Signal transmitting method and signal receiving method based on TDCS (Transform Domain Communication System) differential transmission

Abstract

The invention discloses a signal transmitting method and a signal receiving method based on TDCS (Transform Domain Communication System) differential transmission. The method comprises the following steps: acquiring a first frequency domain basic waveform vector by using a first frequency spectrum mask sequence and a first random phase complex sequence; performing inverse fast Fourier transform on the first frequency domain basic waveform vector to obtain a time domain basic modulation waveform; performing imaginary transformation on the time domain basic modulation waveform serving as a first path basic modulation waveform to obtain a second path basic modulation waveform; extracting k bits of bit data to be transmitted, and acquiring the decimal system mapping value of the k bits of bit data to be transmitted according to a rightmost bit as highest bit principle; randomly acquiring a first decimal numeral and a second decimal numeral; acquiring a first path modulation waveform and a second path modulation waveform through shift circulation modulation; synthesizing the first path modulation waveform and the second path modulation waveform to obtain a transmission signal, and transmitting the transmission signal by using an orthogonal frequency-division multiplexing transmission module.

Description

technical field [0001] The invention relates to the field of transform domain communication, in particular to a signal sending method and a signal receiving method based on tDCS system differential transmission. Background technique [0002] With the rapid development of wireless communication, the use of spectrum resources is becoming more and more tense. Transform Domain Communication System (TDCS), as an alternative technology for Cognitive Radio (CR), can realize spectrum Rational use of resources. [0003] TDCS detects the utilization of the current frequency band, synthesizes the corresponding fundamental modulation waveform (Fundamental Modulation Waveform, FMW) in the frequency domain, and then loads data based on the FMW, so as to avoid affecting the current users and effectively use the current idle frequency band for communication transmission. There are two key technologies in TDCS: Pseudo Phase Mapping (PPM) and Cyclic Code Shift Keying (CCSK). PPM enables th...

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Problems solved by technology

[0024] However, the above-mentioned TDCS system in the prior art, on the one hand, only extracts the real part of the PCF when receiving and detecting, and discards the imaginary part, so there is a problem of wasting spectrum resources; It is directly transmitted without processing. Therefore, once the data is intercepted, the information will be exposed, and the communication security is extremely low.

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