40results about How to "Avoid nonlinear distortion" patented technology

A random access channel transmission method in which a user terminal selects a preamble pattern from among a plurality of known preamble patterns and transmits that preamble pattern to a base station, where that transmission method comprises: a step of dividing a cell into a plurality of areas, and setting one or more preamble patterns and the number of repetitions for transmitting the preamble pattern for each area; and a step wherein a user terminal that exists in an are close to the base station transmits a specified preamble pattern one time, and a user terminal that exists in an area far from the base station transmits another specified preamble pattern a plurality of times.

A method for registering patterns on a web to provide independent scale control in both the lateral and longitudinal directions is provided. The method includes routing the web over a first roller; routing the web over a second roller and stabilizing the web; applying a pattern to the web using process hardware; measuring registration of the pattern and providing an error signal; controlling lateral position error using the error signal; controlling longitudinal position error using the error signal; controlling lateral scale error using the error signal; and controlling longitudinal scale error using the error signal. The method provides independent scale control in both the lateral and longitudinal directions. Independent scale control avoids non-linear distortions otherwise imposed by attempting to accomplish both corrections by stretching the web in both directions.

A method for registering patterns on a web to provide independent scale control in both the lateral and longitudinal directions is provided. The method includes routing the web over a first roller; routing the web over a second roller and stabilizing the web; applying a pattern to the web using process hardware; measuring registration of the pattern and providing an error signal; controlling lateral position error using the error signal; controlling longitudinal position error using the error signal; controlling lateral scale error using the error signal; and controlling longitudinal scale error using the error signal. The method provides independent scale control in both the lateral and longitudinal directions. Independent scale control avoids non-linear distortions otherwise imposed by attempting to accomplish both corrections by stretching the web in both directions.

A device for receiving a RF signal (1; 21) with loop-through output (16) is provided. The device comprises: an input (3) receiving a RF input signal (2); an analog- digital converter (8) converting the RF input signal (2) to a digital signal (9); a digital signal processing unit (10) digitally processing the digital signal (9); a digital-analog converter (14) converting the processed digital signal (13) to a loop-through RF signal (15) corresponding to the RF input signal (2); and a loop-through output (16) outputting the loop-through RF signal (15).

The invention provides a link control method and device and belongs to the wireless field. The method comprises the following steps that: first link quality is obtained; a new modulation mode to be used is determined according to the first link quality; current transmitting power is obtained; and if the current transmitting power can make microwave transmission equipment work normally under the new modulation mode, the new modulation mode is determined as a current modulation mode, otherwise, an original modulation mode is kept as the current modulation. With the link control method and device of the invention adopted, nonlinear distortion occurring under a high-order modulation mode, which is caused by discordance of the effects of automatic modulation (AM) and automatic transmit power control (ATPC), can be avoided, and at the same time, it can be ensured that a low-order modulation mode can exert larger transmission power.

During digital transmission using existing non-linear AM emitters, spurious emissions occur as a result of the non-linear distortions, in turn causing inner band disturbances and also disturbing adjacent channels, as out-of-band radiation. Non-linear distortions are especially critical for digital multiple carrier signals (e.g. OFDM) which are recommended by the ITU with the DRM system for the AM area. In order to avoid the non-linear distortions, the end step of the AM emitter is operated in the linear mode, thus ensuring the ITU spectrum mask. The relatively low efficiency of the emitter during the linear operation can be improved by tracking the distribution voltage of the emitter end step according to the drive. To this end, the envelope of the complex modulated data signal is scanned, and said signal controls the distribution voltage for the emitter end step by means of the modulator operating as a switched-mode power supply unit.

An embodiment of the invention provides a data receiving terminal in a network data transmission system. The network data transmission system further comprises a front data transmission terminal, a transmission network and an access network. The front data transmission terminal comprises a convergence switch, a transceiving port of the convergence switch is forcedly set to transmit only, and the front data transmission terminal is used for encoding and IP (internet protocol) packing of audio-video data and the like and outputting an IP data packet in an IP broadcasting or multicast mode via the convergence switch. The transmission network is a cable television broadcasting network which is used for unidirectional and transparent transmission of the IP packet at the speed of 1Gb or above. The access network comprises a first switch and is used for obtaining the IP data packet from the transmission network via the first switch which is a broadcasting switch or a multicast switch. The data receiving terminal is used for obtaining the IP data packet from the access network and unpacking and decoding the IP data packet so as to play the audio-video data.

