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Iterative receivers for SFBC-OFDM systems with adaptive training scheme
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作者 井雅 徐晓东 +1 位作者 陈明 程时昕 《Journal of Southeast University(English Edition)》 EI CAS 2005年第2期127-131,共5页
This paper considers the design of iterative receivers for space-frequencyblock-coded orthogonal frequency division multiplexing (SFBC-OFDM) systems in unknown wirelessdispersive fading channels. An iterative joint ch... This paper considers the design of iterative receivers for space-frequencyblock-coded orthogonal frequency division multiplexing (SFBC-OFDM) systems in unknown wirelessdispersive fading channels. An iterative joint channel estimation and symbol detection algorithm isderived. In the algorithm, the channel estimator performs alternately in two modes. During thetraining mode, the channel state information (CSI) is obtained by a discrete-Fourier-transform-basedchannel estimator and the noise variance and covariance matrix of the channel response is estimatedby the proposed method. In the data transmission mode, the CSI and transmitted data is obtainediteratively. In order to suppress the error propagation caused by a random error in identifyingsymbols, a simple error propagation detection criterion is proposed and an adaptive training schemeis applied to suppress the error propagation. Both theoretical analysis and simulation results showthat this algorithm gives better bit-error-rate performance and saves the overhead of OFDM systems. 展开更多
关键词 space-frequency block-coded orthogonal frequency division multiplexing(SFBC-OFDM) iterative receiver channel estimation adaptive training scheme
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ITERATIVE RECEIVER FOR OFDM SYSTEMS BASED ON SEMI-BLIND CHANNEL ESTIMATION
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作者 Jing Ya Xu Xiaodong Chen Ming Cheng Shixin 《Journal of Electronics(China)》 2007年第2期163-166,共4页
In this paper we propose two iterative algorithms of joint channel estimation and symbol detection for Orthogonal Frequency Division Multiplexing (OFDM) systems. In which, superimposed pilot scheme is adopted and an i... In this paper we propose two iterative algorithms of joint channel estimation and symbol detection for Orthogonal Frequency Division Multiplexing (OFDM) systems. In which, superimposed pilot scheme is adopted and an initial Channel State Information (CSI) is obtained by employing a first-order statistic. In each subsequent iteration, we propose two algorithms to update the CSI. The Mean Square Error (MSE) of channel estimation and Bit Error Rate (BER) performance are given and simulation results demonstrate that the iterative algorithm using method B has good perform-ance approaching the ideal condition. 展开更多
关键词 Orthogonal Frequency Division Multiplexing (OFDM) iterative receiver Channel estimation Maximum A Posteriori (MAP) probability decoder
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SAGE based iterative receiver for joint synchronization and channel estimation in uplink MIMO-OFDMA systems
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作者 JIANG Zheng QIN Xiao-fang ZHANG Xin CHANG Yong-yu 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2008年第3期100-104,共5页
A new Turbo iterative receiver structure is proposed for the uplink multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA) systems. The space-alternating generalized expectation-ma... A new Turbo iterative receiver structure is proposed for the uplink multiple-input multiple-output orthogonal frequency division multiple access (MIMO-OFDMA) systems. The space-alternating generalized expectation-maximization (SAGE) algorithm is naturally embedded in the framework of iterative receiver to perform synchronization and detection usin~ the Turbo detector outputs. In each iteration, the expectation step intends to remove the multiple access interference (MAI) caused by other asynchronous users, and the maximization step is utilized to estimate the required parameters (i.e., timing offset, carrier frequency offset, channel state information, etc.) sequentially for each user. Simulation results show that the proposed algorithm can approach the performance of ideal receiver closely, while the processing complexity is rather lower than the conventional detectors. 展开更多
关键词 SAGE iterative receiver SYNCHRONIZATION channel estimation
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Channel aware receiver for next generation wireless communication system
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作者 MUHAMMAD Asim ASFANDYAR Khan +1 位作者 JAVED Iqbal Bangash ABDULLAH Khan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第7期2131-2139,共9页
