10 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 present invention discloses a DSSS enhanced synchronization method combining PMF-FFT and an improved Costas loop, which is applied to the field of wireless communication technology. Traditional receiver designs typically employ independent frequency offset estimation and carrier synchronization methods, which are unsuitable for processing high-dynamic environments and low signal-to-noise ratio conditions. The present invention employs a maximum frequency offset estimation algorithm based on a partially matched filter-fast Fourier transform. By performing an FFT transform on the received signal, the frequency offset of the signal is accurately estimated, thereby effectively reducing the impact of the frequency offset on synchronization performance. Based on the frequency offset estimation, the receiver system designed in the present invention incorporates a Costas loop for carrier synchronization tracking. High-precision carrier recovery is achieved by locking the phase of the input signal.

A method for operating an optical demodulator includes receiving a double sideband suppressed carrier (“DSBSC”) optical signal. The method further includes passing the DSBSC optical signal through a Costas loop circuit. The method further includes outputting a radio frequency (“RF”) signal from a quadrature port of the Costas loop circuit.

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.

According to the present disclosure, an RF communication system using a bi-directional plastic waveguide link is suggested. The system may comprise: an RF transmitter configured to up-convert a transmission signal to a carrier frequency, and transmit same; an RF receiver configured to down-convert a reception signal received on the carrier frequency, and receive same; a bi-directional plastic waveguide device configured to provide a channel for transmission of the transmission signal and a channel for reception of the reception signal; and a microstrip-to-waveguide transition (MWT) configured to transfer a signal between the RF transmitter or the RF receiver and the bi-directional plastic waveguide device. The RF receiver may comprise: a phase detector configured to detect the phase of the down-converted reception signal by using a clock signal; and a phase synchronization device configured to regulate the phase of the clock signal on the basis of the detected phase. Through such configuration, the present disclosure may suggest a 50 GB / S PAM4 bi-directional plastic waveguide link having carrier synchronization using a PI-based Costas loop, which can exhibit very excellent performance from the perspective of a throughput-distance and energy efficiency, compared to conventional technology.

The invention discloses a Costas ring-based narrow-band Internet of Things uplink single carrier symbol correction method and a Costas ring-based narrow-band Internet of Things uplink single carrier symbol correction system, which support a narrow-band Internet of Things protocol specification specified in 3GPP (3rd Generation Partnership Project) Release 13. According to the invention, the Costas loop is combined with the uplink characteristics of the narrowband Internet of Things, the software radio equipment is used for collecting uplink single-carrier signals, the Costas loop structure is reconstructed, a nonlinear phase discriminator and a low-pass filter are designed in a combined manner, and a loop filter with combined gain is formed. A digital frequency synthesis module is adopted to replace a traditional voltage-controlled oscillator, symbol frequency offset and phase distortion are dynamically compensated based on error signals output by a Costas loop, and therefore demodulation of real narrowband radio frequency signals is completed. According to the method, the problem of symbol distortion caused by frequency offset, multipath effect and hardware nonlinearity in a narrowband Internet of Things scene is solved, and compared with a traditional channel estimation scheme, the communication error rate can be remarkably reduced.

This invention discloses a general-purpose, lightweight coherent demodulation receiver and demodulation method with continuous phase modulation. It suppresses local oscillator phase noise at the RF source using ADPLL and compresses the overall frequency offset to within ±10kHz using differential autocorrelation coarse frequency offset estimation, providing a stable frequency offset foundation for subsequent high-precision coherent demodulation. A second-order digital Costas closed-loop carrier tracking loop, coupled with a configurable FFE-DFE equalization module, is employed to compensate for residual frequency offset and eliminate inter-symbol interference of GMSK signals with different BT parameters in real time using a purely digital, matrix-operation-free, low-area incremental approach. The GMSK signal is converted into a simplified PSK constellation through constellation correction and equivalent mapping techniques, and differential decoding eliminates the 0 / π phase ambiguity of the Costas loop, outputting the correct bitstream without the need for extended preambles or dedicated pilots. This method not only retains the high sensitivity advantage of coherent demodulation but also reduces baseband logic area and processing complexity, achieving a balance between high performance and lightweight design.

The invention discloses an arc tangent Costas ring based on low-frequency time code synchronization and a carrier synchronization method, and relates to the technical field of information processing of low-frequency time codes. The arc tangent Costas loop based on low-frequency time code synchronization comprises a first multiplier, a first low-pass filter, a second multiplier, a second low-pass filter, an arc tangent phase discriminator, a loop filter, a voltage-controlled oscillator and a # imgabs0 # phase shifter. By implementing the arc tangent Costas ring based on low-frequency time code synchronization and the carrier synchronization method provided by the invention, the phase tracking speed and efficiency can be improved.