68 results about "Digital up converter" patented technology

Digital Transceiver (DTRX) usable in a radio communications systems for transmitting and receiving digital base-band signals, wherein the DTRX (300) comprises: at least one digital up-converter (DUC) (310) for transmitting digital base-band signals and at least one digital down-converter for receiving digital base-band signals. In one aspect of the teachings disclosed herein the DUC (310) comprises at least two over-sampling units (314, 315), at least one quadrature modulation unit (340), and at least one time-discrete sigma delta band-pass modulator (318). The digital down-converter comprises at least one quadrature demodulation unit (360), at least two decimator units (356,357), and at least two sub-sampling units (354, 355). The digital base-band signal comprises an in-phase component (I-signal) and a quadrature component (Q-signal).

A digital transmitter (20) that may be advantageously used in a high-frequency transceiver, such as a wireless telephone handset, is disclosed. The transmitter (20) includes digital upconverter functions (36I, 36Q) that operate in combination with a digital band-pass sigma-delta modulator (40) to generate modulated digital signals at a sample frequency that is a multiple of the transmit frequency. The digital band-pass sigma-delta modulator (40) applies a noise transfer function in a feedback filter (72) in which the center of the pass band corresponds to the transmit frequency, and in which notches in the characteristic can be symmetrically or asymmetrically selected to correspond to specific frequencies, such as the receive band frequency, in which transmit noise is to be minimized. A combined FIR digital filter (42) and MOS power switch array (44) is also disclosed, in which a cascode arrangement of drain-extended MOS power transistors (78) and switching transistors (82) provide the output RF signal, with a coarse gain control (80) applied.

A module for an active antenna system for receiving and transmitting radio signals sealed in a housing. It comprises a power connector placed at the outside of the housing for supplying the module with supply power; at least one micro radio for receiving / sending digital radio signals having a digital down-converter / a digital up-converter and a control signal converter. The micro radio converts the digital radio signals to analogue RF (radio frequency) signals and vice versa and is connected to the internal bus. At least one antenna element is connected to the micro radio and an internal data bus for the exchange of digital radio data and control data is connected to micro radio and hub. By placing two or more modules next to each other on a frame these modules form an active antenna system.

A system and method for enhancing the performance of wideband digital RF transport systems is disclosed, which enables the transport of different bandwidth segments on a plurality of wideband channels by selecting an optimal clock sample rate for each bandwidth segment to be transported. Thus, the bandwidth segments are proportionally allocated so that an optimum amount of bandwidth can be transported at the serial bit rate. As one example, a system for enhancing the performance of a wideband digital RF transport system is disclosed, which includes a transmit unit, a receive unit, and an optical transmission medium connected between the transmit unit and the receive unit. The transmit unit includes a plurality of wideband RF analog signal inputs coupled to a plurality of analog-to-digital, digital down-converter (A / D DDC) devices. Notably, the sample rate of each A / D DDC device is determined by a respective sample clock. The digitized wideband RF segments at the outputs of the A / D DDC devices are combined and converted to a frame structure, converted to serial form, and transmitted on the optical transmission medium to the receive unit. A light detector device in the receive unit detects the serial bit stream on the optical transmission medium, the serialized frames are converted back to the original frame format, and the original digitized wideband RF segments are reconstructed. Each digitized wideband RF segment is coupled to a respective D / A digital up-converter (D / A DUC) device associated with a particular wideband RF signal input on the transmit side. Notably, the output sample rate of each D / A DUC device is determined by a respective sample clock, which provides the same sample rate as that of the associated A / D DDC device in the transmit unit. The sample rate of each A / D DDC device (and associated D / A DUC device) is pre-selected so that the transmission medium can transport the optimum amount of RF bandwidth at the given serial bit rate.

