Software Listing of Author : "Yang Xiao"
- Alternative good LDPC codes for DVB-S2
- License: Freeware
- Price: 0.00


In our following paper, we find that the shortten codes of DVB-S2 have some problems,this program can provide a good DVB-S2 LDPC code without cascaded BCH codes. [1] Yang Xiao, Kiseon Kim, "Alternative good LDPC codes for DVB-S2", 9th International Conference on Signal Processing, 2008 (ICSP 2008), Beijing, 26-29 Oct. 2008, page(s): 1959-1962, ISBN: 978-1-4244-2178-7, INSPEC Accession Number: 10411270, Digital Object Identifier: 10.1109/ICOSP.2008.4697527, Current Version Published: 2008-12-08 The paper can be downloaded from Web site of IEEE Explore.
- Platform: Matlab, Scripts
- Girth 4 of Gallager codes
- License: Shareware
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The Program to test the girth 4 of Gallager LDPC codes Copyright (C) Yang XIAO, BJTU, July 26, 2007, E-Mail: yxiao@bjtu.edu.cn, The program analyzes the girth 4 for Gallager LDPC codes. The figures show the parity check matrix H and the girth test matrix O, respectively. Fig 1 can help us know the 1s' distribution of the parity check matrix H. Fig. 2 is the result of girth 4 for the given H. Theorem in Ref [1]: The H matrix has no gith4, if and only if the O matrix in Fig.2 has no entry value to be larger than 1. Ref: [1] Y. Xiao, M -H Lee, 'Low complexity MIMO-LDPC CDMA systems over multipath channels', IEICE Transactions on Communications, v E89-B, n 5, May, 2006, p 1713-1717 [2] J. Fan, Y. Xiao, 'A method of counting the number of cycles in LDPC codes', 8th International Conference on Signal Processing, ICSP 2006,Volume: 3, ISBN:...
- Platform: Matlab, Scripts
- Girth 4 test for LDPC codes
- License: Freeware
- Price: 0.00


Recently, we find some published programs for the construction of LDPC codes have not concerned the Girth test problem, which will not the implementation of LDPC Codec to have good decoding BER. Thus, we publish a simple program to provide a tool for the girth 4 test of LDPC codes. Input a parity check matrix H with the format of the example in the program, the program can determine whether it has girth 4.
- Platform: Matlab, Scripts
- Hurwitz-Schur Stability Test of 2-D Polynomials
- License: Shareware
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Hurwitz-Schur Stability Test of 2-D Polynomials Copyright (C) Yang XIAO, Beijing Jiaotong University, Aug.8, 2007, E-Mail: yxiao@bjtu.edu.cn. The stability of 2-D continuous-discrete systems and time-delay systems can be determined by the Hurwitz-Schur Stability of characteristic polynomials of the systems [1-3]. The characteristic polynomials can be expressed as a 2-D Polynomial in s-z domain: B(z1,z2)=[1 z^(-1) z^(-2)]*B*[1 s s^2]'. This program derived from the main results of Ref. [1-3], and it can test the Hurwitz-Schur Stability of 2-D Polynomials. Ref: [1] Y. Xiao; Stability test for 2-D continuous-discrete systems, Proceedings of the 40th IEEE Conference on Decision and Control, 2001. Volume 4,4-7 Dec. 2001 Page(s):3649 - 3654 vol.4 [2] Y. Xiao Yang, 2-D stability test for time-delay systems, Proceedings of 2001...
- Platform: Matlab, Scripts
- inverse 2-D Laplace transform
- License: Shareware
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You can follow the examples given in the codes, to construct your 2-D fuction in 2-D Laplace transform domain, insert it into the place of our examples, then you can get the inverse 2-D Laplace transform of your function.
- Platform: Matlab, Scripts
- inverse 2-D Laplace-z transform
- License: Shareware
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The program can get spatial-time response of 2-D Continuous-Discrete systems by taking inverse 2-D Laplace-z transform [1]. The detailed algorithm is provided in Ref. [1]. Copyright (C) Yang XIAO, BJTU, July 28, 2007, E-Mail: yxiao@bjtu.edu.cn. Based on recent results for 2-D continuous-discrete systems, Ref. [1] develops 2-D Laplace-z transform, which can be used to analyze 2-D continuous-discrete signals and system in Laplace-z hybrid domain. Current 1-D Laplace transformation and z transform can be combined into the new 2-D s-z transform. However, 2-D s-z transformation is not a simple extension of 1-D transform, in 2-D case, we need consider the 2-D boundary conditions which don't occur in 1-D case. The hybrid 2-D definitions and theorems are given in Ref. [1]. This program is derived from the numerical inverse 2-D Laplace-z...
