CN102098005A

CN102098005A - Digital down converter and digital upconverter

Info

Publication number: CN102098005A
Application number: CN2010105996006A
Authority: CN
Inventors: 李兴斌; 汤国东; 赵卫杰; 杨建华; 李爱红
Original assignee: New Postcom Equipment Co Ltd
Current assignee: Beijing Haiyun Technology Co. Ltd.
Priority date: 2010-12-13
Filing date: 2010-12-13
Publication date: 2011-06-15
Anticipated expiration: 2030-12-13
Also published as: CN102098005B

Abstract

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.

Description

Digital down converter and digital up converter

Technical field

The present invention relates to converter technique, particularly a kind of digital down converter and digital up converter.

Background technology

Digital Down Convert (Digital Down Convert, DDC) and Digital Up Convert (Digital Up Convert DUC) is the important component part of digital intermediate frequency design.DDC will drop on the base band frequency after extraction of intermediate-freuqncy signal process and the filtering; DUC becomes baseband signal into IF-FRE through behind the interpolation filtering.Existing DDC and DUC based on FPGA, mainly comprise digital filter, digital mixer and digital controlled oscillator (Numerical Control Oscillator, NCO).

Fig. 1 is the structural representation of existing digital down converter.Now in conjunction with Fig. 1, the structure of existing digital down converter is described, specific as follows:

Existing digital down converter comprises A/D converter 10, decimation filter 11, first digital mixer 12, second digital mixer 13, digital controlled oscillator 14, first low pass filter 15 and second low pass filter 16.Wherein, A/D converter 10 is sampled to the analog if signal that receives according to the sample rate of outside input, obtains digital medium-frequency signal, and the output digital medium-frequency signal is to decimation filter 11; 11 pairs of digital medium-frequency signals that receive of decimation filter carry out decimation in frequency, to reduce data transmission rate (being also referred to as data transfer rate), digital medium-frequency signal to the first digital mixer 12 and second digital mixer 13 after output is extracted; Digital controlled oscillator 14 produces local quadrature carrier signal by look-up table, output orthogonal carrier signal to the first digital mixer 12 and second digital mixer 13; First digital mixer 12 carries out the I road that the quadrature mixing obtains baseband signal to the received signal, I road to the first low pass filter 15 of output baseband signal; Second digital mixer 13 carries out the Q road that the quadrature mixing obtains baseband signal to the received signal, Q road to the second low pass filter 16 of output baseband signal; The I road of 15 pairs of baseband signals of first low pass filter carries out exporting behind the shaping filter; The Q road of 16 pairs of baseband signals of second low pass filter carries out exporting behind the shaping filter.

As shown in Figure 1, existing digital down converter only can carry out Digital Down Convert to a carrier signal in the passage to be handled, and in the Digital Down Convert processing procedure, need two digital mixers to this carrier signal carry out the quadrature mixing, two filters carry out filtering to the I road and the Q road of baseband signal respectively, and need to spend bigger look-up table resource among the existing NCO that utilizes look-up table.When adopting existing digital down converter that multi-carrier signal is carried out Digital Down Convert,, need the employing and the digital down converter of the number of carrier signal to handle in order to improve signal processing efficiency.In order to control a plurality of digital down converters, not only need complicated control signal, and expended more logical resource, improved the complexity of design.

Fig. 2 is the structural representation of existing digital up converter.Now in conjunction with Fig. 2, the structure of existing digital up converter is described, specific as follows:

Existing digital up converter comprises first interpolation filter 20, second interpolation filter 21, the 3rd interpolation filter 22, the 4th interpolation filter 23, first digital mixer 24, second digital mixer 25, digital controlled oscillator 26, complex mixer 27 and digital to analog converter 28.Wherein, the I road of 20 pairs of baseband signals that receive of first interpolation filter is carried out the zero insertion Value Operations and is exported in the 3rd interpolation filter 22; The Q road of 21 pairs of baseband signals that receive of second interpolation filter is carried out the zero insertion Value Operations and is exported in the 4th interpolation filter 23; N times of interpolation filtering carried out on the I road of 22 pairs of baseband signals that receive of the 3rd interpolation filter, so that the signal behind N times of interpolation filtering is consistent with the quadrature carrier signals sampling rate of digital controlled oscillator 26 outputs; N times of interpolation filtering carried out on the Q road of 23 pairs of baseband signals that receive of the 4th interpolation filter, so that the signal behind N times of interpolation filtering is consistent with the quadrature carrier signals sampling rate of digital controlled oscillator 26 outputs; Digital controlled oscillator 26 output orthogonal carrier signal to the first digital mixers 24 and second digital mixer 25; First digital mixer 24 carries out mixing to the received signal, obtains the I road of intermediate-freuqncy signal; Second digital mixer 25 carries out mixing to the received signal, obtains the Q road of intermediate-freuqncy signal; Mix on the I road and the Q road of 27 pairs of intermediate-freuqncy signals that receive of complex mixer, obtains complex intermediate frequency signal, and export digital to analog converter 28 to; Digital to analog converter 28 is converted to analog signal and output with the digital signal of the complex intermediate frequency signal that receives.

