Title :
Iterative PDF estimation and turbo-decoding scheme for DS-CDMA systems with non-Gaussian global noise
Author :
Yuan Li ; Li, Kwok H.
Author_Institution :
Centre for Wireless Commun., Nat. Univ. of Singapore, Singapore
Abstract :
In some multiuser direct-sequence code-division multiple-access (DS-CDMA) systems, the commonly used Gaussian approximation (GA) is inaccurate to describe the probability density function (PDF) of the global noise, which is the sum of the multiple-access interference (MAI) and channel noise. This inaccuracy causes the performance degradation of turbo codes as compared to decoders based on the true PDF. Therefore, an iterative PDF estimation and turbo-decoding scheme is proposed, where the kernel-based method is used to estimate the PDF from the global-noise samples refined from the received signals, and the information is iteratively exchanged between the PDF estimator and the turbo decoder. This scheme achieves performance comparable to decoders based on true PDF after several iterations
Keywords :
adaptive decoding; approximation theory; code division multiple access; multiuser channels; noise; parameter estimation; probability; radiofrequency interference; spread spectrum communication; turbo codes; DS-CDMA systems; Gaussian approximation; PDF; channel noise; direct-sequence code-division multiple-access; iterative PDF estimation; kernel-based method; multiple-access interference; multiuser systems; nonGaussian global noise; probability density function; turbo codes; turbo decoder; turbo-decoding; AWGN; Additive white noise; Gaussian approximation; Gaussian noise; Iterative decoding; Multiaccess communication; Multiple access interference; Probability density function; Turbo codes; Wideband;
Conference_Titel :
Global Telecommunications Conference, 2001. GLOBECOM '01. IEEE
Conference_Location :
San Antonio, TX
Print_ISBN :
0-7803-7206-9
DOI :
10.1109/GLOCOM.2001.966289
