Modulator, demodulator, modulation method and demodulation method for low-frequency magnetic induction communication

Abstract

The invention provides a modulator, demodulator, modulation method and demodulation method for low-frequency magnetic induction communication. Therefore, problems of mutual restriction of a bandwidth and a Q value of the existing low-frequency magnetic induction communication transmitting terminal, low low-frequency communication rate, low integration degree and flexibility of the hardwire demodulation mode of the receiving terminal, and large calculation amount of the software demodulation mode in the prior art can be solved. According to the modulator, use data are successively processed by channel coding, BPSK digital modulation, D / A conversion and power amplification and then are inputted into a first series connection resonance loop; voltage physical reversing of the two ends of a first capacitor in the resonance loop is carried out at the time of phase changing of the loop current signal of the first series connection resonance loop, thereby avoiding the loop current signal attenuation. Therefore, the modulation signal bandwidth can be substantially improved on the premise that the Q value is maintained to be high; and the communication rate is improved.

Description

technical field [0001] The invention belongs to the modulation and demodulation technology in the communication field, and in particular relates to a modulator, a demodulator, a modulation method and a demodulation method for low-frequency magnetic induction communication. Background technique [0002] At present, low-frequency magnetic induction communication is widely used in underwater communication and underground communication because of its small antenna size, and it is not affected by multipath effect, propagation delay and fading during propagation. However, the channel under the low-frequency band is a low-rate channel, and how to make the most effective use of the communication channel is a difficult point in the current low-frequency communication technology. [0003] In the prior art, the common low-frequency resonant circuit in the transmitting end of low-frequency magnetic induction communication generally requires a trade-off between the bandwidth and the Q va...

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Problems solved by technology

[0005] The present invention provides a modulator, a demodulator, a modulation method and a demodulation method for low-frequency magnetic induction communication, which are used to solve the problem of low frequency communication rate due to the mutual limitation of the bandwidth and Q value of the transmitting end of the existing low-frequency magnetic induction communication. The hardware demodulation method at the receiving end has low integration and flexibility, and the software demodulation method has the problem of large amount of calculation

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