As shown in Figure 2, also there is the defective of digital down converter shown in Figure 1 in existing digital up converter, promptly when multi-carrier signal is carried out upconversion process need with the digital up converter of carrier signal number, in order to control a plurality of digital up converter, not only need complicated control signal, and expended more logical resource, improved the complexity of design.

In sum, existing digital up converter and digital down converter are carrying out in the conversion process multi-carrier signal, not only need complicated control signal, and have expended more logical resource; For the digital up converter and the digital down converter that adopt special chip, though control easily, its most of function has cured, and compatibility and flexibility are relatively poor.

Summary of the invention

In view of this, goal of the invention of the present invention is to provide a kind of digital down converter, and this digital down converter can be saved resource when improving easily control property.

Goal of the invention of the present invention is to provide a kind of digital up converter, and this digital up converter can be saved resource when improving easily control property.

For achieving the above object, technical scheme of the present invention specifically is achieved in that

A kind of digital down converter, comprise the intermediate-freuqncy signal analog to digital converter of sampling that is used for input, described digital down converter also comprises: first order frequency mixing module, the first parameter control module, the many rate conversion module of the many rate conversion module of the first order and the second level;

Described first order frequency mixing module produces first orthogonal local oscillation signal according to the sample rate of the described analog to digital converter of first parameter control module output; The intermediate-freuqncy signal of described first order frequency mixing module after with the sampling of first orthogonal local oscillation signal and described analog to digital converter output carried out mixing, exports I/Q two-way mixed frequency signal to the many rate conversion module of the described first order in the multiplexing mode of 2 carrier time-divisions; The data transfer rate of arbitrary road signal equals the sample rate of described analog to digital converter in the described I/Q two-way mixed frequency signal, and smaller or equal to the clock frequency of described first order frequency mixing module;

The many rate conversion module of the described first order are adjusted into data transfer rate sum more than or equal to I/Q two-way mixed frequency signal with the clock frequency of this module; Carrier multiplexing according to the output of the first parameter control module is counted n, adopt the multiplexing mode of 2 carrier time-divisions respectively the data transfer rate of each road signal in the I/Q two-way mixed frequency signal to be carried out n/2 and doubly extract and filtering, the data transfer rate of each road signal of I/Q two-way mixed frequency signal is reduced to the 1/n of the clock frequency of the many rate conversion module of the first order; The many rate conversion module of the described first order are carried out mixing with second orthogonal local oscillation signal of its generation with the signal that receives, n carrier wave carried out carrier wave to be moved, in the multiplexing mode of n carrier time-division I road signal and Q road signal are carried out 2 times and extract and filtering, and the I road signal after will extracting and Q road signal export the many rate conversion module in the described second level to; Described n is an even number;

The many rate conversion module in the described second level are counted n according to the carrier multiplexing of first parameter control module output, and the clock frequency of this module is adjusted into more than or equal to the data transfer rate of the arbitrary road signal that receives and the product that carrier multiplexing is counted n; Count the frequency of n and baseband signal according to the carrier multiplexing of first parameter control module output, adopt the multiplexing mode of n carrier time-division that the data transfer rate of each road signal of receiving is carried out n and doubly extract and filtering the I road and the Q road of output baseband signal.

In the above-mentioned low-converter, described first order frequency mixing module comprises:

First digital controlled oscillator, the sample rate according to the described analog to digital converter of first parameter control module output produces first orthogonal local oscillation signal, exports first orthogonal local oscillation signal to the first digital mixer;

First digital mixer carries out mixing with the intermediate-freuqncy signal after the sampling of first orthogonal local oscillation signal and the output of described analog to digital converter, exports I/Q two-way mixed frequency signal to the many rate conversion module of the described first order in the multiplexing mode of 2 carrier time-divisions;

The sample rate that the frequency of described first orthogonal local oscillation signal equals described analog to digital converter deducts the frequency of described intermediate-freuqncy signal.

In the above-mentioned low-converter, the many rate conversion module of the described first order comprise:

First order first-in first-out unit, according to the data transfer rate that receives I/Q two-way mixed frequency signal, the clock frequency of the many rate conversion module of the described first order is adjusted into data transfer rate sum more than or equal to I/Q two-way mixed frequency signal, exports I/Q two-way mixed frequency signal to many times of extracting units of the first order in the multiplexing mode of 2 carrier time-divisions;

Many times of extracting units of the first order, carrier multiplexing according to the output of the first parameter control module is counted n, adopting the multiplexing mode of 2 carrier time-divisions respectively the data transfer rate of each the road signal in the I/Q two-way mixed frequency signal to be carried out n/2 doubly extracts and filtering, the data transfer rate of each road signal of I/Q two-way mixed frequency signal is reduced to the 1/n of the clock frequency of the many rate conversion module of the first order, adopt the multiplexing mode of 2 carrier time-divisions to export the plural mixing of signal to the first unit after the I/Q two-way extracts;

