Semi-random LDPC codes for CDMA communication over non-linear band-limited satellite channels

2006 ◽  
Vol 24 (4) ◽  
pp. 303-317 ◽  
Author(s):  
Mohamed Adnan Landolsi
Keyword(s):  
Ldpc Codes ◽  
Non Linear ◽  
Satellite Channels ◽  
Linear Band ◽  
Band Limited

scholarly journals Combination of High-Order Modulation and Non-Binary LDPC Codes over GF(7) for Non-Linear Satellite Channels

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1396 ◽  
Author(s):  
Yanyan Liu ◽  
Weigang Chen ◽  
Anguo Wang ◽  
Changcai Han
Keyword(s):  
Communication System ◽  
Satellite Communication ◽  
Additive White Gaussian Noise ◽  
Ldpc Codes ◽  
High Order ◽  
Modulation Scheme ◽  
Satellite Communication System ◽  
Awgn Channel ◽  
Non Linear ◽  
Satellite Channels

High-order modulations are necessary to improve the bandwidth efficiency of the satellite communication system. However, the non-linear characteristic of satellite channels limits the application of high-order modulations. In this paper, we propose a new 7-point constellation which is expected to be effectively applied to the satellite communication system, and combine it with non-binary low-density parity-check (NB-LDPC) codes over Galois field GF(7) to guarantee the reliability of the data transmission. The exact expression for the average symbol error probability (SEP) of 7-order quadrature amplitude modulation (7-QAM) over the Additive White Gaussian Noise (AWGN) channel is derived, and the non-linear distortion over satellite channels is also analyzed. Simulation results reveal that, compared with the traditional 8-order phase-shift keying (8-PSK), the 7-QAM method can achieve about 3 dB gain over the AWGN channel without channel coding at symbol error rate (SER) of 10 - 6 . Moreover, the proposed combined coded modulation scheme also has better SER performance than the NB-LDPC coded 8-PSK modulation scheme over the non-linear satellite channel.

The Performance of 8PSK Modulation with Continuous Phase in the Satellite Channel

2012 ◽  
Vol 198-199 ◽  
pp. 1726-1732
Author(s):  
Ying Jue Ju ◽  
Jiang Zhu ◽  
Yong Ming Fu ◽  
En Gang Wang ◽  
Wei Qiang Yuan ◽  
...  
Keyword(s):  
Continuous Phase ◽  
Bandwidth Efficiency ◽  
Theory Analysis ◽  
Non Linear ◽  
Band Limited

Satellite channel is a typical band-limited and non-linear channel, and 8PSK signal with continuous phase (CP8PSK) is proposed to provide better SER performance in the channel. CP8PSK has higher bandwidth efficiency than GMSK and SOQPSK. Although CP8PSK’s SER performance is 1.5dB worse than traditional 8PSK signal in the Gauss channel, it has better performance in nonlinear satellite channel. With theory analysis and simulation, this paper compares the characteristics of 8PSK and CP8PSK working in the nonlinear satellite channel, especially considering the situation when the amplifier working in the nonlinear area.

scholarly journals ON-SKY DEMONSTRATION OF A LINEAR BAND-LIMITED MASK WITH APPLICATION TO VISUAL BINARY STARS

2010 ◽  
Vol 715 (2) ◽  
pp. 1533-1538 ◽  
Author(s):  
J. Crepp ◽  
E. Serabyn ◽  
J. Carson ◽  
J. Ge ◽  
I. Kravchenko
Keyword(s):  
Binary Stars ◽  
Visual Binary ◽  
Linear Band ◽  
Band Limited ◽  
Visual Binary Stars
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