Multi-objective approach in GNSS code discriminator design

• Published in: IEEE transactions on aerospace and electronic systems Vol. 44; no. 2; pp. 481 - 492
• Main Author: Juang, Jyh-Ching
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2008; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Binary phase shift keying; Correlators; Design engineering; Discriminators; Global navigation satellite system; Global Positioning System; GNSS; Linear programming; Optical signal processing; Phase shift keying; Receivers; Rendering; Satellite navigation systems; Spread spectrum; Spread spectrum communication; Spreads; Studies; Tracking; Tracking loops; Vectors
• ISSN: 0018-9251; 1557-9603
• DOI: 10.1109/TAES.2008.4560201

In spread spectrum ranging system receivers such as the Global Navigation Satellite System (GNSS) receivers, a discriminator is used in the code tracking loop to provide an error signal for the tracking of incoming signals. Typically, the discriminator manipulates several correlator outputs to form the correction signal. A multi-objective approach is adopted here to design the coefficients associated with a multi-correlator-based discriminator to lead to a better performance tradeoff in large tracking range, acceptable multipath-induced bias, high sensitivity, free of ambiguity, and small variance. It is shown that the multiple-objective problem can be tackled via a quadratic/linear programming method, rendering the optimal coefficient vector for the implementation of the discriminator. In addition, as the discriminator design is often subject to conflicting requirements, it is shown that the proposed design approach is capable of establishing bounds on achievable performance. Examples with respect to BPSK (binary phase-shift keying) NRZ (nonreturn-to-zero), and BOC (binary-offset carrier) signals are given to illustrate the design approach.