The first plural mixing unit, count n according to the carrier multiplexing of first parameter control module output and produce second orthogonal local oscillation signal, signal after described second orthogonal local oscillation signal and the extraction that receives is carried out mixing, n carrier wave carried out carrier wave to be moved, export I road signal to first order half-band filter in the multiplexing mode of n carrier time-division, export Q road signal to second level half-band filter in the multiplexing mode of n carrier time-division; The frequency of described second orthogonal local oscillation signal is directly proportional with the merchant of signal(-) carrier frequency that receives and sample rate;

First order half-band filter carries out 2 times to the data transfer rate of the I road signal that receives and extracts and filtering, and exports 2 times of I road signals after the extraction to the many rate conversion module in the described second level in the multiplexing mode of n carrier time-division;

Second level half-band filter carries out 2 times to the data transfer rate of the Q road signal that receives and extracts and filtering, and exports 2 times of Q road signals after the extraction to the many rate conversion module in the described second level in the multiplexing mode of n carrier time-division.

In the above-mentioned low-converter, the many rate conversion module in the described second level comprise:

First-in first-out unit, the second level, according to the data transfer rate of the I road signal after the data transfer rate of the Q road signal after 2 times of extractions that receive and the 2 times of extractions, the clock frequency of the many rate conversion module in the described second level is adjusted into more than or equal to the data transfer rate of the arbitrary road signal that receives and the product that carrier multiplexing is counted n; With the multiplexing mode of n carrier time-division export I road signal to the second level many times of extracting units; Export Q road signal to many times of extracting units of the third level in the multiplexing mode of n carrier time-division;

The many times of extracting units in the second level are counted the frequency of n and baseband signal according to the carrier multiplexing of first parameter control module output, adopt the multiplexing mode of n carrier time-division that the I road signal that receives is carried out n and doubly extract and filtering, the I road of output baseband signal;

Many times of extracting units of the third level are counted the frequency of n and baseband signal according to the carrier multiplexing of first parameter control module output, adopt the multiplexing mode of n carrier time-division that the Q road signal that receives is carried out n and doubly extract and filtering, the Q road of output baseband signal.

In the above-mentioned low-converter, it is 12 that described carrier multiplexing is counted n;

Many times of extracting units of the described first order comprise first half-band filter and a FIR filter; Described first half-band filter, one end connects described first order first-in first-out unit, and the other end connects a described FIR filter, is used for 2 times and extracts and filtering; A described FIR filter other end connects the described first plural mixing unit, is used for 3 times and extracts and filtering;

Described first order half-band filter and described second level half-band filter are the half-band filter that is used for 2 times of extractions and filtering.

In the above-mentioned low-converter, it is 12 that described carrier multiplexing is counted n; The many times of extracting units in the described second level comprise the 2nd FIR filter, the 4th half-band filter and the first radical sign raised cosine filter; Many times of extracting units of the described third level comprise the 3rd FIR filter, the 5th half-band filter and the second radical sign raised cosine filter;

Described the 2nd FIR filter one end is connected in first-in first-out unit, the described second level, and the other end connects described the 4th half-band filter, is used for 3 times and extracts and filtering; Described the 4th half-band filter other end connects the described first radical sign raised cosine filter, is used for 2 times and extracts and filtering; The described first radical sign raised cosine filter is used for shaping filter and 2 times of extractions;

Described the 3rd FIR filter one end is connected in first-in first-out unit, the described second level, and the other end connects described the 5th half-band filter, is used for 3 times and extracts and filtering; Described the 5th half-band filter other end connects the described second radical sign raised cosine filter, is used for 2 times and extracts and filtering; The described second radical sign raised cosine filter is used for shaping filter and 2 times of extractions.

A kind of digital up converter, comprise in order to digital signal is converted to the digital to analog converter of analog signal, it is characterized in that described digital up converter also comprises: the second parameter control module, the many rate conversion module of the third level, the many rate conversion module of the fourth stage, second level frequency mixing module and the many rate conversion module of level V;

The many rate conversion module of the described third level are adjusted into the clock frequency of described digital up converter more than or equal to the I road of the baseband signal that receives and the clock frequency sum of Q road signal; The I road of adjusting the baseband signal of transmitting in the multiplexing mode of n carrier time-division after the clock frequency and the data transfer rate of Q road signal are carried out n/2 times of interpolation and filtering respectively, export I road signal after the interpolation and Q road signal respectively to the many rate conversion module of the described fourth stage in the multiplexing mode of n carrier time-division; The I road of the described baseband signal that receives and Q road signal transmit in the multiplexing mode of n carrier time-division respectively; Described n is an even number;

The many rate conversion module of the described fourth stage are counted n according to the carrier multiplexing of second parameter control module output, in the mode that the n carrier time-division is multiplexing I road signal and the Q road signal that receives carried out interpolation and filtering, obtaining data transfer rate is the I road signal of a and the Q road signal that data transfer rate is a; Respectively I road signal and Q road signal are carried out interpolation and filtering in the mode that the n/2 carrier time-division is multiplexing, obtaining data transfer rate is the I road signal of b and the Q road signal that data transfer rate is b, and exports I road signal and Q road signal to described second level frequency mixing module in the multiplexing mode of n/2 carrier time-division; Described a equals the clock frequency of described digital up converter and counts n divided by carrier multiplexing; Described b is 2 times of a;

