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Differential space-time coding techniques and MIMO

Song, Lingyang · OpenGrey (Institut de l'Information Scientifique et Technique) · 2006

Cited by 0

Differential Diversity-Embedding Space Time Block Coding

Payam Rabiei, Naofal Al‐Dhahir · 2006

Diversity-embedding space time block coding (DE- STBC) introduced in enables unequal error protection (UEP) using multiple transmit antennas. Even though these codes do not require channel state information (CSI) at the transmitter, they do need it at the receiver for decoding. A differential scheme is proposed in this paper to eliminate the need for channel estimation at the receiver which is especially costly with multiple transmit and receive antennas. Since most previously proposed differential schemes in the literature are based on orthogonal STBC, they are not applicable to the non-orthogonal family of DE-STBC considered in this paper.

Cited by 3

Differential Space-Time-Doppler Coding over Time-Selective Channels

Zhao Li · 2008

Differential encoding is known to simplify receiver implementation because it by-passes channel estimation.Relying on a basis expansion model for time-selective channels,we derive a new differential space-time-doppler modulation scheme for systems that are equipped with an arbitrary number of transmit and receive antennas and operate in time-selective channels.The proposed DSTD modulator consists of a concatenating spectral encoder,differential encoder and OFDM modulator that offer full spatio-doppler diversity and significant coding gain.A unitary structure is imposed on the differential encoder to admit linear,decoupled maximum likelihood(ML) detection in space and time. Simulation results show that the proposed! DSTD codes achieve higher diversity gain in time-selective channels than some existing differential schemes.

Cited by 0

Beamforming, Doppler compensation, and differential space-time coding

Mary Ann Ingram, Kuo-Hui Li, Anh Van Nguyen et al. · 2002

We consider the design of two beams, formed at the base station, that will serve as the two channels for differential space-time block coding in a high-mobility outdoor scenario. The mobile is assumed to have one omnidirectional antenna. In one approach, we consider selecting assuming no interference, the two most powerful beams produced by an RF beamformer. In the other approach, we make a compromise between power and Doppler spectrum partitioning. One channel is a beam that points directly at the mobile. The other beam is the difference of left and right beams, symmetric about the mobile. These left and right beams are Doppler compensated prior to forming their difference. Using computer simulation, we find that selecting beams based on power is more effective than selecting beams based on Doppler partitioning. We also find that using the two most powerful beams formed from eight antenna elements yields 7 dB and 8 dB SNR improvements, at 1.9 GHz and 5.8 GHz, respectively, relative to spatial diversity with two omnidirectional antennas.

Cited by 1

Serial and parallel concatenated differential space-time coding

Yi Yao, M.M.K. Howlader · 2003

We propose two types of turbo differential space-time coding, namely serial and parallel concatenated structures. In serial structure, a convolutional encoder is followed by a differential space-time encoder, while in parallel structure, two identical differential space-time encoders are concatenated in parallel. The encoding and iterative decoding process is thoroughly studied, and the improved performance at low SNR is demonstrated and compared via simulations.

Cited by 5

A new differential space-time block coding scheme

Xun Shao, Jinhong Yuan · 2003

Most existing space-time coding schemes rely heavily on accurate channel estimation at the receiver., which is a difficult task in rapidly fading environment. The previous Tarokh and Jafarkhani (see IEEE Journal on Selected Areas in Comm., vol.18, no.7, p.1169-1174, 2000) differential space-time block code (DSTBC) suffers from the signal constellation expansion for QPSK and 8PSK modulation. We present a new differential space-time block coding scheme without constellation expansion. This is achieved by choosing differential coefficients appropriately in the signal mapping. The new scheme can be decoded by a Viterbi decoder. More importantly, it provides a differential coding gain of 1 dB-1.5 dB due to the redundancy introduced in the differential coding and it is only 2 dB away from the coherent space-time block codes.

Cited by 2

Differential distributed space-time coding with imperfect synchronization

M. R. Avendi, Sina Poorkasmaei, Hamid Jafarkhani · eScholarship (California Digital Library) · 2014

© 2014 IEEE. Differential distributed space-time coding (D-DSTC) has been considered to improve both diversity and data-rate in cooperative communications in the absence of channel information. However, conventionally, it is assumed that relays are perfectly synchronized in the symbol level. In practice, this assumption is easily violated due to the distributed nature of the relay networks. This paper proposes a new differential encoding and decoding process for D-DSTC systems with two relays. The proposed method is robust against synchronization errors and does not require any channel information at the destination. Moreover, the maximum possible diversity and symbol-by-symbol decoding are attained. Simulation results are provided to show the performance of the proposed method for various synchronization errors and the fact that our algorithm is not sensitive to synchronization error.

Cited by 5

Cyclic Algebras for Noncoherent Differential Space–Time Coding

Frédérique Oggier · IEEE Transactions on Information Theory · 2007

We investigate cyclic algebras for coding over the differential noncoherent channel. Cyclic algebras are an algebraic object that became popular for coherent space-time coding, since it naturally yields linear families of matrices with full diversity. Coding for the differential noncoherent channel has a similar flavor in the sense that it asks for matrices that achieve full diversity, except that these matrices furthermore have to be unitary. In this work, we give a systematic way to find infinitely many unitary matrices inside cyclic algebras, which holds for all dimensions. We show how cyclic algebras generalize previous families of unitary matrices obtained using the representation of fixed-point-free groups. As an application of our technique, we present families of codes for three and four antennas that achieve high coding gain.

