Adaptive-Array Algorithm for Interference Suppression Prior to Acquisition of Direct-Sequence Signal

• Published in: IEEE transactions on wireless communications Vol. 7; no. 9; pp. 3341 - 3346
• Main Authors: Torrieri, D., Bakhru, K.
• Format: Journal Article
• Language: English
• Published: Piscataway, NJ IEEE 01.09.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Acquisitions; Adaptive arrays; Algorithms; Antennas; Applied sciences; Array signal processing; code acquisition; Detection, estimation, filtering, equalization, prediction; direct sequence; Directive antennas; Electronic mail; Exact sciences and technology; Information, signal and communications theory; Interference; Interference cancellation; Interference suppression; Marketing; Military computing; Miscellaneous; Phased arrays; Pilots; Radiocommunications; Receiving antennas; Rendering; Signal and communications theory; Signal processing; Signal to noise ratio; Signal, noise; Spreading; Telecommunications; Telecommunications and information theory; Wireless communication; Direction-of-arrival estimation; Parameter estimation; Adaptive algorithm; Noise reduction; Adaptive arrays; Signal estimation; Adaptive antenna arrays; Interference suppression; Acquisition process; Code acquisition; Signal processing; Direct sequence; Signal detection
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2008.070398

Strong directional interference can prevent code acquisition in a direct-sequence system, thereby rendering the system inoperable. This paper presents a computationally simple adaptive-array algorithm that cancels directional interference prior to code acquisition when the direction of arrival of the desired signal is unknown, no pilot symbols are available, and long spreading sequences must be accommodated. The preacquisition algorithm is shown to dramatically reduce the interference level relative to that of a desired direct-sequence signal before code acquisition has been achieved. As a result, the code acquisition process is greatly facilitated.