An Optimized and Payload Achievable Multiplexing Design Technique for GNSS Signals

Jiayi Zhang, Zheng Yao, Junjie Ma, Mingquan Lu, Xin Zhang

Abstract:	Constant envelope multiplexing (CEM) techniques are used to combine multiple signals of Global Navigation Satellite Systems (GNSS), so that signals on adjacent frequencies can be transmitted through a common up-converter, power amplifier chain and antenna on satellite payload. Along with the increasing of number of signal components and bandwidth of components, more sophisticated CEM techniques are required, resulting in that the CEM signals are with more complex composition and of larger bandwidth. The transmitting channel on satellite, however, is of limited bandwidth. After passing these channel, some high frequency components of the wideband CEM signal get lost, which destroys the envelope constant property of signal, thus introduces distortion at high power amplifier (HPA). In order to maintain the envelope constancy and reduce distortion of signal in CEM design, this paper presents a methodology focusing on the envelope constant after the equivalent filter of transmitters. Problem formulation, algorithms and an application example are provided. Comparison is conducted with a traditional CEM solution. Results show that a derived scheme of the proposed CEM design method does reduce the divergence of the envelope after filtering, while achieving compatible performance in power efficiency. The proposed method allows navigation system designers to adjust CEM schemes according to hardware implementation of transmitters on payload, thus reducing the distortion caused by imperfection of payload.
Published in:	2018 IEEE/ION Position, Location and Navigation Symposium (PLANS) April 23 - 26, 2018 Hyatt Regency Hotel Monterey, CA
Pages:	1439 - 1444
Cite this article:	Zhang, Jiayi, Yao, Zheng, Ma, Junjie, Lu, Mingquan, Zhang, Xin, "An Optimized and Payload Achievable Multiplexing Design Technique for GNSS Signals," 2018 IEEE/ION Position, Location and Navigation Symposium (PLANS), Monterey, CA, April 2018, pp. 1439-1444. https://doi.org/10.1109/PLANS.2018.8373537
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