Described second level frequency mixing module is counted n according to the carrier multiplexing of second parameter control module output, to receiving carrier wave stack and the mixing that the I road signal that transmits in the multiplexing mode of n/2 carrier time-division and Q road signal carry out the n carrier signal respectively, export I/Q two-way mixed frequency signal to the many rate conversion module of described level V in the multiplexing mode of 2 carrier time-divisions;

The many rate conversion module of described level V are according to the frequency of the intermediate-freuqncy signal of second parameter control module output, the I/Q two-way mixed frequency signal that receives is carried out c times of interpolation and filtering, and the I/Q two-way mixed frequency signal of exporting intermediate-freuqncy signal in the multiplexing mode of 2 carrier time-divisions is to described digital to analog converter; Described c equals the data transfer rate of the frequency of intermediate-freuqncy signal divided by arbitrary road signal in the described I/Q two-way mixed frequency signal that receives.

Preferably, also comprise a third level first-in first-out unit between many rate conversion module of described level V and the described digital to analog converter;

Described third level first-in first-out unit is adjusted the clock frequency of I/Q two-way mixed frequency signal according to the clock frequency of the described digital to analog converter of second parameter control module output, exports adjusted I/Q two-way mixed frequency signal to described digital to analog converter.

In the above-mentioned upconverter, the many rate conversion module of the described third level comprise:

Fourth stage first-in first-out unit, according to the clock frequency of the Q road signal of the I road signal of the baseband signal that receives and baseband signal, the clock frequency of described digital up converter is adjusted into clock frequency sum more than or equal to the Q road signal of the clock frequency of the I road signal of the baseband signal that receives and baseband signal; Many times of interpolation units in Q road to the second level of baseband signal are exported to many times of interpolation units of the first order in the I road of exporting baseband signal in the multiplexing mode of n carrier time-division in the multiplexing mode of n carrier time-division;

Many times of interpolation units of the first order are counted n according to the carrier multiplexing of second parameter control module output, and n/2 times of interpolation and filtering are carried out in the I road of butt joint As-received band signal, export I road signal to the many rate conversion module of the described fourth stage in the multiplexing mode of n carrier time-division;

The many times of interpolation units in the second level, carrier multiplexing according to the output of the second parameter control module is counted n, n/2 times of interpolation and filtering are carried out in Q road to the baseband signal that receives, export Q road signal to the many rate conversion module of the described fourth stage in the multiplexing mode of n carrier time-division.

In the above-mentioned upconverter, the many rate conversion module of the described fourth stage comprise:

Many times of interpolation units of the third level, carrier multiplexing according to the output of the second parameter control module is counted n, in the mode that the n carrier time-division is multiplexing the I road signal that receives being carried out d times of interpolation and filtering, is that the I road signal of a is to many times of interpolation units of level V with the multiplexing mode output data rate of n carrier time-division; Described d equals the merchant that the data transfer rate of the described I road signal that receives and product that carrier multiplexing is counted n obtain divided by the clock frequency of described digital up converter;

Many times of interpolation units of the fourth stage, carrier multiplexing according to the output of the second parameter control module is counted n, in the mode that the n carrier time-division is multiplexing the Q road signal that receives being carried out d times of interpolation and filtering, is six grades of many times of interpolation units of Q road signal to the of a with the multiplexing mode output data rate of n carrier time-division;

Many times of interpolation units of level V, carrier multiplexing according to the output of the second parameter control module is counted n, is that the I road signal of a carries out 2 times of interpolations and filtering in the multiplexing mode of n/2 carrier time-division to the data transfer rate that receives, obtaining data transfer rate is the I road signal of b, and exports I road signal to described second level frequency mixing module in the multiplexing mode of n/2 carrier time-division;

The 6th grade of many times of interpolation units, carrier multiplexing according to the output of the second parameter control module is counted n, is that the Q road signal of a carries out 2 times of interpolations and filtering in the multiplexing mode of n/2 carrier time-division to the data transfer rate that receives, obtaining data transfer rate is the I road signal of b, and exports Q road signal to described second level frequency mixing module in the multiplexing mode of n/2 carrier time-division.

In the above-mentioned upconverter, described second level frequency mixing module comprises:

Second digital controlled oscillator is counted n and the data transfer rate of the signal that receives according to the carrier multiplexing of second parameter control module output, produces the 3rd orthogonal local oscillation signal and exports second digital mixer to; The frequency of described the 3rd orthogonal local oscillation signal is directly proportional with the merchant of signal frequency that receives and sample rate;

Second digital mixer, the 3rd orthogonal local oscillation signal of counting n and receiving according to the carrier multiplexing of second parameter control module output, with the carrier wave stack that the time-multiplexed mode of n/2 is carried out the n carrier wave respectively to the I road signal that receives and Q road signal, I road signal and Q road signal to the second complex mixer after the outgoing carrier stack;

Second complex mixer is carried out plural mixing with I road signal and Q road signal after the carrier wave stack, exports I/Q two-way mixed frequency signal to the many rate conversion module of described level V with 2 carrier time-division multiplex modes.