- Platform: Matlab, Scripts
- inverse 2-D z transform for 2-D recursive discrete system
- License: Shareware
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The program can get the 2-D impulse response of a 2-D recursive discrete system in 2-D digital domain. For a 2-D recursive discrete system, the inverse 2-D z transform can be implemented by a 2-D IIR filter [1-3]. Copyright (C) Yang XIAO, Beijing Jiaotong University, Aug.1, 2007, E-Mail: yxiao@bjtu.edu.cn. Resort to the theorems in Ref. [1-3], we can get a stable 2-D recursive discrete system, with stable transfer function H(z1,z2)=A(z1,z2)/B(z1,z2) in 2-D z-domain. Since the transfer function is stable, the 2-D impulse response h(n1,n2) of the system equals the solution of a 2-D IIR filter to process a unit impulse in 2-D digital domain [3]. Then this program can get the 2-D impulse response of a given 2-D recursive discrete system in 2-D digital domain if the system is stable. The stability test for the two examples is provided in...
- Platform: Matlab, Scripts
- Parity Check Matrices of DVBS2 codes
- License: Freeware
- Price: 0.00


Copyright (C2010-2013) Yang XIAO, BJTU, April 16, 2010, E-Mail: yxiao@bjtu.edu.cn. This program can produce the Parity Check Matrices of DVBS2 codes, while Ref. [1] remindes you that these codes are not good as the LDPC codes IEEE802.16e for continuous bits' errors. Refenrences: [1] X. Huang, Y. Xiao, J. Fan and K. Kim, Girth 4 and low minimum weights' problems of LDPC codes in DVB-S2 and solutions, Proceedings of the 5th International Conference on Wireless communications, networking and mobile computing table of contents Beijing, China, Pages: 601-604, 2009, ISBN:978-1-4244-3692-7 [2] Xiao Y., Kim K, "Alternative good LDPC codes for DVB-S2", 9th International Conference on Signal Processing, 2008. ICSP 2008. Beijing, 26-29 Oct. 2008, Page(s): 1959-1962 [3] DVB-S2 standard draft ETSI EN 302 307 V1. 1. 1[S]. 2004, 06.
- Platform: Matlab, Scripts
- Shortten DVB-S2 LDPC 64800 code into 8100
- License: Shareware
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The program can produce the parity check matrix of DVB-S2 LDPC with the size 8100*4050, and 1/2 code rate. Copyright (C) Yang XIAO, Beijing Jiaotong University, June 22, 2010, E-Mail: yxiao@bjtu.edu.cn. Current Version Published: 2010-6-22 In our following papers [1,2], we find that the shortten codes of DVB-S2 LDPC have some problems. This program can provide a shortten code from DVB-S2 LDPC. This program is to shorten DVB-S2 LDPC 1/2 rate 64800 code into 1/2 rate 8100 code without Girth 4 by using the parity check matrix program as follows: http://www.mathworks.com/matlabcentral/fileexchange/27265-parity-check-matrices-of-dvbs2-codes References: [1] Yang Xiao, Kiseon Kim, "Alternative good LDPC codes for DVB-S2", 9th International Conference on Signal Processing, 2008 (ICSP 2008), Beijing, 26-29 Oct. 2008, page(s): 1959-1962. [2]...