The invention discloses a decoding method and system of a CPM-based RCM coding method, belonging to the technical field of rate-adaptive transmission in wireless communication. RCM coding symbols obtain a constant envelope signal with a peak-to-average ratio of 0 dB through CPM modulation; The BP method performs multiple internal iterations, and continuously updates the message from the coded symbol to the random signal and the message from the random signal to the coded symbol. When the maximum number of iterations is reached, the prior probability corresponding to the output coded symbol is passed to the CPM demodulator, according to The prior probability of the coded symbol transmitted is updated and the maximum posterior probability of the coded symbol is passed to the RCM decoder to update the message from the coded signal to the random signal to obtain the probability of the random signal taking the value of 0 and 1. The invention avoids the problem that the RCM high-power signal falls in the nonlinear region of the power amplifier and produces nonlinear distortion.

The invention provides a step wave generating circuit which comprises a counting module and a digit-to-analogue conversion module. The counting module is used for counting a periodic pulse signal, t output ends of the counting module are respectively connected with t input ends of the digit-to-analogue conversion module, wherein the (n+1)th output end of the counting module is connected with the (m+1)th input end of the digit-to-analogue conversion module, n is the lowest digit of the output ends of the counting module, the output ends of the counting module are connected with the digit-to-analogue conversion module, and m is the lowest digit of the input ends of the digit-to-analogue conversion module, and the input ends of the digit-to-analogue conversion module are connected with the counting module. Due to the fact that the counting module conducts counting on the periodic pulse signal, the digit-to-analogue conversion module converts a count value of the counting module into an ji signal to produce the step wave signal. Therefore, no diode is used in the step wave generating circuit, non-linear distortion produced by influence of temperature of the diode is avoided, and therefore precision of the produced step wave is improved.

The invention discloses a fingerprint identification sensor and a fingerprint identification method, which include a fingerprint image sensing array for detecting finger touch, including a plurality of driving electrodes and sensing electrodes arranged in an appropriate manner, and a processor, which Cooperate with the sensing array, scan the sensing array and generate a complete fingerprint image based on the sensing signal, which generates different modulation signals and applies them to multiple driving electrodes to obtain a composite signal, and uses the modulation signal to Sensing signals of the sensing electrodes are demodulated to obtain electrical sensing signals indicating fingerprint information, and a complete fingerprint image is generated by processing the sensing signals. The invention effectively reduces the number of pins of the processor circuit chip package through the multiplexing of the electrodes, reduces the crosstalk and coupling between the sensing signals of the sensing electrodes, and optimizes the system design.

The invention discloses a power operation monitoring system for a 5G communication base station, which includes a power operation acquisition module, a control module and a wireless transmission module. The power operation acquisition module includes a power parameter acquisition circuit, an operational amplifier frequency selection circuit, a measurement protection circuit and a peak detection circuit , in the op amp frequency selection circuit, the op amp AR1 performs secondary amplification on the detection signal, effectively avoiding the nonlinear distortion caused by signal amplification, and at the same time adding a third-order bandpass filter for frequency selection, which eliminates the op amp process. The noise interference mixed in; the measurement protection circuit and the peak detection circuit are designed to measure the two key parameters of the frequency and amplitude of the detection signal respectively, so that the detection results are more stable and reliable, and the ARM microcontroller will collect the data through GPRS wireless transmission The module is sent to the monitoring server for monitoring and management, so as to realize remote monitoring of the power operation of the 5G communication base station, and has good reliability, fault diagnosis and system monitoring capabilities.

The invention discloses a PLL filter. A radio frequency intrinsic signal the frequency of which is the same as the frequency of a final radio frequency output signal is connected with an intrinsic drive module in an external connection way to generate two paths of quadrature radio frequency intrinsic signals, then a baseband signal I and Q components connected in the external connection way are performed with frequency up-conversion by a quadrature mixer, a modulation signal modulated to the radio frequency carrier frequency is obtained and directly used as the input of a radio frequency limiter, the other input of the radio frequency limiter is a feedback signal of the final radio frequency output signal, the two paths of input signals are limited by the radio frequency limiter, then thephases of the two paths of input signals are compared according to the frequency of the radio frequency by a radio frequency phase detector, an upper charge signal or a lower discharge signal is generated to control the output of a fully differential charge pump, fully differential control voltage is output to control the oscillation frequency of a differential voltage controlled oscillator via afully differential low-pass filter, and the final radio frequency output signal is output. The PLL filter has the advantages of small nonlinear distortion and little stray emission in the output frequency spectrum.