In the above-mentioned upconverter, the many rate conversion module of described level V comprise one the 7th grade of many times of interpolation unit;

Described the 7th grade of many times of interpolation units are according to the frequency of the intermediate-freuqncy signal of second parameter control module output, the I/Q two-way mixed frequency signal that receives is carried out c times of interpolation and filtering, and the I/Q two-way mixed frequency signal of exporting intermediate-freuqncy signal in the multiplexing mode of 2 carrier time-divisions is to described digital to analog converter.

Preferably, the many rate conversion module of the described fourth stage also comprise:

First gain adjusting unit, connect many times of interpolation units of described level V and described second level frequency mixing module, range value according to the intermediate-freuqncy signal of described second parameter control module output, I road signal to many times of interpolation unit outputs of described level V carries out the signal amplitude adjustment, exports adjusted I road signal to described second level frequency mixing module in the time-multiplexed mode of n/2;

Second gain adjusting unit, connect described the 6th grade of many times of interpolation units and described second level frequency mixing module, range value according to the intermediate-freuqncy signal of described second parameter control module output, Q road signal to described the 6th grade of many times of interpolation unit output carries out the signal amplitude adjustment, exports adjusted Q road signal to described second level frequency mixing module in the time-multiplexed mode of n/2.

In the above-mentioned upconverter, described n is 12; Many times of interpolation units of the described first order comprise the 3rd radical sign raised cosine filter and the 4th FIR filter; The many times of interpolation units in the described second level comprise the 4th radical sign raised cosine filter and the 5th FIR filter;

Described the 3rd radical sign raised cosine filter one end connects described fourth stage first-in first-out unit, and the other end connects described the 4th FIR filter, is used for 2 times of interpolations and filtering; Described the 4th FIR filter other end connects many times of interpolation units of the described third level, is used for 3 times of interpolations and filtering;

Described the 4th radical sign raised cosine filter one end connects described fourth stage first-in first-out unit, and the other end connects described the 5th FIR filter, is used for 2 times of interpolations and filtering; Described the 5th FIR filter other end connects many times of interpolation units of the described fourth stage, is used for 3 times of interpolations and filtering.

In the above-mentioned upconverter, many times of interpolation units of the described third level are one to be used for the FIR filter of 3 times of interpolations and filtering;

Many times of interpolation units of described level V are one to be used for the half-band filter of 2 times of interpolations and filtering;

Many times of interpolation units of the described fourth stage are one to be used for the FIR filter of 3 times of interpolations and filtering;

Described the 6th grade of many times of interpolation units are one to be used for the half-band filter of 2 times of interpolations and filtering.

Above-mentioned technical scheme as seen, in the digital down converter provided by the invention, after first order frequency mixing module is carried out the I road and Q road of mixing acquisition intermediate-freuqncy signal with intermediate-freuqncy signal, export I/Q two-way mixed frequency signal to the many rate conversion module of the first order in the multiplexing mode of 2 carrier time-divisions, the many rate conversion module of the many rate conversion module of the first order and the second level are before extracting, earlier clock frequency is carried out synchronously, adopt the multiplexing mode of carrier time division to carry out many times of extractions and filtering to the received signal according to the clock frequency synchronously, in the complexity that reduces control signal, saved a large amount of logical resources.In the digital up converter provided by the invention, the many rate conversion module of the third level before carrying out the frequency interpolation advanced row clock frequency synchronously, after the synchronised clock frequency, the many rate conversion module of the many rate conversion module of the third level, the many rate conversion module of the fourth stage, second level frequency mixing module and level V are according to clock frequency after synchronous and the signal data rate that receives, adopt the multiplexing mode of carrier time division to carry out frequency interpolation and filtering to the received signal, in the complexity that reduces control signal, saved a large amount of logical resources.

Description of drawings

Fig. 1 is the structural representation of existing digital down converter.

Fig. 2 is the structural representation of existing digital up converter.

Fig. 3 is the structural representation of digital down converter of the present invention.

Fig. 4 is the structural representation of digital down converter one embodiment of the present invention.

Fig. 5 is the structural representation of digital up converter of the present invention.

Fig. 6 is the structural representation of digital up converter one embodiment of the present invention.

Embodiment

For make purpose of the present invention, technical scheme, and advantage clearer, below with reference to the accompanying drawing embodiment that develops simultaneously, the present invention is described in more detail.

In digital down converter provided by the invention and the digital up converter, frequency converter is confined to that no longer a carrier signal in a certain passage is carried out digital frequency conversion and handles, but adopt the multiplexing mode of carrier time division, utilize the frequency converter among the present invention that a plurality of carrier signals are handled, not only reduce the logical resource that takies, and reduced the complexity of hardware cost and control signal.