Cited by 21

Differential Distributed Space-Time Coding with Imperfect Synchronization

Avendi, M. R., Poorkasmaei, Sina, Jafarkhani, Hamid · arXiv (Cornell University) · 2014

Differential distributed space-time coding (D-DSTC) has been considered to improve both diversity and data-rate in cooperative communications in the absence of channel information. However, conventionally, it is assumed that relays are perfectly synchronized in the symbol level. In practice, this assumption is easily violated due to the distributed nature of the relay networks. This paper proposes a new differential encoding and decoding process for D-DSTC systems with two relays. The proposed method is robust against synchronization errors and does not require any channel information at the destination. Moreover, the maximum possible diversity and symbol-by-symbol decoding are attained. Simulation results are provided to show the performance of the proposed method for various synchronization errors and the fact that our algorithm is not sensitive to synchronization error.

Cited by 0Open access

Distributed Differential Space-Time Coding for Broadband Cooperative Networks

Sami Muhaidat, P. Ho, Murat Uysal · 2009

In this paper, we investigate distributed differential space-time block coding (STBC) for cooperative communications over frequency-selective fading channels. We carefully exploit the unitary structure of the orthogonal STBC to design a low complexity differential STBC receiver for multi-carrier broadband cooperative networks. We consider amplify-and-forward relaying and assume a single-relay scenario. Under the assumption of perfect power control for the relay terminal and high signal-to- noise ratio for the underlying links, our performance analysis demonstrates that the considered scheme is able to exploit fully the spatial diversity. We further present Monte Carlo simulation results to confirm our analytical observations.

Cited by 14

LETTER QPSK Differential Space Time Coding on Different Unitary

Matrices Sets · 2006

SUMMARY This letter investigates a distinct set of complex unitary matrices for differential space time coding by using QPSK modulation. The numerical results show that the properly selection of the initial transmission matrix and the set of unitary matrices can efficiently improve the bit error rate (BER) performance, especially for the antennas correlated fading channel. The computer simulations are evaluated over slow and fast Rayleigh fading channels. key words: space time coding, unitary matrices, QPSK, Rayleigh fading 1.

Cited by 0

Multiple-Symbol Differential Detection for Distributed Space-Time Coding

M. R. Avendi, Ha H. Nguyen, Quoc-Tuan Nguyen · arXiv (Cornell University) · 2014

Differential distributed space-time coding (D-DSTC) technique has been considered for relay networks to provide both diversity gain and high throughput in the absence of channel state information. Conventional differential detection (CDD) or two-symbol non-coherent detection over slow -fading channels has been examined and shown to suffer 3-4 dB loss when compared to coherent detections. Moreover, it has also been shown that the performance of CDD severely degrades in fast-fading channels and an irreducible error floor exists at high signal-to-noise ratio region. To overcome the error floor experienced with fast-fading, a nearly optimal "multiple-symbol" differential detection (MSDD) is developed in this paper. The MSDD algorithm jointly processes a larger window of received signals for detection and significantly improves the performance of D-DSTC in fast-fading channels. The error performance of the MSDD algorithm is illustrated with simulation results under different fading scenarios.

Cited by 0Open access

Gallager’s random coding exponent for differential space time modulation

Siddharth K. Srinivasan · Open Collections · 2010

In this thesis, we study differential space-time modulation with multiple transmit and receive antennas over a frequency non-selective block fading channel in the absence of channel state information (CSI) at both the transmitter and the receiver. We focus on the analysis of the random coding exponent proposed by Gallager for such spacetime channels employing differential modulation with finite signal sets, and consider multiple symbol differential detection (MSDD) with an observation window size N. The underlying principle of MSDD is to utilize an increased observation window of N > 2 consecutively received space-time samples to yield decision variables on N - 1 spacetime data symbols. We thus take into account the channel memory, and can improve power efficiency over conventional differential detection, which employs N = 2. We extend previous work for a similar setup, in that we consider channels where the fading coherence interval is different from the MSDD observation window N, and can be arbitrary with L independent fading realizations per coding frame. We analyze the effect of arbitrary fading coherence intervals on the random coding exponent, and therefore analyze the achievable performance of coded transmission over block fading channels with low to moderate code lengths, i.e. with decoding delay constraints. In this context we also analyze space-time transmission systems with spatial correlation between antennas. Such an analysis allows for a fair comparison of DSTM with MSDD where the window size may vary but the coded diversity remains fixed. We also devise upper and lower bounds and approximations for the random coding exponent, which allows us to not only bound the achievable performance of such space-time systems but also allows for efficient numerical evaluation of the random coding exponent by limiting the search space for the metric calculation. To this end, we make use of tree-search based sphere decoding algorithms for efficient decoding, and along with novel stopping criteria to control the accuracy of the approximation and correspondingly the computational complexity, we apply these sphere decoders for a reduction in complexity cost upto many orders of magnitude. The presented numerical results provide useful information on the performance of coded differential space-time transmission for short to moderate code lengths.

