as implementation considerations About the author: The author, chief architect and technical lead of the IEEE 802.16m project at Intel Corporation, initiated and masterminded the development of the IEEE 802.16m standard and has been one of the leading technical drivers in its standardization process in IEEE. The author was also a leading technical contributor to the definition and development of requirements and evaluation methodology for the IMT-Advanced systems in ITU-R. Reflecting the author's 20+ years expertise and experience, the book provides an in-depth, systematic and structured technical reference for professional engineers, researchers, and graduate students working in cellular communication systems, radio air-interface technologies, cellular communications protocols, advanced radio access technologies for 4G systems, and broadband cellular standards. A systematic and detailed, top-down approach to the design of 4G cellular systems based on IEEE 802.16m and 3GPP LTE/LTE-Advanced technologiesA systematic approach to understanding IEEE 802.16m radio access network and mobile WiMAX network architecture and protocolsThe first comprehensive technical reference on the design, development and performance evaluation of IMT-Advanced systems, including the theoretical background and design principles as well as implementation considerations

Mobile WiMAX: A Systems Approach to Understanding IEEE 802.16m Radio Access Technology

In this contribution, a multi-user receiver for M- QAM MIMO-OFDM operating in time-varying and frequency-selective channels is derived. The proposed architecture jointly performs semi-blind estimation of the channel weights and noise inverse variance, serial interference cancellation and decoding in an iterative manner. The scheme relies on a variational message-passing approach, which enables a joint design of all these functionalities or blocks but the last one. Decoding is performed using the sum-product algorithm. This is in contrast to nowadays proposed approaches in which all these blocks are designed and optimized individually. Simulation results show that the proposed receiver outperforms in coded bit-error-rate a state-of-the- art iterative receiver of same complexity, in which all blocks are designed independently. Joint block design and, as a result, the fact that the uncertainty in the channel estimation is accounted for in the proposed receiver explain this better performance.

/pdf/variational-message-passing-for-joint-channel-estimation-and-1lhx7qher3.pdf

Variational Message-Passing for Joint Channel Estimation and Decoding in MIMO-OFDM

Signals transmitted through multiple-input multiple-output (MIMO) wireless channels buffer from multiple-access interference (MAI), multipath propagation and additive noise. Iterative multiuser algorithms mitigate these signal impairments. while offering a good tradeoff between performance and complexity. The receiver presented in this paper performs channel estimation. multiuser detection and decoding in an iterative manner. The estimation of the frequeucy selective. block-fading channel is initiated with the pilot symbols. In subsequent iterations. soft decisions of all the data symbols are used in an appropriate way to improve the channel estimates. This approach leads, to significant Improvement of the overall receiver performance, compared to other schemes. The bit-error-rate (BER) performance of the receiver is evaluated by simulations for different parameter setups. Copyright (C) 2004 AEI. (Less)

Iterative channel estimation and data detection in frequency-selective fading MIMO channels†

In this paper, we present a differential codebook precoding technique for MIMO spatial multiplexing systems. The proposed scheme updates the precoding matrix by multiplying the codebook matrix specified by the receiver to the previous precoding matrix. The codebook matrices are designed to include quasi-diagonal matrices for finer quantization of the channel. We analyze the capacity of the differential precoding scheme as well as existing precoding schemes by taking into account various practical aspects such as precoding update interval, feedback delay, and feedback error. Simulation results show that in a MIMO system with four transmit and two receive antennas, the proposed precoding scheme requires smaller codebook size by about 1 - 2 bits than the one-shot precoding scheme with Grassmannian codebook to achieve the same capacity level when the channel variation is relatively small. Finally, we show that the proposed precoding scheme provides similar throughput performance gain in MIMO-OFDM systems in frequency selective fading channels.

Differential Codebook MIMO Precoding Technique

This paper studies the computation of post-processing signal-to-interference plus noise ratio (SINR) for maximum likelihood detector (MLD) in multiple-input and multiple output (MIMO)-orthogonal frequency division multiplexing (OFDM) spatial multiplexing systems. We derive an effective post-MLD SINR for each spatial stream, which is computed as post minimum mean-squared error (MMSE) SINR plus gain factor, where the gain factor is adaptively computed based on the instantaneous channel and modulation format of interfering streams. The post-MLD SINR is then applied to modulation and coding scheme (MCS) selection in adaptive modulation and coding. Simulation results show that the MCS selection using proposed post-MLD SINR can achieve throughput performance close to that of the optimum approach, and considerable gain can be achieved over linear-MMSE receiver.

/pdf/effective-sinr-computation-for-maximum-likelihood-detector-5aglxm68fl.pdf

Effective SINR Computation for Maximum Likelihood Detector in MIMO Spatial Multiplexing Systems

A method called open loop cyclic delay diversity (CDD) precoding has recently become part of the standard for 3GPP Long-Term Evolution (LTE) cellular communications systems. CDD had previously been proposed as single stream diversity method for OFDM systems. The proposal in LTE is an extension to spatial multiplexing using so called large delay CDD. The purpose of this paper is twofold: First, we give two different interpretations of the CDD precoding scheme in LTE as beam switching and transformation of spatial diversity to frequency diversity. We then discuss the impact of the delay parameter in CDD precoding on the achievable rates and BER performance. It turns out that while the choice of large delay causes a capacity degradation in single stream CDD, the achievable rates in CDD based spatial multiplexing are robust to variations of the delay parameter. This is even true in correlated scenarios and when only a resource block of a few subcarriers is allocated to a specific user. However, in case of separate encoding of the spatial streams, large delay CDD precoding shows a BER advantage over small delay CDD precoding since the spatial diversity is transformed into frequency diversity among adjacent subcarriers and, hence, is easily picked up by the decoder. Finally, we give a performance comparison of open loop CDD based precoding and closed loop precoding in LTE. It is shown that for 2 transmit antenna systems, only little gain is achieved by the additional effort of closed loop precoding. Closed loop precoding shows substantial benefits over CDD based precoding only for a higher number of transmit antennas.

On the Parameter Choice for Cyclic Delay Diversity Based Precoding with Spatial Multiplexing

In this paper, we conduct performance comparison of rate compatible parallel concatenated convolutional code (PCCC) and serially concatenated convolutional code (SCCC) in additive white Gaussian noise (AWGN) and frequency selective fading channels. Series of computer simulation results show that the packet error rate (PER) performance of memory 2 SCCC is worse than that of memory 3 PCCC by 0.4-0.8dB at 10-2 PER after the sufficient number of decoding iterations, whereas the complexity of SCCC is lower than that of PCCC by about 39%. Increasing the memory length in SCCC does not lead to performance gain. On the other hand, reducing memory length in PCCC leads to significant performance degradation. However, reducing the number of iterations to half in PCCC leads to lower complexity than SCCC and still offers better PER performance than SCCC in terms of the required E b /N 0 for 10-2 PER. Therefore, PCCC can achieve better trade-off between complexity and performance than SCCC.

http://ieeexplore.ieee.org/iel5/4362242/4362243/04362405.pdf

Tetsushi Abe

Papers

Iterative channel estimation and data detection in frequency-selective fading MIMO channels†

Differential Codebook MIMO Precoding Technique

Effective SINR Computation for Maximum Likelihood Detector in MIMO Spatial Multiplexing Systems

On the Parameter Choice for Cyclic Delay Diversity Based Precoding with Spatial Multiplexing

A Comparison of Rate Compatible PCCC and SCCC for Next Generation Wireless Communication Systems