An adaptive multiuser detector based on radial basis function network and linear adaptive filter for DS/CDMA communications

• Published in: Electronics & communications in Japan. Part 3, Fundamental electronic science Vol. 86; no. 10; pp. 19 - 35
• Main Authors: Miyake, Motoharu, Oishi, Kunio, Sakaniwa, Kohichi
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 01.10.2003
• Subjects: co-channel interference; direct-spread code division multiple access; multiuser detector; RBF detector; signal-to-interference ratio
• ISSN: 1042-0967; 1520-6440
• DOI: 10.1002/ecjc.1154

In this paper, we propose a radial basis function–linear adaptive filter (RBF‐LAF) detector that uses a radial basis function (RBF) network with an MMSE (minimum mean squared error) detector based on a linear adaptive filter (LAF) to suppress co‐channel interference in DS‐CDMA communications. The objective of the proposed RBF‐LAF detector is to achieve an excellent bit error rate while limiting the computational complexity by calculating the received signal power or the signal‐to‐interference ratio (SIR) of each user and assigning an RBF detector to users receiving strong co‐channel interference and an MMSE‐LAF detector to users experiencing little interference. By appropriately assigning the users, an excellent bit error rate can be obtained with a relatively low computational complexity compared to conventional RBF detectors. And by using an adaptive algorithm, changes in the communication environment can be handled. Finally, the effectiveness of the proposed method is demonstrated by comparing the proposed RBF‐LAF detector and the conventional detectors in terms of the bit error rate and the computational complexity in numerical examples. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 86(10): 19–35, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1154