Education:

PhD. in Electrical & Computer Engineering, Dec. 2009

University of Utah, Salt lake city, UT

M.S in Electronic Engineering, April 2002

Beijing University of Aeronautics & Astronautics, Beijing, China

B.S. in Electrical Engineering, July 1998 (with highest honor)

Research Interests:

His research interests include MIMO/OFDM system, Turbo-like codes and LDPC codes, iterative decoding, Synchronization, channel equlization and estimation, cross layer design and other areas of wireless communication. and signal processing.

Publications:

Journal Papers

[3] Rong-Rong Chen and Ronghui Peng, Performance of Channel Coded Noncoherent Systems: Modulation Choice, Information Rate, and Markov Chain Monte Carlo Detection, IEEE Transactions on Communications, vol. 57, no. 10, pp. 2841-2845, Oct. 2009. Full Version

Abstract: This paper investigates performance of channel coded noncoherent systems over block fading channels. We
consider an iterative system where an outer channel code is serially concatenated with an inner modulation code amenable to noncoherent detection. We emphasize that, in order to obtain near-capacity performance, the information rates of modulation codes should be close to the channel capacity. For certain modulation codes, a single-input single-output (SISO) system with only one transmit antenna may outperform a dual-input and single-output (DISO) system with two transmit antennas. This is due to the intrinsic information rate loss of these modulation codes compared to the DISO channel capacity. We also propose a novel noncoherent detector based on Markov Chain Monte Carlo
(MCMC). Compared to existing detectors, the MCMC detector achieves comparable or superior performance at reduced complexity. The MCMC detector does not require explicit amplitude or phase estimation of the channel fading coefficient, which makes it an attractive candidate for high rate communication employing quadrature amplitude modulation (QAM) and for multiple antenna channels. At transmission rates of 1~1.667 bits/sec/Hz, the proposed SISO systems employing 16QAM and MCMC detection perform within 1.6-2.3 dB of the noncoherent channel capacity achieved by optimal input.

[4] Ronghui Peng and Rong-Rong Chen, Application of Nonbinary LDPC Cycle Codes to MIMO Channels, IEEE Transactions on Wireless Communications Vol. 7, no. 6, pp. 2020-2026, June., 2008.

Abstract: In this paper, we investigate the application of nonbinary low-density parity-check (LDPC) cycle codes over Galois field GF(q) to multiple-input multiple-output (MIMO) channels. Two types of LDPC coded systems that employ either joint or separate MIMO detection and channel decoding are considered, depending on the size of the Galois field and the modulation choice. We construct a special class of nonbinary LDPC cycle codes called the parallel sparse encodable (PSE) codes. The PSE code, consisting of a quasi-cyclic (QC) LDPC cycle code and a simple tree code, has the attractive feature that it is not only linearly encodable, but also allows parallel encoding which can reduce the encoding time significantly. We provide a systematic comparison between nonbinary coded systems and binary coded systems in both performance and complexity. Our results show that the proposed nonbinary system employing the PSE code outperforms not only the binary LDPC code specified in the 802.16e standard, but also the optimized binary LDPC code obtained using the EXIT chart methods. Through a detailed complexity analysis, we conclude that for the MIMO channel considered, the nonbinary coded systems achieve a superior performance at a receiver complexity that is comparable to that of the binary systems.

[5] Ronghui Peng and Rong-Rong Chen, Near optimal pre-equalization combining for MIMO HARQ system, Unpublished

[1] Y. Voronenko, V. Arbatov, C.R. Berger, Ronghui Peng, M. Pueschel, and F. Franchetti, Computer Generation of Platform-Adapted Physical Layer Software, SDR Forum Technical Conf. and Product Exhibition 2010. (Slides)

Abstract: In this paper, we describe a program generator for physical layer (PHY) baseband processing in a software-defined radio implementation. The input of the generator is a very high level platform-independent description of the transmitter and receiver PHY functionality, represented in a domain-specific declarative language called Operator Language (OL). The output is performance-optimized and platform-tuned C code with single-instruction multiple-data (SIMD) vector intrinsics and threading directives. The generator performs these optimizations by restructuring the algorithms for the individual components at the OL level before mapping to code. This way known compiler limitations are overcome. We demonstrate the approach and the excellent performance of the generated code on on the IEEE 802.11a (WiFi) receiver and transmitter PHY for all transmission modes.

[2] Salam Akoum, Ronghui Peng, Rong-Rong Chen and Behrouz Farhang-Boroujeny, Soft detection using constrained Markov Chain Monte Carlo simulations, Proc. International Conference on Communication (ICC), 2009

Abstract: Statistical detectors that are based on Markov chain Monte Carlo (MCMC) simulators have emerged as promising low-complexity solutions to both multiple-input multiple-output (MIMO) and code division multiple access (CDMA) communication systems. While these types of detectors achieve unprecedented near capacity performance, i.e., when operated in low signal-to-noise ratio (SNR) regime, they exhibit a serious problem at medium to high SNR regimes, referred to as the “stalling” problem. In this paper, we investigate the sources of this degradation and propose a new search strategy called constrained MCMC to remedy the issue of stalling.

