The invention discloses a wireless aviation burst communication system, which comprises a burst frame construction module, a receiving digital front-end processing module, a burst detector, a carrier and phase parameter extraction and recovery module, and a timing parameter extraction and recovery module, wherein the burst frame construction module is used for constructing a burst frame, and the burst frame is composed of an AGC training sequence, two identical repeated CAZAC training sequences, and a data block; the receiving digital front-end processing module is used for acquiring an initial demodulation signal with frequency offset, phase offset and timing errors; the burst detector is used for adopting the repeated CAZAC training sequences for carrying out matched filter on the initial demodulation signal, acquiring a burst sign and outputting two related peak values and related peak sidelobe values; the carrier and phase parameter extraction and recovery module is used for estimating carrier and phase parameters and completing recovery; and the timing parameter extraction and recovery module completes timing recovery. The burst frame detection probability can be effectively improved, and complexity of burst communication carrier, phase and timing recovery is reduced.

Wireless aviation burst communication system

The invention provides a wireless data communication method and device, applied to the technical field of communication. The wireless data communication method comprises the following steps: generating a sequence set of preamble symbols, wherein the sequence set of the preamble symbols comprises coarse synchronization symbols and fine synchronization symbols; modulating a digital signal to be sentto generate a modulated signal, and inserting the sequence set of the preamble symbols before the modulated signal to form a transmitting signal; performing coarse synchronization and fine synchronization processing on a received signal to obtain the timing deviation, carrier frequency deviation and carrier phase of the received signal; performing timing recovery compensation processing on the received signal according to the timing deviation and carrier frequency deviation of the received signal; and performing carrier recovery on the received signal after the timing recovery compensation processing according to the carrier frequency deviation and the carrier phase. According to the invention, the coarse synchronization detection is carried out on the received signal first, and then thefurther fine synchronization detection is carried out on the received signal, which are based on the Chirp; therefore, the wireless data communication method can capture signals effectively under theworking condition of low SNR.

Wireless data communication method and device

The invention discloses a rapid carrier synchronization method for carrying out coherent demodulation on a FSK (Frequency Shift Keying) signal, which comprises the following steps of: 1, in the transmission process of a physical layer, when a receiver detects that a frame header arrives, carrying out demodulation operation on a received frame header waveform by using a locally generated or prestored frame header waveform so as to obtain a phase continuous simple-frequency signal; 2, estimating a frequency and a phase of the single-frequency signal by a method for estimating the frequency and the phase of the single-frequency signal; and 3, according to the estimated values, eliminating a frequency deviation and a phase of a received frame to obtain a received signal with a synchronized carrier In the transmission process of the physical layer, after one frame header is received, carrier frequency deviation and phase information contained in the received frame header is sufficiently extracted by adopting the method disclosed by the invention and the frequency deviation and the phase are used as compensation for carrier frequency deviations and phases of all received data of a current frame so as to enable application of coherent demodulation in the receiver to be possible, as a result, integral receiving performance of the receiver is improved

Rapid carrier synchronization method for carrying out coherent demodulation on burst transmission signal

The present invention relates to a nonlinear transformation-based phase-modulated signal frequency offset estimation and tracking method. According to the method, on the basis of theoretical analysison two-phase BPSK, four-phase balanced QPSK and unbalanced four-phase UQPSK modulated signals, primary nonlinear transformation or secondary nonlinear transformation is utilized to obtain symbol influence-removed radio frequency single-carrier signals, and therefore, preconditions are created for FFT (fast Fourier transform) spectrum analysis to realize carrier frequency offset estimation fast andaccurately. Compared with existing satellite technology which directly performs processing such as FFT spectrum analysis on phase-modulated signals, the method of the invention can assist solving technical shortcomings of dispersion of envelop spectrum peak points and large frequency offset estimation error and greatly improving the accuracy and real-time performance of frequency offset estimation and tracking of the phase-modulated signals, and has a bright application prospect in realizing carrier frequency offset estimation and tracking of phase-modulated signals of different links of a satellite.

Nonlinear transformation-based phase-modulated signal frequency offset estimation and tracking method

The present invention relates to frequency offset estimation methods based on frequency shift keying (FSK)/Gaussian FSK (GFSK)/minimum shift keying (MSK)/Gaussian MSK (GMSK) modulation, a transmitter, a receiver, and a communication system. A preamble sequence consisting of set symbols can be set as a preamble signal of a baseband complex signal, power spectrum analysis is performed on the preamble signal so as to estimate a frequency offset value of the baseband complex signal, and the receiver does not need to generate or pre-store the preamble signal, nor perform demodulation operation on the received preamble signal, so that the complexity of the algorithm and the communication system is lowered. In addition, the preamble sequence consisting of the same symbols improves the redundancy and anti-interference capability of the preamble signal, so that a frequency offset estimation result calculated according to the preamble signal is more accurate.

Frequency offset estimation methods, transmitter, receiver and communication system

The invention discloses a quick carrier synchronizing method for FSK (Frequency Shift Key) signal coherent demodulation, which comprises the steps: 1) carrying out a demodulating operation for a received lead sequence by using a lead sequence waveform generated locally or pre-stored when a receiver detects that the lead sequence arrives in a transmission process of a physical layer to obtain a single-frequency signal with continuous phase; 2) estimating the frequency and phase of the section of the single-frequency signal through estimation of the frequency and phase of the single-frequency signal; and 3) eliminating the frequency deviation and phase of a received frame to obtain a received signal with synchronized carrier according to the estimated value. In the transmission process of the physical layer, after the lead sequence is received, the frequency deviation and phase information comprised in the received lead sequence is adequately extracted and the frequency deviation and phase are applied to compensation of the frequency deviation and phase of all received data by current frame so that coherent demodulation can be possibly applied to the receiver, thereby, the overall receiving performance of the receiver is further improved.

Hong Li

Papers

Quick carrier synchronizing method for FSK signal coherent demodulation