Cited by 0Open access

Super-orthogonal differential space-time trellis coding and decoding

Dong Wang, Xiang‐Gen Xia · IEEE Journal on Selected Areas in Communications · 2005

In this paper, a differential space-time trellis-coded scheme based on super-orthogonal space-time trellis codes (SOSTTCs) is proposed. It achieves full diversity and provides an improved coding gain. Based on the per-survivor processing (PSP) technique, a low-complexity suboptimal differential decoder is developed. In slow fading channels, it can approach the performance of SOSTTC with coherent decoding. Furthermore, in time-varying channels, a bank of recursive least square (RLS) type channel predictors are incorporated into the Viterbi decoder to track the channel variance and the RLS predictors do not need training data and channel statistics. The performance analysis is given. Simulation results are presented to illustrate our analytical results and they show that our scheme can achieve a good performance in both slow fading and time-varying fading channels with modest complexity.

Cited by 5

Antenna Subset Selection with Differential Space-Time Block Coding

Seyed Aidin Bassam, M. K. · IEEE Vehicular Technology Conference · 2006

This paper investigates the employment of antenna subset selection in differential space-time block codes (STBC) over Rayleigh and Rician slow fading channels. We assume the transmission of orthogonal space-time block codes specifically Alamouti codes. Our proposed antenna subset selection chooses the antenna set that maximizes the channel Frobenius norm. The simulation results show that the proposed method improves the system performance. The simulation results show that our proposed selection algorithm leads to diversity and power gains.

Cited by 1

Differential distributed space-time coding based on Cayley codes

Frédérique Oggier, Emmanuel Lequeu · 2008

We propose a coding strategy for wireless relay networks with no channel information based on Cayley differential unitary codes. While satisfying the requirements for differential distributed space-time coding, our scheme furthermore inherits of the advantages of Cayley codes, namely high rate, efficient encoding, and a linearized sphere decoder.

Cited by 4

Double differential space-time block coding for time-selective fading channels

Zhiqiang Liu, Georgios B. Giannakis, B.L. Hughes · IEEE Transactions on Communications · 2001

Most existing space-time coding schemes assume time-invariant fading channels and offer antenna diversity gains relying on accurate channel estimates at the receiver. Other single differential space-time block coding schemes forego channel estimation but are less effective in rapidly fading environments. Based on a diagonal unitary matrix group, a novel double differential space-time block coding approach is derived in this paper for time-selective fading channels. Without estimating the channels at the receiver, information symbols are recovered with antenna diversity gains regardless of frequency offsets. The resulting transceiver has very low complexity and is applicable to an arbitrary number of transmit and receive antennas. Approximately optimal space-time codes are also designed to minimize bit error rate. System performance is evaluated both analytically and with simulations.

Cited by 103

Differential space-time coding with offset quadrature phase-shift keying

A.L. Anderson, J.R. Zeidler, Michael A. Jensen · 2005

Differential space-time coding (DSTC) has been well established as a precoding technique that allows maximum likelihood detection of the received symbols without requiring knowledge of channel state information. This type of detection is useful for highly time-varying channels where the resulting cost of channel estimation is high. However, to date, this approach has not been developed for the commonly-used offset modulations that offer improved spectral performance in the presence of nonlinear transmit power amplifiers. This paper illustrates modifications to the DSTC detection strategy for offset quadrature phase shift keying. Furthermore, it is shown that while traditional DSTC achieves a reduced transmission rate, the combination with offset modulation allows full rate transmission if desired.

Cited by 2

A new high-rate differential space-time block coding scheme

Naofal Al‐Dhahir · IEEE Communications Letters · 2003

A new high-rate differential space-time transmission scheme based on spatial multiplexing of Alamouti-encoded information streams is developed. At the receiver, joint space-time differential interference cancellation and decoding is performed, realizing diversity and rate gains, without requiring channel knowledge or bandwidth expansion. Our focus is on the case of two information streams with two transmit antennas per stream on flat-fading channels for simplicity. However, using previously published techniques, the development readily extends to more than two information streams, to more than two transmit antennas per stream, and to frequency-selective channels.

Cited by 16

Multiple-Symbol Differential Detection for Unitary Space-Time-Frequency Coding

Ziyan Jia, Shiro Handa, Fumihito Sasamori et al. · 2008

In this paper, multiple-symbol differential detection (MSDD) is applied for differential unitary space-time- frequency coding (DUSTFC) scheme over frequency selective fading multiple-input multiple-output (MIMO) channels to compensate for the performance loss of conventional differential detection comparing with coherent detection. The decision metrics of time and frequency domain MSDD for DUSTFC are derived by considering the time and frequency domain fading autocorrelation respectively. Simulation results demonstrate that extending the observation interval of MSDD can effectively lower the error floors for DUSTFC schemes coded on both time and frequency domain.

Cited by 2