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2008

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Iterative

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Full-Text Articles in Science and Technology Studies

A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping Jan 2008

A Low-Complexity Iterative Channel Estimation And Detection Technique For Doubly Selective Channels, Qinghua Guo, Li Ping

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we propose a low-complexity iterative joint channel estimation, detection and decoding technique for doubly selective channels. The key is a segment-by-segment frequency domain equalization (FDE) strategy under the assumption that channel is approximately static within a short segment. Guard gaps (for cyclic prefixing or zero padding) are not required between adjacent segments, which avoids the power and spectral overheads due to the use of cyclic prefix (CP) in the conventional FDE technique. A low-complexity bi-directional channel estimation algorithm is also developed to exploit correlation information of time-varying channels. Simulation results are provided to demonstrate the efficiency of …


Evolution Analysis Of Low-Cost Iterative Equalization In Coded Linear Systems With Cyclic Prefixes, Xiaojun Yuan, Qinghua Guo, Xiaodong Wang, Li Ping Jan 2008

Evolution Analysis Of Low-Cost Iterative Equalization In Coded Linear Systems With Cyclic Prefixes, Xiaojun Yuan, Qinghua Guo, Xiaodong Wang, Li Ping

Faculty of Engineering and Information Sciences - Papers: Part A

This paper is concerned with the low-cost iterative equalization/detection principles for coded linear systems with cyclic prefixes. Turbo frequency-domain-equalization (FDE) is applied to systems that may contain the joint effect of multiple-access interference (MAI), cross-antenna interference (CAI) and inter-symbol interference (ISI). We develop an SNK-variance evolution technique for the performance evaluation of the proposed systems. Numerical results in various channel environments demonstrate excellent agreement between the predicted and simulated system performance. © 2008 IEEE.


Low-Complexity Iterative Detection In Multi-User Mimo Isi Channels, Xiaojun Yuan, Qinghua Guo, Li Ping Jan 2008

Low-Complexity Iterative Detection In Multi-User Mimo Isi Channels, Xiaojun Yuan, Qinghua Guo, Li Ping

Faculty of Engineering and Information Sciences - Papers: Part A

We propose a low-cost detection strategy for multi-user multiple-input-multiple-output (MIMO) systems with inter-symbol interference (ISI). The cyclic prefix (CP) technique is assumed. The proposed detection algorithm is derived in a very concise manner based on some elegant properties of circulant matrices. We show that multi-user detection and equalization can be carried out jointly and efficiently. © 2007 IEEE.


Impact Of Signaling Schemes On Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo Jan 2008

Impact Of Signaling Schemes On Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

In this paper, we study the iterative detection problem for a coded system with multi-ary modulation. We show that, with iterative linear minimum-mean-square-error (LMMSE) detection, superposition coded modulation (SCM) can provide performance superior to that with other traditional signaling schemes used in trellis coded modulation (TCM) and bit-interleaved coded modulation (BICM). This finding provides a useful guideline for system design considering inter-symbol interference (ISI) and other forms of interference. Simulation results are provided to illustrate the efficiency of the iterative LMMSE detection with different signaling schemes. © 2008 IEEE.


Performance Analysis Of Multi-Ary Systems With Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo Jan 2008

Performance Analysis Of Multi-Ary Systems With Iterative Linear Minimum-Mean-Square-Error Detection, Li Ping, Jun Tong, Xiaojun Yuan, Qinghua Guo

Faculty of Engineering and Information Sciences - Papers: Part A

This paper is concerned with coded multi-ary systems over linear channels. Based on a semi-analytical evolution technique, the impact of signaling schemes on the performance of low-cost iterative linear minimum-mean-square-error (LMMSE) detection is studied. It is shown that superposition coded modulation (SCM) maximizes the output signal-to-noise ratio (SNR) of LMMSE detectors. Consequently, SCM may potentially outperform other conventional signaling schemes when LMMSE detectors are used. Numerical examples are provided to verify the theoretical analysis. © 2008 IEEE.