A digital transmitter (20) that may be advantageously used in a high-frequency transceiver, such as a wireless telephone handset, is disclosed. The transmitter (20) includes digital upconverter functions (36L, 36Q) that operate in combination with a digital band-pass sigma-delta modulator (40) to generate modulated digital signals at a sample frequency that is a multiple of the transmit frequency. The digital band-pass sigma-delta modulator (40) applies a noise transfer function in a feedback filter (72) in which the center of the pass band corresponds to the transmit frequency, and in which notches in the characteristic can be symmetrically or asymmetrically selected to correspond to specific frequencies, such as the receive band frequency, in which transmit noise is to be minimized. A combined FIR digital filter (42) and MOS power switch array (44) is also disclosed, in which a cascode arrangement of drain-extended MOS power transistors (78) and switching transistors (82) provide the output RF signal, with a coarse gain control (80) applied.

The invention discloses a mobile communication direct amplifying station with digital intermediate frequency. Wherein, transforming the down signal into analog intermediate frequency signal with RF module to send to ADC / DAC group and transform into digital intermediate frequency signal by A / D; extracting and filtering with digital down converter, and secondary transforming into baseband signal to send to baseband treatment unit for packaging into serial data as given frame format; transferring with optical fiber to high-speed digital optical fiber transceiver on cover end to de-frame with baseband treatment unit and send into ADC / DAC group; filtering and interpolating with digital up converter, transforming into analog intermediate frequency signal by D / A converter; finally, taking frequency conversion with RF module into RF signal and sending to opposite over area. The remote machine sends received up signal of mobile terminal with said inverse process to receiving end of base station. This invention avoids intrinsic leakage and dc offset in prior art.

A cable modem is provided. The cable modem may include: a plurality of modulators to generate a plurality of pieces of digital data corresponding to a plurality of independent channels; a plurality of digital upconverters to up-convert a frequency of each of the plurality of pieces of digital data into a predetermined frequency; and a Radio Frequency (RF) processor to channel-bond outputs of the plurality of digital upconverters into at least one channel, and generate an analog output signal, the outputs having the predetermined frequency.

The invention discloses a short-wave radio frequency digital processing module which mainly comprises a receiving radio frequency analog front end, a receiving radio frequency digital front end and an emission submodule, wherein the receiving radio frequency analog front end comprises a harmonic filter, a broadband low-noise amplifier with automatic gain control (AGC) and a low-pass filter; the receiving radio frequency digital front end comprises an analog / digital (A / D) conversion circuit, a digital down converter (DDC), a direct digital frequency synthesizer (DDS) and a digital signal processor (DSP); and the emission submodule comprises a digital / analog (D / A) conversion circuit, a digital up converter (DUC), a DDS and a DSP. The short-wave radio frequency digital processing module of the invention can simplify the design structure of a shortwave radio station, reduces the types of radio stations, improves the service life of the digital shortwave radio station, and reduces the input cost of users.

A direct conversion receiver with an integrated self alignment tuner. The system includes a tank circuit, an analog to digital converter, a digital down converter, a digital up converter, a local oscillator, and a digital to analog converter. The tank circuit receives a radio frequency signal from an antenna input. The analog to digital converter is connected to the tank circuit to digitize the tank output signal and generate a corresponding digital signal. The digital down converter is in communication with the analog to digital converter and generates an intermediate frequency signal based on the digital signal and the output of the local oscillator. The digital up converter is in communication with the digital to analog converter to generate a radio frequency test signal, where the digital to analog converter provides the radio frequency test signal to the antenna input.

