Lin Xuehong

Bio: Lin Xuehong is an academic researcher from Beijing University of Posts and Telecommunications. The author has contributed to research in topics: Sequential decoding & List decoding. The author has an hindex of 3, co-authored 4 publications receiving 12 citations.

Improvement of Shuffled Iterative Decoding

Abstract: An improved version of shuffled belief propagation of iterative decoding of LDPC codes is proposed. The proposed scheme can speed up the convergence of iterative decoding. Simulation results verified our conclusions.

LDPC codes for unequal error protection

Abstract: This paper proposed LDPC codes with lower triangular parity check and the modified decoding algorithm, which can achieve unequal error protection for transmission bitstream with different level of protection. It is well suitable for transmitting the important sequence in front of codeword, such as wavelet-based image codecs.

Designing of Fountain Codes in Cooperative Relay Systems

Abstract: As the degree distribution of fountain codes plays a key role in affecting their performance, this paper presents a designing method of degree distribution based on the characteristics of relay systems, and optimizes the fountain codes in 3GPP. Simulation results show that the designed fountain codes have a good decoding performance in relay systems, compared to the fountain codes in 3GPP. In the multicast system, in order to improve the decoding performance for all users, we can choose the optimization parameters according to the circumstances of relay system.

MAP decoding of variable length codes based on a new 'bit-level' trellis

Abstract: Soft information associated with each bit in the output of variable length codes (VLC) can be used to improve the performance of VLC decoding, especially in a joint source-channel decoding structure. But the main problem of the decoding in bit level is the huge number of states, which is linear with the value of the trellis bit step parameter. In this paper, according to tree presentation of VLC, a new 'bit-level' trellis is presented, which states are less than the number of nodes in the VLC tree. Moreover, it allows the application of the maximum a posteriori (MAP) algorithm, and is more convenient to construct than previous represented we have found in literatures.

Enhancement of unequal error protection properties of LDPC codes

Abstract: It has been widely recognized in the literature that irregular low-density parity-check (LDPC) codes exhibit naturally an unequal error protection (UEP) behavior. In this paper, we propose a general method to emphasize and control the UEP properties of LDPC codes. The method is based on a hierarchical optimization of the bit node irregularity profile for each sensitivity class within the codeword by maximizing the average bit node degree while guaranteeing a minimum degree as high as possible. We show that this optimization strategy is efficient, since the codes that we optimize show better UEP capabilities than the codes optimized for the additive white Gaussian noise channel.

Variable-to-check residual belief propagation for LDPC codes

Abstract: Variable-to-check residual belief propagation for LDPC decoding for faster convergence, better error performance and lower complexity is proposed. It is similar to residual belief propagation (RBP) that was recently applied to LDPC decoding by Vila Casado et al. because it is also a dynamic scheduling belief propagation using residuals, but it is different because the residuals are computed from a variable-to-check message. Simulation shows that it outperforms with only a maximum of eight iterations by about 0.3 dB compared with RBP at an FER of 10−4.

Apparatus and method for transmitting data using fountain code in wireless communication system

Abstract: An apparatus and a method for transmitting data using a fountain code are provided. The method for transmitting data includes determining a degree distribution of a fountain code based on erasure rate information regarding at least one receiving end, performing fountain encoding according to the degree distribution, and transmitting symbols generated by the fountain encoding.

Degree reduction and degree-constrained combining for relaying a fountain code

Abstract: A method, an apparatus, and a computer program product for relaying a packet are provided. The apparatus receives at least one packet and reduces a degree of the at least one packet. The apparatus further processes the at least one packet based on the reduced degree, generates a combined packet by combining the at least one processed packet with at least one other processed packet based on the reduced degree and a weight of each of the processed packets, and transmits the combined packet.