Blind adaptive multiuser detector for nonlinearly modulated satellite mobile CDMA systems

Shao, Shixiang; Yang, Longxiang; Kwak, Kyungsup

doi:10.1007/s11767-004-0142-y

Cited by 1 publication

(1 citation statement)

References 7 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It has been studied that when there is no line of sight component the envelop follows the Rayleigh distribution, and when a line of sight component exists the envelope follows the Rice distribution [18][19][20] . Here we employ a flat Rice fading channel with AWGN noise because a satellite channel can be taken as a flat fading channel when the bandwidth of the carrier is no more than 10 MHz [21] . Rice channel is generated by superposing a line of sight component on a Rayleigh model and we get the envelope of Rice channel [18] : σ The ratio of specular to scatter energy defines the so-called Rice K-factor, which is given by…”

Section: The Satellite Communication Channelmentioning

confidence: 99%

CAPS satellite spread spectrum communication blind multi-user detecting system based on chaotic sequences

Lei

Shi

2009

Sci. China Ser. G-Phys. Mech. Astron.

View full text Add to dashboard Cite

Multiple Path Interference (MPI) and Multiple Access Interference (MAI) are important factors that affect the performance of Chinese Area Positioning System (CAPS). These problems can be solved by using spreading sequences with ideal properties and multi-user detectors. Chaotic sequences based on Chebyshev map are studied and the satellite communication system model is set up to investigate the application of chaotic sequences for CAPS in this paper. Simulation results show that chaotic sequences have desirable correlation properties and it is easy to generate a large number of chaotic sequences with good security. It has great practical value to apply chaotic sequences to CAPS together with multi-user detecting technology and the system performance can be improved greatly.Multiple Path Interference (MPI), Multiple Access Interference (MAI), Chebyshev map, chaotic sequences, blind multi-user detection Chinese Area Positioning System (CAPS) is a satellite based positioning and communication system, which is expected to have a promising future with the advantages of strong interference immunity, good security and wide coverage [1][2][3][4][5] . Concerning its communication, Multiple Path Interference (MPI) and Multiple Access Interference (MAI) are the main issues in CAPS system because of the high capacity and low SNR (Signal to Noise Ratio) [6,7] . The impact of MPI and MAI can be mitigated by employing good spreading sequences and using a multi-user detector at the receiving end [8,9] . M sequences, Gold sequences, etc., have been traditionally used as spreading codes in spread spectrum communication systems. These sequences are generated by linear shift registers, which are small in number and low in complexity. Transmission security of traditional spread spectrum communication has been challenged by the rapid development of deciphering technique [10,11] . Chaos is a random-like and nonlinear process which has been extensively used in communication systems since the last decades. Due to the high initial values sensitivity, a large number of chaotic sequences with good properties and security can be generated easily, which has opened up a new way for spread spectrum communication [12,13] . Chaotic sequences have become applicable since the synchronization of chaos was solved and have drawn increasing attention, therefore becoming a research focus [14] .Successful applications of chaotic sequences in the satellite communication system have seldom been reported although much research has been done. Logistic map, Tent map and Chebyshev map are the most commonly used [15][16][17] and we study the properties of chaotic sequences based on Chebyshev map. Satellite spread spectrum communication systems with receivers using a conversational matched filter and a blind multi-user detector based on Least Mean Squares (LMS) algorithm

show abstract

Section: The Satellite Communication Channelmentioning

confidence: 99%