The invention discloses a multimode radio frequency signal generator, comprising a personal computer as well as a baseband I, a Q signal generator, a multi-carrier digital up-converter subsystem, a D / A converter, a clock subsystem and a microchip control subsystem that are respectively connected with the multimode radio frequency signal generator; wherein, the baseband I and the Q signal generator are connected with the multi-carrier digital up-converter subsystem, the D / A converter and a radio frequency subsystem in sequence; the clock subsystem is simultaneously connected with the baseband I, the Q signal generator, the multi-carrier digital up-converter subsystem, the D / A converter, the radio frequency subsystem and the microchip control subsystem; the microchip control subsystem is connected with the baseband I, the Q signal generator, the multi-carrier digital up-converter subsystem, the D / A converter and the radio frequency subsystem at the same time; the radio frequency subsystem is provided with a multimode multi-carrier radio frequency signal output end. The multimode radio frequency signal generator has the advantages of excellent performance, good feasibility, strong system flexibility and expandability as well as easy realization of system miniaturization and low power consumption.

A transmitter includes a first digital up-converter for converting data to an intermediate frequency (IF) signal, a pulse width modulator (PWM) for encoding the IF signal to an IF pulse train, a second digital up-converter for converting the IF pulse train to a radio frequency (RF) pulse train, a power amplifier for amplifying the RF pulse train; and a filter for reconstructing a RF analog signal from the amplified RF pulse train.

The invention provides an antenna arraying full-spectrum correlated combining system based on a broadband signal frequency domain and aims to provide a frequency domain based arraying system capable of saving hardware computing resources and overcoming phase ambiguity. The technical scheme includes that the antenna arraying full-spectrum correlated combining system is implemented according to that an A / D (analog / digital) module is used for sampling inputted broadband medium-frequency analog signals; obtained digital medium-frequency signals are subjected to sampling clock full-period delay by a delay module according to N antenna signal time delay estimation values fed back by a correlated combining module, then subjected to frequency conversion by a DDC (digital down converter ) module, polyphase decomposition by an analysis module to obtain M falling-rate narrow-band branches with uniform frequency domain ranges, polyphase correlation, time delay estimation and feedback, fractional time delay correction and polyphase combining by a correlated combining module, polyphase synthesis by a synthesis module, and finally are outputted to a demodulation receiver through a DUC (digital up converter) module and a D / A (digital / analog) module. The antenna arraying full-spectrum correlated combining system based on the broadband signal frequency domain solves the problem of phase ambiguity through integer multiples of sampling clock delay and fractional delay compensation.

A digital up-converter (DUC) circuit for performing digital channel filtering of an incoming baseband digital signal. The proposed circuit reduces the complexity of the channel module filter of the DUC. This is achieved by taking advantage of the structure of the underlying symbol waveforms carried by the incoming baseband digital signal which have one or more known discontinuities comprising random amplitude and / or phase. Namely, the channel filter module is activated only for the digital samples located around the known discontinuities and is deactivated for the remaining digital samples. Further, the switching of the channel filter module from one state to another can be performed according to a smooth function so that further discontinuities are not introduced in the incoming baseband digital signal. A method and a computer program are also disclosed.

A radio frequency (RF) receiver is provided, comprising an antenna, a low noise amplifier, a down converter, a first analog to digital converter (ADC), a second ADC, a digital up converter. The antenna receives an RF signal, and the LNA coupled to the antenna amplifies the RF signal. The down converter, coupled to the LNA, down converts the RF signal to generate an in-phase baseband signal and a quadrature baseband signal. The first ADC, coupled to the down converter, digitizes the in-phase baseband signal to an in-phase digital signal. The second ADC, coupled to the down converter, digitizes the quadrature baseband signal to a quadrature digital signal. The digital up converter, coupled to the first and second ADCs, up converts the in-phase digital signal and quadrature digital signal to generate an intermediate frequency (IF) signal.

The invention relates to the field of liquid level measurement device, specifically a method of liquid level measurement with radar and radar liquid level instrument with this method. To solve the current problems of low accuracy of measurement result and high cost, the invention employs the technical project: a method of liquid level measurement with radar, the liquid level to be measured can be obtained based on the formula L=H-c1(Deltphi11 / 4 piDeltf1); a radar liquid level instrument with this method includes radio-frequency unit, transmitting element, receiving element and processing unit, radio-frequency unit includes reference clock source and clock source, reference clock source is connected with the clock source in radio-frequency unit; said transmitting element comprises digit up converter, D / A converter and low-pass filter, said receiving element includes low-pass filter and digit down converter and D / A converter.

