4 results about "Costas loop" patented technology

The invention discloses a communication-detection integrated sonar signal design method and device based on multi-pulse composite modulation, and the method comprises the steps: dividing a total frame period into a detection sub-frame and a communication sub-frame, enabling the detection sub-frame to achieve the high-resolution distance measurement through employing a bidirectional linear frequency modulation (BILFM) signal, a communication sub-frame adopts a multi-frequency multi-phase composite modulation (MTPM) signal to realize high-bit-rate data transmission; after band filtering, orthogonal demodulation, low-pass filtering and down-sampling preprocessing are carried out on detection sub-frame echoes, distance and speed information is extracted by adopting fast-time low-sampling two-dimensional fast Fourier transform (2D-FFT), unambiguous Doppler frequency is recovered by utilizing the Chinese remainder theorem (CRT), and accurate speed measurement of long-distance and high-speed targets is realized; a communication subframe receiving signal is subjected to IQ demodulation after down-conversion, Costas loop carrier synchronization and matched filtering, and multi-frequency multi-phase coded data are extracted. According to the method, the time-frequency collaborative design of detection and communication is realized, the distance resolution and the speed measurement range are considered, and the signal bandwidth utilization rate and the underwater information transmission reliability are remarkably improved while the system complexity is kept low. The device comprises a processor and a memory, and an executable program for implementing the method is stored in the memory. The technology can be widely applied to the fields of unmanned underwater vehicles, ocean monitoring, underwater sensing networks and the like.

The application provides a three-phase inverter energy and information simultaneous transmission method and device based on a Costas loop, which is based on pulse width modulation to perform four-phase shift keying modulation on a carrier signal, embeds a transmission signal into voltage ripple through power switching tubes of a three-phase inverter, collects three-phase line voltage signals at a load side or a network side, and performs coherent demodulation based on Costas loop synchronization, including primary demodulation of a high-frequency switching frequency, secondary demodulation of a low-frequency three times fundamental frequency, differential decoding after symbol decision of two demodulation results, and finally parallel-serial conversion to obtain output data. Compared with a traditional method, the Costas loop synchronization demodulation technology can accurately track a carrier signal in real time, has good anti-interference ability, has a lower bit error rate, and has small damage to power quality by using a QPSK-PWM modulation method, so that high power quality and high communication accuracy can be realized for energy information simultaneous transmission.

This invention discloses a method and system for uplink single-carrier symbol correction in narrowband IoT based on a Costas ring, supporting the narrowband IoT protocol specifications defined in 3GPP Release 13. This invention combines the Costas ring with the characteristics of narrowband IoT uplink, utilizing software-defined radio equipment to acquire uplink single-carrier signals. By reconstructing the Costas ring structure, a nonlinear phase detector and a low-pass filter are jointly designed to form a loop filter with joint gain. A digital frequency synthesis module replaces the traditional voltage-controlled oscillator, dynamically compensating for symbol frequency offset and phase distortion based on the error signal output from the Costas ring, thereby completing the demodulation of the real narrowband RF signal. This invention solves the symbol distortion problem caused by frequency offset, multipath effects, and hardware nonlinearity in narrowband IoT scenarios, and can significantly reduce the communication bit error rate compared to traditional channel estimation schemes.

The invention discloses a phased array amplitude-phase calibration system and method based on a Costas loop, the system comprises a far-field calibration antenna, an analog circuit module and a channel module, the far-field calibration antenna transmits a calibration source signal to the analog circuit module, the analog circuit module outputs a signal to the channel module, and the channel module outputs the signal to the far-field calibration antenna. A signal is input into the channel module and then passes through the calibration module and the Costas loop module in sequence. The method is characterized in that the Costas loop is used for tracking the frequency difference and the phase difference of each channel in real time, corresponding frequency and phase compensation is automatically provided through the negative feedback loop without complex operation such as FFT, unification of the frequencies, the amplitudes and the phases of multiple channels is achieved, the Costas loop is introduced into a system architecture, and the frequency difference and the phase difference of the channels are greatly improved. The frequency and phase difference of the carrier and the reference signal in the input signal can be efficiently detected, meanwhile, compensation is automatically carried out, the flexibility of the system is improved, the full-digital design enables data processing and error value recording to be more flexible and convenient, and the overall efficiency of the system is improved.