Coherent pseudo code ranging method based on MSK (minimum shift keying) spread spectrum modulation mode

Abstract

The invention discloses a coherent pseudo code ranging method based on an MSK spread spectrum modulation mode, and relates to the technical field of communication. The method is based on MSK spread spectrum demodulation, a base band ranging pseudo code of a signal is embedded in a communication information code, the ranging is performed at a receiving terminal, two-time coarse ranging and one-time refined ranging are adopted for ranging during the whole process, and a novel filtering mode is adopted during code element synchronization process simultaneously. The method has the benefits as follows: ranging frames are embedded into information frames under the conditions that a communication channel bandwidth is not increased and an original information rate, a spreading code rate and the a MSK modulation mode are not changed, so that long-distance and high-accuracy ranging is realized simply, conveniently and rapidly; the system is operated under the MSK modulation mode and has stronger capacity of resistance to interference and capture; and besides, an improved filtering method is adopted in the code element synchronization method so as to solve the problem of overlarge phase deviation of a bit synchronization pulse, and phase adjustment time is shortened simultaneously.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a coherent pseudo-code ranging method based on MSK spread spectrum modulation mode. Background technique [0002] Traditional radio ranging methods mainly include: pseudo-code ranging, continuous wave ranging, frequency modulation ranging, pulse ranging and multi-tone phase ranging. [0003] Among the traditional ranging methods, the time-of-arrival method is widely used, and the distance is estimated by measuring the delay of the radio wave reaching the antenna. Because the propagation speed of radio waves in the air is constant, as long as the time delay value is obtained, the measurement distance can be obtained. [0004] The ranging system adopts the rangefinder and the transponder. The rangefinder transmits the ranging signal transmitted by the rangefinder through the transmitting channel, space transmission, and the transponder responds. The receiving channel receive...

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Problems solved by technology

Pseudo-code ranging is limited by the processing chip sampling rate, chip length, and signal bandwidth. If the sampling rate is increased, the hardware cost will be greatly increased. If the selected spreading code is too long, it will increase the difficulty of signal calculation and prolong the information processing time. If the chip rate is increased, the signal bandwidth needs to be increased. Therefore, in the traditional method, it is impossible to achieve both long-distance and high-precision ranging

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