3 results about "Multipath interference" patented technology

The invention relates to the technical field of information security, in particular to a radio frequency fingerprint extraction and identification method capable of resisting multipath interference, which comprises the following steps of: firstly, simulating and generating wireless channel multipath parameters of a scene based on the working scene of wireless equipment; aiming at a specific application scene of wireless communication equipment, different methods are selected to simulate a multipath channel, then, signals which are collected in a training stage and are slightly influenced by multipath of the wireless channel at a short distance are simulated through a generated wireless channel model to obtain signals which are simulated and received through different wireless channels, andthen, different wireless channel simulation receiving signals are used as a training set of a radio frequency fingerprint identification classifier for training the classifier, and finally, the classifier trained based on using different wireless channel simulation receiving signals in advance is used for carrying out radio frequency fingerprint classification identification on signals actually transmitted through a wireless channel, and the influence of a wireless multipath channel on the radio frequency fingerprint can be effectively resisted.

The invention provides a method for demodulating a TCM-CPM signal under a multipath channel. The method comprises the implementation steps that a TCM-CPM modulator modulates a binary sequence, a frequency offset estimator performs frequency offset compensation on a modulation signal, a demodulator performs first viterbi demodulation on a frequency offset compensation signal, and then the demodulator performs second viterbi demodulation on the frequency offset compensation signal. In the second Viterbi demodulation branch metric calculation process, the demodulated code element, the current demodulation code element and the modulation signal corresponding to the first demodulation result serve as reference signals to be subjected to convolution with the channel gain value, the influence of multipath interference on the demodulation result can be restrained to the maximum extent, and the bit error rate is effectively reduced.