We consider an iterative phase synchronization scheme based on maximum a posteriori probability algorithm.In classical approaches,the phase noise estimation model considers one sample per symbol at the channel and rec... We consider an iterative phase synchronization scheme based on maximum a posteriori probability algorithm.In classical approaches,the phase noise estimation model considers one sample per symbol at the channel and receiver.However,information theoretic studies suggested use of more than one sample per symbol at the channel and receiver for achieving higher performance.In this article,a soft-information aided iterative receiver is derived,which uses off-the-shelf blocks for detection and demodulation by keeping the complexity of the receiver acceptable.We consider here two samples per symbols at the channel and receiver in a pragmatic paradigm.It is shown that phase noise estimation can be significantly improved at the expense of modest processing overhead.Simulation results are presented for low-density parity check coded quadrature amplitude modulations.Our results show a significant performance improvement for strong phase noise values compared to classical receiver approaches. 展开更多
关键词 phase noise channel iterative receiver multi-sample LDPC coded modulations
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Polar Coded Iterative Multiuser Detection for Sparse Code Multiple Access System 被引量:1
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作者 Hang MU Youhua Tang +3 位作者 Li Li Zheng Ma Pingzhi Fan Weiqiang Xu 《China Communications》 SCIE CSCD 2018年第11期51-61,共11页
Polar coded sparse code multiple access(SCMA) system is conceived in this paper. A simple but new iterative multiuser detection framework is proposed, which consists of a message passing algorithm(MPA) based multiuser... Polar coded sparse code multiple access(SCMA) system is conceived in this paper. A simple but new iterative multiuser detection framework is proposed, which consists of a message passing algorithm(MPA) based multiuser detector and a soft-input soft-output(SISO) successive cancellation(SC) polar decoder. In particular, the SISO polar decoding process is realized by a specifically designed soft re-encoder, which is concatenated to the original SC decoder. This soft re-encoder is capable of reconstructing the soft information of the entire polar codeword based on previously detected log-likelihood ratios(LLRs) of information bits. Benefiting from the soft re-encoding algorithm, the resultant iterative detection strategy is able to obtain a salient coding gain. Our simulation results demonstrate that significant improvement in error performance is achieved by the proposed polar-coded SCMA in additive white Gaussian noise(AWGN) channels, where the performance of the conventional SISO belief propagation(BP) polar decoder aided SCMA, the turbo coded SCMA and the low-density parity-check(LDPC) coded SCMA are employed as benchmarks. 展开更多
关键词 iterative multiuser receiver polarcode sparse code multiple access (SCMA)
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Multi-User Connection Performance Assessment of NOMA Schemes for Beyond 5G 被引量:4
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作者 Baoxi Wang Chunlin Yan +1 位作者 Wei Liu Hailin Zhang 《China Communications》 SCIE CSCD 2020年第12期206-216,共11页
Non-orthogonal multiple access(NOMA)is proved to be useful to satisfy the requirements of beyond 5th generation such as massive multi-user connection.Here we compare the performances of two NOMA schemes:low code rate ... Non-orthogonal multiple access(NOMA)is proved to be useful to satisfy the requirements of beyond 5th generation such as massive multi-user connection.Here we compare the performances of two NOMA schemes:low code rate spreading(LCRS)scheme and interleaver division multiple access(IDMA)scheme.It is found that LCRS is superior to IDMA when number of users is small due to coding gain achieved.While IDMA is preferred when number of users is high because repetition applied in IDMA can suppress multi-user interference effectively.And interleaver is important in IDMA for randomizing the interference.Also,this paper evaluates the impact of channel decoder.It is observed that Log-MAP decoder has much better performance than that of Max-Log-MAP when number of users is large.Thus,it is recommended to use Log-MAP decoder in NOMA in high user overloading case.We also compared the performance of NOMA by using different type of channel codes.We find that NOMA using specific convolutional code has a better performance than that of using specific LDPC code when number of users is high. 展开更多
关键词 NOMA multi-user connection LCRS IDMA iterative receiver channel coding
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COMBINED TRANSMIT ANTENNA SELECTION AND DETECTION OVER SPATIAL CORRELATED MIMO SYSTEMS 被引量:2
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作者 Meng Qingmin Hua Jingyu +1 位作者 You Xiaohu Zhuang Xiangyang 《Journal of Electronics(China)》 2007年第6期732-739,共8页