[3] Ronghui Peng, Rong-Rong Chen and Behrouz Farhang-Boroujeny, Low Complexity Markov Chain Monte Carlo Detector for Channels with Intersymbol Interference, Proc. International Conference on Communication (ICC), 2009

Abstract: In this paper, we propose a novel low complexity soft-in soft-out (SISO) equalizer using the Markov chain Monte Carlo (MCMC) technique. Direct application of MCMC to SISO equalization (reported in a previous work) results in a sequential processing algorithm that leads to a long processing delay in the communication link. Using the tool of factor graph, we propose a novel parallel processing algorithm that reduces the processing delay by orders of magnitude. Numerical results show that, both the sequential and parallel processing SISO equalizers perform similarly well and achieve a performance that is only slightly worse than the optimum SISO equalizer. The optimum SISO equalizer, on the other hand, has a complexity that grows exponentially with the size of the memory of the channel, while the complexity of the proposed SISO equalizers grows linearly.

[4] Rong-Rong Chen, Ronghui Peng, and Behrouz Farhang-Boroujeny, Markov Chain Monte Carlo: Applications to MIMO detection and channel equalization, Proc. Information theory and applications workshop (ITA), 2009. (Invited paper), (Slides) 

Abstract: In this paper, we present an overview of recent work on the applications of Markov Chain Monte Carlo (MCMC) techniques to both multiple-input and multiple-output (MIMO) detection and channel equalization. In the setting of MIMO detection, we have shown that, even for very large antenna systems with high spectral efficiencies of 24 bits/channel use (8 transmit and 8 receive antennas with 64 QAM modulation), the MCMC MIMO detector can bring us within 2 dB of the channel capacity with a greatly reduced complexity compared to several versions of sphere decoding based detectors. For frequency selective channels, we demonstrate that MCMC-based equalizers yield excellent performance even for severe inter-symbol-interference (lSI) channels. The MCMC equalizer achieves significant performance gain over minimum mean square error (MMSE) linear equalizer and performs closely to the optimal maximum a posteriori probability (MAP) equalizer. We will also discuss new approaches that effectively alleviate the well-known high SNR problems in existing MCMC detectors.

[6] Ronghui Peng and Rong-Rong Chen, Design of Nonbinary Quasi-Cyclic LDPC Cycle Codes, Proc. IEEE Information Theory Workshop (ITW), Sep. 2007.

Abstract: In this paper, we study the design of nonbinary low-density parity-check (LDPC) cycle codes over Galois field GF(q). First, we construct a special class of nonbinary LDPC cycle codes with low error floors. Our construction utilizes the cycle elimination algorithm to remove short cycles in the normal graph and to select nonzero elements in the parity-check matrix to reduce the number of low-weight codewords generated by short cycles. Furthermore, we show that simple modifications of such codes are parallel sparse encodable (PSE). The PSE code, consisting of a quasi-cyclic (QC) LDPC cycle code and a simple tree code, has the attractive feature that it is not only linearly encodable, but also allows parallel encoding which can reduce the encoding time significantly. We provide a systematic comparison between nonbinary coded systems and binary coded systems. For the MIMO channel considered, our results show that the proposed nonbinary system employing the PSE code outperforms not only the binary LDPC code specified in the 802.16e standard, but also the optimized binary LDPC code obtained using the EXIT chart methods.

[7] Ronghui Peng and Rong-Rong Chen, Application of nonbinary LDPC codes for communication over fading channels using higher order modulations, Proc. IEEE Global Communication Conference (Globecom), 2006. (Slides)

Abstract: In this paper, we investigate the application of nonbinary low density parity check (LDPC) codes over Galois field GF(q) for both single-input single-output (SISO) and multiple-input multiple-output (MIMO) fading channels using higher order modulations. As opposed to the widely studied binary systems that employ joint detection and channel decoding, we propose a nonbinary system where optimal signal detection is performed only once followed by channel decoding. To reduce the complexity of proposed system, we first develop a low complexity LDPC decoding algorithm over GF(q) in the logarithmic domain. We then provide a quasi-cyclic construction of nonbinary LDPC codes which not only allows linear-time encoding, but also gives comparable performance to the best known progressive edge growth (PEG) codes. Our results show that the proposed system that employs regular nonbinary LDPC codes outperforms systems using the best optimized binary irregular LDPC codes in both performance and complexity.

[8] Ronghui Peng and Rong-Rong Chen, Design of nonbinary LDPC Codes over GF(q) for multipleantenna transmission, Proc. IEEE Military Communications Conference (Milcom), Oct. 23-25, Washington DC., 2006. (Slides)

Abstract: In this paper, we investigate the application of nonbinary low density parity check (LDPC) codes over Galois field GF(q) for multiple-input multiple-output (MIMO) fading channels. Depending on the size of the Galois field GF(q), we study both iterative systems which employ joint MIMO detection and channel decoding, and non-iterative systems which employ separate MIMO detection and channel decoding. Based on the concept of coset LDPC code and coset MIMO detector, we develop extrinsic information transfer chart (EXIT) approaches for the design of nonbinary LDPC codes for MIMO channels. Simulation results show that the proposed systems employing the designed nonbinary LDPC codes achieve a superior performance than that of the best optimized binary LDPC codes at a reduced complexity.

Joint channel coding and detection for efficient communication over fading channels. (Proposal sides, Defense slides)

Selected Presentations

Application of MCMC for MIMO and ISI channels  

Advanced Receiver algorithm for MIMO system

LTE Physical layer overview

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