Method for generating direct-spread MSK (minimum shift keying) signals and conversion filter design method

Abstract

The invention provides a design method for a conversion filter generating direct-spread MSK (minimum shift keying) signals. The method comprises the following steps that a Chebyshev approximation convex optimization model of the conversion filter is built; the proper frequency sampling point number is determined, and the semi-infinite conditions of a conversion filter model is estimated by utilizing frequency sampling; the Chebyshev approximation convex optimization model is resolved, and a power spectral density function is solved; the filter order is selected, the power spectral density value of the conversion filter is calculated, and in addition, whether the power spectral density value meets the design requirements or not is judged according to the mean square error value; if the optimized power spectral density value meets the design requirements, the coefficient of the conversion filter is solved by a spectral factorization method through the power spectral density value. The design method for the conversion filter provided by the invention has the advantages that the filter order is smaller, and the occupied resources of hardware of the conversion filter are fewer.

Description

technical field [0001] The invention relates to the technical field of digital communication, in particular to the design of an all-digital modulator in a spread spectrum communication system and a device for generating direct spread MSK signals. Background technique [0002] The direct spread MSK signal has the advantages of low interception of the spread spectrum system, multi-user random site selection capability, and strong anti-interference performance, and the minimum shift keying (Minimum Shift Keying, MSK) signal has a constant envelope, high spectrum utilization, With the advantages of energy concentration, fast sidelobe attenuation, low out-of-band radiation power, and insensitivity to nonlinear distortion, it has been widely used in tactical data links, civil aviation ground-to-air data links, missile guidance command transmission, and satellite communications. [0003] Direct spread MSK signals are usually generated using an orthogonal parallel dual-channel struc...

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Problems solved by technology

[0005] In order to solve the problems existing in the prior art, the present invention provides a new direct-spread MSK signal generation device suitable for all-digital modulation / demodulation structures, which does not need to maintain strict time synchronization, amplitude balance and phase alignment of the two channels. The performance of the system is also well maintained, avoiding the defects of conventional direct expansion MSK signal generation and implementation, such as complex generation and implementation, taking up a lot of hardware resources, and not suitable for high-speed data transmission requirements.

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