In this paper a method that combines transmit antenna selection and reduced-constellation detection in spatially correlated Multi-Input Multi-Output (MIMO) fading channels is presented. To mitigate the performance d... In this paper a method that combines transmit antenna selection and reduced-constellation detection in spatially correlated Multi-Input Multi-Output (MIMO) fading channels is presented. To mitigate the performance degradation caused by the use of antenna selection that is based on correlation among columns, an iterative receiver scheme that uses only a subset of the constellation points close to the expected symbol vahle estimated in the previous iteration is proposed. The size of the subset can adapt to the maximum correlation of the sub-matrix after the simple antenna selection. Furthermore, the error rate performance of the scheme under linear Miniinutn Mean Square Error (MMSE) or Ordered Successive Interference Cancellation (OSIC) for the first run detection and different interleaver lengths is investigated while the transnlit antenna selection is considered. The simulation results show a significant advantage both for implementation complexity and for error rate performance under a fixed data rate. 展开更多
关键词 Multi-Input Multi-Output (MIMO) Antenna selection CORRELATION Reduced-complexity detection method iterative receiver
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EXIT analysis of M-algorithm based MIMO detectors and LDPC code design optimization 被引量:9
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作者 YOU MingHou1,2, TAO XiaoFeng1,2, CUI QiMei1,2 & ZHANG Ping1,2 1 Wireless Technology Innovation Institute, Beijing University of Posts and Telecommunications, Beijing 100876, China 2 Key Laboratory of Universal Wireless Communications, (Beijing University of Posts and Telecommunications), Ministry of Education, Beijing 100876, China 《Science in China(Series F)》 2009年第12期2248-2258,共11页
This paper investigates joint design and optimization of both low density parity check (LDPC) codes and M-algorithm based detectors including iterative tree search (ITS) and soft-output M-algorithm (SOMA) in mul... This paper investigates joint design and optimization of both low density parity check (LDPC) codes and M-algorithm based detectors including iterative tree search (ITS) and soft-output M-algorithm (SOMA) in multiple-input multiple-output (MIMO) systems via the tool of extrinsic information transfer (EXIT) charts. First, we present EXIT analysis for ITS and SOMA. We indicate that the extrinsic information transfer curves of ITS obtained by Monte Carlo simulations based on output log-likelihood rations are not true EXIT curves, and the explanation for such a phenomenon is given, while for SOMA, the true EXIT curves can be computed, enabling the code design. Then, we propose a new design rule and method for LDPC code degree profile optimization in MIMO systems. The algorithm can make the EXIT curves of the inner decoder and outer decoder match each other properly, and can easily attain the desired code with the target rate. Also, it can transform the optimization problem into a linear one, which is computationally simple. The significance of the proposed optimization approach is validated by the simulation results that the optimized codes perform much better than standard non-optimized ones when used together with SOMA detector. 展开更多
关键词 MIMO systems iterative receiver LDPC codes code optimization EXIT charts M-ALGORITHM
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Recent progress in Bistatic SAR with illuminators of opportunity
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作者 ZENG Tao ZHANG Tian +1 位作者 TIAN Wei Ming HU Cheng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第12期1965-1967,共3页
Bistatic SAR(Bi SAR)with illuminators of opportunity is a kind of flexible SAR system that consists of non-cooperative transmitters and a stationary or moving receiver,as Figure 1shows.In recent years,notable effort... Bistatic SAR(Bi SAR)with illuminators of opportunity is a kind of flexible SAR system that consists of non-cooperative transmitters and a stationary or moving receiver,as Figure 1shows.In recent years,notable efforts have been made to promote the development of this kind of system.Progress regarding Bi SAR with navigation satellites as transmitters before 2015,including the related theory and practice,has been well reviewed by Antoniou et al.and can be referred from[1].This paper reviews some of the progress in 2015and 2016,including novel signal processing approaches,advanced Bi SAR system configurations and potentially 展开更多
关键词 opportunity stationary receiver navigation potentially cooperative iterative Figure subsidence utilized
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