Time division multiplexing continuous phase direct carrier modulation and demodulation method

Abstract

The invention discloses a time division multiplexing continuous phase direct carrier modulation and demodulation method. The modulation of the method is based on time division structured continuous phase direct carrier modulation. Data bits are modulated at the first half cycle of a basic carrier; ranging codes are modulated at the second half cycle; two kinds of information time divisions share one carrier cycle; data demodulation and ranging comprise steps of peeling off carriers; tracking and compensating carrier dynamic states, comprising frequency offsets imported by RF carriers before down-conversion; demodulating additional phases; carrying out binary data demodulation; tracking pseudo-random codes through related integration and low-pass filtering, thus realizing compensation of ranging and signal dynamic states. According to the method provided by the invention, the direct carrier continuous phase modulation concept is applied in designing ranging and communication signal waveform sets; secure and reliable navigation and information transmission in a dynamic application environment can be realized; moreover, the frequency spectrum is compressed; the multipath and radio frequency interferences are prevented; and signal tracking and demodulation are easy to be realized.

Description

technical field [0001] The invention belongs to the technical field of ranging and communication of a navigation system, and in particular relates to a time-division multiplexing continuous phase direct carrier modulation and demodulation method. Background technique [0002] With the deployment of various wireless facilities and the use of equipment, the wireless spectrum in the air is becoming more and more crowded, wireless resources are becoming more and more scarce, and the harm to the system is also greater. At the same time, with the improvement of informatization, various wireless transmission devices face the challenges of high speed and high spectral efficiency. [0003] From the perspective of the simplest binary modulation of a digital communication system, two different waveforms of limited duration can be used to represent "0" and "1" information bits respectively, and generally encoded in advance to ensure that the two information bits, etc. probability to ap...

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Problems solved by technology

[0007] It is noted that both BPSK and BOC use a discontinuous phase modulation scheme in the signal modulation process, that is, there is a 0 or 180 phase jump, which is beneficial to signal reception and related demodulation, but broadens the signal spectrum , which greatly increases the possibility of its interference

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