- Platform: Matlab, Scripts
- simulate fast Tanner LDPC codec with quasi-circular generator matrices
- License: Freeware
- Price: 0.00


The program can simulate fast Tanner LDPC codec with quasi-circular generator matrices, and 1/2 code rate. Copyright (C2010-2015) Yang XIAO, Beijing Jiaotong University, Nov.3, 2010, E-Mail: yxiao@bjtu.edu.cn. Current Version Published: 2010-11-5 In my following books, I derived the algorithm of constructing quasi-circular generator matrices from Tanner codes. [1] Yang Xiao, Turbo and LDPC Codecs and their Applications, Press of Posts and Telecommunications, Beijing, 2010. [2] Yang Xiao, MIMO Multiple Antenna Wireless Communication Systems, Press of Posts and Telecommunications, Beijing, 2009. You can obtain different size of Tanner codes by adjusting parameter b, which should be a prime number [1,2]. Existing Tanner codes can not derive quasi-circular generator matrices, we revise the Tanner codes' parity check matrices [1,2]
- Platform: Matlab, Scripts
- Simulating 2*2 MIMO-LDPC Base-Band Systems
- License: Shareware
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Simulating 2*2 MIMO-LDPC Base-Band Systems Copyright (C2010-2015) Yang XIAO, Beijing Jiaotong University, Aug.10, 2010, E-Mail: yxiao@bjtu.edu.cn. This program can simulate 2*2 MIMO-LDPC base-band systems. The MIMO system's design can refer my following book. [1] Yang Xiao, MIMO Multiple Antenna Wireless Communication Systems, Press of Posts and Telecommunications, Beijing, 2009. Different from the MIMO scheme of IEEE 802.16e, our MIMO-LDPC system has no space-time coding, while it achieved good BER performance.
- Platform: Matlab, Scripts
- Stability Test of 2-D Face of an Interval Matrix
- License: Shareware
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The program can test the stability of 2-D face of an interval matrix. Copyright (C) Yang XIAO, Beijing Jiaotong University, Aug.2, 2007, E-Mail: yxiao@bjtu.edu.cn. By relying on a two-dimensional (2-D) face test, Ref [1,2] obtained a necessary and sufficient condition for the robust Hurwitz and Schur stability of interval matrices. Ref [1,2] revealed that it is impossible that there are some isolated unstable points in the parameter space of the matrix family, so the stability of exposed 2-D faces of an interval matrix guarantees stability of the matrix family. This program provides the examples to demonstrate the applicability of the robust stability test of interval matrices in Ref [1, 2]. Remarks: (1) The 2-D face of an interval matrix is Hurwitz stable, if and only if the maximum real part of the eigenvalues of the 2-D face of the...
- Platform: Matlab, Scripts
- Stability Test of AQM Network
- License: Shareware
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The program can determine the stability of AQM networks [1-3]. The detailed algorithm is provided in Ref. [1]. Copyright (C) Yang XIAO, Beijing Jiaotong Univ., Oct. 26, 2007 Contact Add: Prof. Yang XIAO Institute of Information Science Beijing Jiaotong University Beijing 100044, China E-Mail: yxiao@bjtu.edu.cn. Recent research reveals that the fluid-based model can describe the dynamic behavior for bottleneck networks [1-3]. The stability of the fluid-based model can reflect whether there exists a congestion of the network. We develop a linearization processing [1] for fluid-based model [2,3] at equilibrium points for the stability analysis of the networks with Active Queue Management (AQM). The bottleneck networks are described by uncertain linear time-delay systems [1], then 2-D (two-dimensional) Laplace-z transform has been...
- Platform: Matlab, Scripts
- The parity check matrix of IEEE 802.16e LDPC with the size 2256*4512
- License: Shareware
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In my following book, I derived the algorithm of constructing the parity check matrices of IEEE 802.16e LDPC. [1] Y. Xiao, Turbo and LDPC Codecs and their Applications, Press of Posts and Telecommunications, Beijing, 2010. This program provides the LDPC code with the size 4512*2256, and 1/2 code. When you get H, you can use well known LDPC simulator of 1/2 rate to get the good BER curve as we provided
- Platform: Matlab, Scripts
- The problems of LDPC codes in CCSDS 13-P-1.1
- License: Shareware
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We found that the generator matrix in Fig.6-2 to be wrong, Bi,j's are not circulant. You can not derive circulant Bi,j's from the parity check matrix in Fig.6-1. There are two vital problems in the LDPC codes of CCSDS 131.0-P-1.1: (1) the parity check matrix in Fig.6-1 is not full rank; (2) the generator matrix in Fig.6-2 is wrong, which are not circulant. To check our comments for the CCSDS 131.0-P-1.1 codes, you only construct the generator matrix in Fig.6-2, then multiply the transpose of the the parity check matrix in GF(2) provided by our program. You will find that the product in GF(2) is not zero!
- Platform: Matlab, Scripts
