BOC/MBOC Multicorrelator Receiver with Least-Squares Multipath Mitigation Technique

Fernando D. Nunes, Fernando M.G. Sousa, Jose M.N. Leitao

Abstract:	The conventional techniques used for multipath mitigation in GNSS receivers, such as the Narrow Correlator or the High Resolution Correlator, present serious limitations in complex multipath environments characterized by several reflected rays. An alternative is to resort to algorithms, such as the Multipath Estimating Delay Lock Loop (MEDLL) or the Multipath Mitigation Technique (MMT), that estimate the number, magnitude, delay and phase of the line-of-sight and the reflected signals. However, the weakness of these techniques is the steep increase of its computational burden with the number of reflected rays. Herein, we propose the application of the Levenberg- Marquardt (LM) algorithm to the code synchronization in multipath scenarios characterized by a large number of reflectors. The computational effort is kept at a reasonable level by assuming that the channel consists of a direct ray and a few reflectors despite the actual number of reflectors existing in the physical channel (in the paper we have considered 3 reflected rays for the LM algorithm). Besides, the proposed technique is highly parallelizable which permits to accelerate the speed of processing. Simulations show a good performance of the proposed algorithm in environments with a large number of reflectors. This includes situations of mismatch between the number of reflectors assumed by the algorithm and the true number of reflected signals.
Published in:	Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008) September 16 - 19, 2008 Savannah International Convention Center Savannah, GA
Pages:	652 - 662
Cite this article:	Nunes, Fernando D., Sousa, Fernando M.G., Leitao, Jose M.N., "BOC/MBOC Multicorrelator Receiver with Least-Squares Multipath Mitigation Technique," Proceedings of the 21st International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2008), Savannah, GA, September 2008, pp. 652-662.
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