Research Areas

Reed-Solomon (RS) codes have a great many applications, such as in magnetic recording systems, etc., right after their invention because of their good property to protect communication systems from noise bursts. Low-density parity-check (LDPC) codes have gained a lot of research in these years due to their powerful random error-correction capability. Research has shown a potential better performance of replacing current hard-decision RS coded magnetic recording systems with LDPC codes. However, Koetter and Vardy (2000) proposed a soft-decision algorithm based on Guruswami and Sudan's breakthrough research on RS decoding algorithm (1997), which largely improves the RS decoding capability over additive Gaussian white noise channel. All these lead to my research as follows ...

Reed-Solomon Codes and Their Decoding Algorithms

Traditional RS decoding algorithms

	Berlekamp-Massay algorithm, Welch-Berlekamp algorithm
	Generalized-Minimum-Distance (GMD) algorithm, Chase algorithm, Combined Chase-GMD algorithm, Ordered statistic decoding algorithm, etc.

Interpolation-based RS decoding algorithms

	Guruswami-Sudan algorithm
	Koetter-Vardy algorithm *(Soft-decision RS decoding algorithm)*
	Re-encoding algorithm

Algorithms proposed in our research

	Suboptimal multiplicity matrix computation algorithm
	Soft Chase RS decoding algorithm
	Combined soft Chase and re-encoding algorithm
	Forward recursive RS decoding algorithms

Application and Implementation of Soft-decision RS Decoding Algorithms on Magnetic Recording Systems

Magnetic recording systems requirements:

Higher rate code, higher decoding speed, lower complexity, strong errors burst correction capability !

Performance evaluation of soft-decision RS decoding algorithms

Retry mode scheme to combining current hard-decision RS decoding oriented system with soft-decision RS decoding

Reduced-complexity implementation of soft-decision RS decoding

Combined soft Chase and re-encoding algorithm

Combined forward recursive and re-encoding algorithm

Performance evaluation of channels with erasures (error bursts)

Erasure channel model

Effect of noise overestimation (also called SNR mismatch) on BCJR detector as well as soft-decision RS decoder

Erasure detection techniques and system architectures utilizing the noise overestimation effect

Performance evaluation of RS codes concatenated with other codes

Channel Detector in Magnetic Recording Systems

	*PRML, SOVA, BCJR*
	*Noise overestimation effect on channel detector*
	*Interaction between channel detector and error-correction code (ECC) decoder such as RS decoder*

LDPC Codes and Their Application on Magnetic Recording Systems

	*Code design such as array LDPC codes, RS-based LDPC codes*
	*Performance evaluation*
	*Noise overestimation effect for LDPC decoder*

Nested Codes and Their Application on Magnetic Recording Systems

Performance evaluation of nested RS codes, nested LDPC codes for random errors and erasure bursts

Error location information sharing scheme for nested codes

Iterative Soft-Decision RS Decoding Algorithms (In progress ...)

Sparse or partial sparse parity check matrix of RS codes for message passing decoding

Generalized belief propagation algorithm

Reliability-based decoding algorithm

Performance evaluation over magnetic recording channels

ECC Codes on Wireless Communication Systems

ECC codes over Rayleigh fading channels (Presented one paper on this topic at Globecom2003 conference, and won $1000 IEEE student travel grant)

Automatic-repeat-request (ARQ) for packet-oriented wireless systems (Submitted one paper on this topic at Globecom2004 conference)

Rate-compatible coding scheme

Space-time coding scheme (One paper in preparation)

For detailed research results, please see in my publications!

Home | OU | Department of Electrical and Computer Engineering| OU Libraries

This site was last updated 04/16/04

OU Home | Disclaimer | Copyright | Equal Opportunity | OU Web Policy