The invention discloses a calibration system and method for the amplitude-phase error of a receiving channel of a spaceborne DBF (Digital Beam Forming) network. The system comprises a calibration signal generating module, a calibration signal transmitting module, a receiving channel and calibration interface module, and a calibration algorithm execution module, wherein the calibration algorithm execution module comprises an amplitude-phase error estimator and a calibration factor generator; the calibration signal generating module comprises an orthogonal pseudo random code block generator and a BPSK (Binary Phase Shift Keying) modulator; the calibration signal transmitting module comprises a digital up converter, a DA inverter, an analog up converter and a calibration feed source; the calibration signal generating module is connected with the calibration signal transmitting module; and the calibration algorithm execution module is connected with the receiving channel and calibration interface module. The system and the method provided by the invention have the advantages of strong real-time performance, high precision and high stability, and save satellite resources.

The invention provides a digital down converter and a digital upconverter. Intermediate-frequency signals are mixed by a first-level mixing module in the digital down converter; two paths of I / Q mixing signals are output in a two-carrier time division multiplexing mode; a first-level multi-rate conversion module and a second-level multi-rate conversion module synchronize clock frequency before extraction; and the received signals are subjected to multiple extraction and filtration in a multi-carrier time division multiplexing mode according to the synchronized clock frequency. The digital upconverter synchronizes the clock frequency before frequency interpolation; a third-level multi-rate conversion module, a fourth-level multi-rate conversion module, a second-level mixing module and a fifth-level multi-rate conversion module perform frequency interpolation and filtration on the received signals in the multi-carrier time division multiplexing mode according to the synchronized clock frequency and the received signal data rate. The converter reduces the complexity of a control signal and saves logical resources.

The invention provides a repeater station carrier fluctuation calibration method which comprises the steps of generating a carrier signal of which the amplitude is a constant and transmitting the carrier signal to a digital up converter module, counting the carrier output power of an output signal of the digital up converter module, calculating the power difference between the carrier output power and a corresponding carrier feedback power and calibrating a gain compensation parameter of a corresponding carrier in the digital up converter module according to the power difference. The invention further provides a repeater station carrier fluctuation calibration device. By the adoption of the technology of the invention, a direct-current signal source can be generated inside a repeater station, fluctuation calibration can be carried out without configuring signal source equipment, the operation is flexible, the efficiency is high, the fluctuation calibration process is greatly simplified, the direct-current signal waveform is smooth, and the direct-current signal source can be used as a signal source for fluctuation calibration to obtain a higher calibration accuracy.

The invention discloses a CDMA communication anti-interference system based on frequency domain filtering. The CDMA communication anti-interference system comprises a signal preprocessing portion, a frequency domain processing portion and a post-processing portion, wherein the signal preprocessing portion comprises an A / D collector, a digital down-converter, a low-pass filter and an extractor which are connected in sequence; the frequency domain processing portion comprises two routes, one route comprises a windowing device, an FFT device, a threshold value generating and spectral line processing device, an IFFT device and 50% delay device which are connected in sequence, the other route comprises a 50% delay device, a windowing device, an FFT device, a threshold value generating and spectral line processing device and an IFFT device which are connected in sequence, and finally, the two routes are connected with an adding device simultaneously; the post-processing portion comprises an interpolation device, a filter, a digital up-converter and a D / A converter which are connected in sequence. The invention further discloses a CDMA communication anti-interference method based on frequency domain filtering. By means of the system and the method, the anti-interference ability of the system is effectively enhanced.