In digital down converter of the present invention and the digital up converter, each module and components and parts carry out work under specific clock frequency; The big I of the clock frequency of each module and components and parts is referring to following explanation.

Fig. 3 is the structural representation of digital down converter of the present invention.Now in conjunction with Fig. 3, the structure of digital down converter of the present invention is described, specific as follows:

Digital down converter of the present invention comprises modulus value transducer 30, first order frequency mixing module 31, the many rate conversion module 32 of the first order, the many rate conversion module 33 in the second level and the first parameter control module 34.

Analog to digital converter 30 is used for the intermediate-freuqncy signal that receives is sampled.The sample rate of analog to digital converter 30 has determined the clock frequency of first order frequency mixing module 31.

The first parameter control module 34 exports first order frequency mixing module 31 in order to the sample rate with analog to digital converter 30, carrier multiplexing is counted n export the many rate conversion module 33 of the many rate conversion module 32 of the first order and the second level to, export the frequency of baseband signal to the second level many rate conversion module 33.

First order frequency mixing module 31 produces first orthogonal local oscillation signal according to the sample rate of analog to digital converter 30; The intermediate-freuqncy signal of first order frequency mixing module 31 after with the sampling of first orthogonal local oscillation signal and analog to digital converter 30 outputs carried out mixing, exports I/Q two-way mixed frequency signal to the many rate conversion module 32 of the first order in the multiplexing mode of 2 carrier time-divisions.The frequency of first orthogonal local oscillation signal is the difference of the frequency of the sample rate of analog to digital converter 30 intermediate-freuqncy signal that deducts input.I/Q two-way mixed frequency signal is I road mixed frequency signal and Q road mixed frequency signal, and the data transfer rate of arbitrary road mixed frequency signal equals the sample rate of analog to digital converter 30, and smaller or equal to the clock frequency of first order frequency mixing module 31; Preferably, the data transfer rate of arbitrary road mixed frequency signal equals the clock frequency of first order frequency mixing module 31 in the I/Q two-way mixed frequency signal.Described output in the multiplexing mode of 2 carrier time-divisions is specially: adopt time-multiplexed mode, export 2 carrier waves constantly in difference, one of 2 carrier waves are I road mixed frequency signal, and another carrier wave is a Q road mixed frequency signal.

The many rate conversion module 32 of the first order are adjusted into data transfer rate sum more than or equal to I/Q two-way mixed frequency signal with the clock frequency of this module; Carrier multiplexing according to 34 outputs of the first parameter control module is counted n, adopt the multiplexing mode of 2 carrier time-divisions respectively the data transfer rate of each road signal in the I/Q two-way mixed frequency signal to be carried out n/2 and doubly extract and filtering, the data transfer rate of each road signal of I/Q two-way mixed frequency signal is reduced to the 1/n of the clock frequency of the many rate conversion module 32 of the first order.The many rate conversion module 32 of the first order with second orthogonal local oscillation signal of its generation with extract after signal carry out mixing and the n carrier wave is moved, respectively I road signal and Q road signal are carried out 2 times in the multiplexing mode of n carrier time-division and extract and filtering, and the I road signal after will extracting and Q road signal export the many rate conversion module 33 in the second level respectively to.It is even number that described carrier multiplexing is counted n; The frequency of second orthogonal local oscillation signal is that the merchant of incoming carrier frequency and sample rate be multiply by 32 powers of 2 again; The n carrier wave of the many rate conversion module 32 of the first order is moved for the n carrier wave is moved same frequency range, so that adopt the multiplexing mode output signal of n carrier time-division.Preferably, the data transfer rate sum of the clock frequency of the many rate conversion module 32 of the first order I/Q two-way mixed frequency signal that equals to receive.Describedly I road signal is extracted and filtering, be specially, adopt time-multiplexed mode, n the carrier wave that I road signal comprises extracted and filtering in different time points in the multiplexing mode of n carrier time-division; Describedly Q road signal is extracted and filtering, be specially, adopt time-multiplexed mode, n the carrier wave that Q road signal comprises extracted and filtering in different time points in the multiplexing mode of n carrier time-division.

The many rate conversion module 33 in the second level are counted n according to the carrier multiplexing of the first parameter control module 34 output, and the clock frequency of this module is adjusted into more than or equal to the data transfer rate of the arbitrary road signal that receives and the product that carrier multiplexing is counted n; Count the frequency of n and baseband signal according to the carrier multiplexing of the first parameter control module 34 output, adopt the multiplexing mode of n carrier time-division, the data transfer rate of the I road signal that receives and Q road signal is carried out n doubly extract and filtering the I road and the Q road of output baseband signal.Preferable, the many rate conversion module 33 in the second level are adjusted into data transfer rate that equals its arbitrary road signal that receives and the product that carrier multiplexing is counted n with the clock frequency of this module.

Wherein, first order frequency mixing module 31 comprises first digital mixer 311 and first digital controlled oscillator 312.

First digital controlled oscillator 312 produces first orthogonal local oscillation signal according to the sample rate of the analog to digital converter 30 of the first parameter control module, 34 outputs, exports first orthogonal local oscillation signal to the first digital mixer 311.First digital controlled oscillator 312 of the present invention no longer adopts the mode of look-up table to produce orthogonal local oscillation signal, but produce first orthogonal local oscillation signal according to signals sampling rate that receives and clock frequency, intermediate-freuqncy signal for a certain frequency, the frequency of first orthogonal local oscillation signal is changeless, has greatly saved logical resource.

The intermediate-freuqncy signal of first digital mixer 311 after with the sampling of first orthogonal local oscillation signal and analog to digital converter 30 outputs carried out mixing, obtains the I road and the Q road of intermediate-freuqncy signal; First digital mixer 311 is exported I/Q two-way mixed frequency signal to the many rate conversion module 32 of the first order in the multiplexing mode of 2 carrier time-divisions.First digital mixer 311 adopts time-multiplexed mode to carry out mixing, compares with existing digital down converter, has reduced the use of digital mixer, has saved multiplication resources.

Wherein, the many rate conversion module 32 of the first order comprise first order first-in first-out unit 321, many times of extracting units of the first order 322, first plural mixing unit 323, first order half-band filter 324 and second level half-band filter 325.

First order first-in first-out unit 321 is according to the data transfer rate of each road signal in the I/Q two-way mixed frequency signal, the clock frequency of the many rate conversion module 32 of the first order is adjusted into data transfer rate sum more than or equal to I/Q two-way mixed frequency signal, exports I/Q two-way mixed frequency signal to many times of extracting units of the first order 322 in the multiplexing mode of 2 carrier time-divisions.First order first-in first-out unit 321 is used for data being changed clock zone and isolating, and clock frequency is carried out synchronously, saves the clock resource.Why digital down converter of the present invention can adopt the multiplexing mode of multicarrier to handle, key is digital down converter when carrying out decimation in frequency and filtering, and the clock frequency of element of carrying out decimation in frequency and filtering is more than or equal to the product of carrier multiplexing number and data transfer rate.

Many times of extracting units of the first order 322 are counted n according to the carrier multiplexing of the first parameter control module, 34 outputs, adopting the multiplexing mode of 2 carrier time-divisions that the data transfer rate of each road signal in the I/Q two-way mixed frequency signal is carried out n/2 doubly extracts and filtering, the data transfer rate of each road signal in the I/Q two-way mixed frequency signal is reduced to the 1/n of the clock frequency of the many rate conversion module 32 of the first order, adopt the multiplexing mode of 2 carrier time-divisions to export the plural mixing of signal to the first unit 323 after the I/Q two-way extracts.Signal after described I/Q two-way extracts is signal and Q road the signal extract after of I road after extracting.When many times of extracting units of the first order 322 carried out decimation in frequency and filtering to the received signal, the multiple of its extraction was relevant with the clock frequency that the carrier multiplexing of the first parameter control module, 34 outputs is counted n and this module.

The first plural mixing unit 323 is counted n according to the carrier multiplexing of the first parameter control module, 34 outputs and is produced second orthogonal local oscillation signal, signal after second orthogonal local oscillation signal extracted with the I/Q two-way that receives respectively carries out mixing and the n carrier wave is moved, export I road signal to first order half-band filter 324 in the multiplexing mode of n carrier time-division, export Q road signal to second level half-band filter 325 in the multiplexing mode of n carrier time-division.The first plural mixing unit 323 can comprise the digital controlled oscillator that a digital mixer and that carries out mixing in the multiplexing mode of n carrier time-division is used to produce second orthogonal local oscillation signal; The method that described digital mixer also can adopt existing carrier wave to move is carried out the n carrier wave and is moved, and does not repeat them here.It is exactly to different time points with n carrier separation that described n carrier wave is moved.

The data transfer rate of the I road signal that 324 pairs of first order half-band filters receive carries out 2 times and extracts and filtering, and with the multiplexing mode of n carrier time-division export 2 times of I road signals after the extraction to the second level many rate conversion module 33.When first order half-band filter 324 extracts to the received signal, adopt the multiplexing mode of carrier time division to handle, saved logical resource, reduced hardware cost.

The data transfer rate of the Q road signal that 325 pairs of second level half-band filters receive carries out 2 times and extracts and filtering, and with the multiplexing mode of n carrier time-division export 2 times of Q road signals after the extraction to the second level many rate conversion module 33.When second level half-band filter 325 extracts to the received signal, adopt the multiplexing mode of carrier time division to handle, saved logical resource, reduced hardware cost.

Wherein, the many rate conversion module in the second level comprise first-in first-out unit, the second level 331, the second level many times of extracting units 332 and many times of extracting units of the third level 333.