Antenna system connectable to a base station, the antenna system comprising a digital radio unit connectable to at least one antenna element, wherein the digital radio unit comprises: at least one micro radio for receiving / sending digital radio signals having a digital down-converter / a digital up-converter and a digital signal converter. The at least one micro radio converts the digital radio signals to analogue RF (radio frequency) signals and vice versa. The at least one micro radio has at least one hub for processing digital radio signals and control signals and for routing said digital radio signals and control signals via at least one serial link and at least one interface. The at least one serial link is provided between the at least one hub and the at least one micro radio.

The invention provides a self-adaptive interference cancellation control device which is used in wireless same-frequency relay equipment. The self-adaptive interference cancellation control device comprises an adder / subtractor, an automatic gain control module, an adaptive filter, an interference canceller and a delayer. One input end of the adder / subtracter is connected with a digital down converter in the wireless same-frequency relay equipment; the output end of the adaptive filter is connected with the other input end of the adder / subtracter through the interference canceller; the output end of the adder / subtractor is connected with the input end of the automatic gain control module, one output end of the automatic gain control module is connected with the input end of the self-adaptive filter through the delayer, and the other output end of the automatic gain control module is connected with a digital up-converter in the wireless same-frequency relay device. The invention furtherprovides a self-adaptive interference cancellation wireless same-frequency relay system and a self-adaptive interference cancellation control method, and the self-excitation problem of the wireless same-frequency relay equipment can be effectively solved.

The invention discloses a method for testing a satellite mobile communication terminal digital up-converter. A PC (Personal Computer) machine is connected with an FPGA (Field Programmable Gate Array) in the digital up-converter, the FPGA is controlled to generate I / Q (In-phase / Quadrature) data of an analog baseband signal and the I / Q data is input into an AD9957 chip to be converted into an analog signal to output; the analog signal output by the AD9957 chip enters an SAW (Surface Acoustic Wave) filter by a first RF (Radio Frequency) transformer and a first spectrum analyzer is connected between the first RF transformer and the SAW filter; and an output signal of the SAW filter enters an AD8370 chip by a second RF transformer, an output signal of the AD8370 chip is output by a third RF transformer and a second spectrum analyzer is connected to the output end of a third RF amplifier. By utilizing testing equipment such as the PC machine, the spectrum analyzers and the like, various functional indexes of the digital up-converter can be well tested and whether the indexes meet the design requirements is judged, so that the performance of the satellite mobile communication terminal digital up-converter is ensured.

The invention relates to an automatic detection and application method of optical port transmission rate, which can realize two types of selective transmission of optical rate and comprises the steps of: 1, in a downlink, transmitting 1.25Gbps data according to 2.5Gbps, and converting the 1.25Gbps data into two paths of data with parallel high-low levels through a DDR (Double Data Rate) module; judging optical port transmission rates and then generating corresponding indicating signals; and respectively selecting all carriers as required from a plurality of antenna carriers for the two types of optical port transmission rates, and transmitting to a DUC (Digital Up Converter) module for transmitting out of a base band; and (2) in an uplink, inserting a plurality of carriers into corresponding antenna carriers according to the indicating signals; and then dividing the 1.25Gbps data into two same high-low level data, transmitting the data out of the base band through the DDR module to combine the data into a string and converting a processing chip. The invention is beneficial to reducing research and development cost and maintenance cost in a large scale, and adaptively detects the optical transmission rate through software without excessive manual intervention.

A transmitter includes a first digital up-converter for converting data to an intermediate frequency (IF) signal, a pulse width modulator (PWM) for encoding the IF signal to an IF pulse train, a second digital up-converter for converting the IF pulse train to a radio frequency (RF) pulse train, a power amplifier for amplifying the RF pulse train; and a filter for reconstructing a RF analog signal from the amplified RF pulse train.

A signal intermediate frequency transmitting device of a multimode mobile communication system comprises a parameter automatic configuration module, an interpolation filter module, a digital up-converter module and a D / A converter. The parameter automatic configuration module is used for generating frequency points needed by the digital up-converter module and filter coefficients and the interpolation rate needed by the interpolation filer module according to different communication systems; the interpolation filter module is used for conducting interpolation and filter according to the filter coefficients and the interpolation rate; the digital up-converter module is used for up converting signals output by the interpolation filter module to the frequency points and outputting the signals to the D / A converter; the D / A converter is used for conducting digital-to-analogue conversion on the signals output by the digital up-converter module. The signal intermediate frequency transmitting device is suitable for LTE-CDMA / WCDMA / TD-SCDMA / GSM communication systems. The interpolation filter module comprises a four-level filter. The digital up-converter module comprises a digital frequency mixer. The signal intermediate frequency transmitting device can support the multiple communication systems, the structure of the system is simplified, the size of the device is small, and the device is low in manufacturing cost.

The method includes steps: obtaining coefficient of temperature compensation from ambient temperature and empirical value; using the coefficient to control amplitude of baseband signal, and further to control emission power of system. The equipment includes module of temperature collection and processor, module for processing code element in baseband, digital up converter, and D / A converter. The invention implements power control at base band, providing high precision for temperature compensation of power. Moreover, the invention removes complicated compensation circuit in radio frequency so as to simplify system and reduce cost. Features are: easy controlled flexible adjustment of step size, reduced interference between systems, raised system capacity etc.

The invention discloses a PA (power amplifier) overpower protecting method and a PA overpower protecting device, which is used for realizing the more complete overpower protection of a PA. The method comprises the following steps that the existing statistical energy protection mechanism is adopted; by aiming at in-phase component and orthogonal component data of phase and amplitude signals of each antennas subjected to DUC (digital up converter), CFR (crest ractor reduction) and DPD (digital pre distortion) processing, the sum of the energy value of the orthogonal component data and the energy value of the in-phase component of phase and amplitude signals in each second time duration is respectively calculated, and the second sum value is obtained; and the second sum value is compared with the preset second power protection threshold value, and when the second sum value of any one antenna is greater than the second power protection threshold value, the in-phase component and orthogonal component data of the phase and amplitude signals in each second time duration is sent to the PA after zero clearing, wherein the second time duration is smaller than 1 chip, so the more complete overpower protection of the PA is realized.

The invention provides a baseband signal processing platform based on software radio. The baseband signal processing platform includes a digital signal processor, a field-programmable gate array connected with the digital signal processor, and an intermediate frequency interface module connected with the field-programmable gate array. The intermediate frequency interface module comprises a digital up-converter and a digital down-converter. The digital signal processor is used for coding and modulating or demodulating and decoding a digital baseband signal. The field-programmable gate array is used for logic programming of the coded and modulated or demodulated and decoded digital baseband signal. The digital up-converter is used for converting the digital baseband signal after logic programming into an intermediate frequency analog signal. The digital down-converter is used for receiving and converting the intermediate frequency analog signal into a digital baseband signal. With the invention, various wireless communication functions can be achieved by loading the software, and in this way, the baseband signal processing platform can have high versatility, a flexible structure, and strong software upgradable and reconfigurable capacities.

The invention discloses a digital up converter capable of performing resampling of random multiples. The digital up converter is used for receiving i and q paths of baseband signals, performing digital up conversion on the two paths of baseband signals and outputting an intermediate frequency signal obtained after processing to a DAC, the digital up converter comprises a forming filter, a resampling module and a frequency mixing module, wherein the resampling module performs resampling on the base bands i and q, can realize up sampling rate conversion of random multiples and can flexibly change the sampling rates of the baseband signals, the adaptability of the sampling rate of the intermediate frequency signal obtained by the frequency mixing module by performing i / q adjustment on the i and q paths of baseband signals is high, which is beneficial for the selection and calibration of the sampling rate of the DAC, moreover the digital up converter does not need to use a CIC filter, a half band filter or a CIC compensation filter, therefore the structure is simple, and the implementation hardware and software is facilitated.