First-in first-out unit, the second level 331 is according to the data transfer rate of the Q road signal that receives and the data transfer rate of I road signal, and the clock frequency of the many rate conversion module 33 in the second level is adjusted into more than or equal to the data transfer rate of the arbitrary road signal that receives and the product that carrier multiplexing is counted n; The described arbitrary road signal that receives be 2 times after the extraction I road signal or the Q road signal after 2 times of extractions.First-in first-out unit, the second level 331 with the multiplexing mode of n carrier time-division export 2 times of I road signals after the extraction to the second level many times of extracting units 332, export 2 times of Q road signals after the extraction to many times of extracting units of the third level 333 in the multiplexing mode of n carrier time-division.First-in first-out unit, the second level 331 is used for data being changed clock zone and isolating, and clock frequency is carried out synchronously, saves the clock resource.

The carrier multiplexing that many times of extracting units in the second level 332 are exported according to the first parameter control module 34 is counted the frequency of n and baseband signal, adopts the multiplexing mode of n carrier time-division that the I road signal that receives is carried out n and doubly extracts and filtering, the I road of output baseband signal.

The carrier multiplexing that many times of extracting units of the third level 333 are exported according to the first parameter control module 34 is counted the frequency of n and baseband signal, adopts the multiplexing mode of n carrier time-division that the Q road signal that receives is carried out n and doubly extracts and filtering, the Q road of output baseband signal.

Fig. 4 is the structural representation of digital down converter one embodiment of the present invention.As shown in Figure 4, in this embodiment, the carrier multiplexing number is 12.Now in conjunction with Fig. 4, the structure of the digital down converter among this embodiment is described, specific as follows:

The digital down converter of present embodiment comprises analog to digital converter 400, digital mixer 401, digital controlled oscillator 402, the first first-in first-out unit 403, first half-band filter 404, first have limit for length's unit impulse response (Finite Impulse Response, FIR) filter 405, the first plural mixing unit 406, second half-band filter 407, the 3rd half-band filter 408, the second first-in first-out unit 409, the 2nd FIR filter 410, the 3rd FIR filter 411, the 4th half-band filter 412, the 5th half-band filter 413, the first radical sign raised cosine filter 414, the second radical sign raised cosine filter 415 and the first parameter control module 34.

Analog to digital converter 400 is equivalent to the analog to digital converter 30 among Fig. 3, and its sample rate is 184.32MHz; The frequency of the intermediate-freuqncy signal that analog to digital converter 400 receives is 138.24 ± 1.92MHz, and being positioned at second is the Qwest district.

Digital mixer 401 is equivalent to first digital mixer 311 among Fig. 3; Digital controlled oscillator 402 is equivalent to first digital controlled oscillator 312 among Fig. 3.The clock frequency of digital mixer 401 and digital controlled oscillator 402 is 184.32MHZ; In order to simplify the operation, digital down converter for 12 carrier multiplexings, the frequency of the local oscillation signal of digital controlled oscillator 402 outputs is 1/4th of a sample rate, and the numerical value of the data transfer rate of the intermediate-freuqncy signal of exporting after digital mixer 401 mixing is identical with clock frequency, i.e. 184.32Ms/s.

The first first-in first-out unit 403 is equivalent to the first order first-in first-out unit 321 among Fig. 3.Take logical resource in order to realize reducing, the present invention carries out the extraction of multiple frequence rate in the multiplexing mode of 2 carrier time-divisions to the I road and the Q road of intermediate-freuqncy signal; Extract in order in the multiplexing mode of 2 carrier time-divisions the multiple frequence rate to be carried out on the I road of intermediate-freuqncy signal and Q road, the first first-in first-out unit 403 is with the signal Synchronization that the receives clock frequency to 368.64MHz, to isolate.At this moment, I/Q two-way mixed frequency signal is exported in the multiplexing mode of 2 carrier time-divisions in the first first-in first-out unit 403, and the data transfer rate of every road signal is 184.32Ms/s; The frequency sum of I/Q two-way mixed frequency signal is 368.64Ms/s.

First half-band filter 404 and a FIR filter 405 have been formed many times of extracting units of the first order among Fig. 3 322.First half-band filter 404 carries out 2 times according to the parameter of the first parameter control module, 34 outputs and extracts and filtering, and a FIR filter 405 carries out 3 times according to the parameter of the first parameter control module, 34 outputs and extracts and filtering.Adopting the FIR filter after why adopting half-band filter earlier, mainly is to consider that the FIR filter can not extract the signal of higher data and filtering; Why adopt 2 times and 3 times of extractions, mainly be the carrier multiplexing number that adopts according to the digital down converter among this embodiment, so that the data transfer rate of many times of extractions of a FIR filter 405 outputs and filtered signal and product that carrier multiplexing is counted n are smaller or equal to clock frequency.Among this embodiment, each the road signal in first half-band filter 404 and 405 pairs of I/Q two-way of the FIR filter mixed frequency signal adopts time-multiplexed mode to carry out decimation in frequency; The data transfer rate of each road signal is 30.72Ms/s in the I/Q two-way mixed frequency signal of the one FIR filter 405 outputs.

The first plural mixing unit 406 is equivalent to the first plural mixing unit 323 among Fig. 3.The first plural mixing unit 406 has realized that the carrier wave of 12 carrier waves moves, data transfer rate keeps 30.72Ms/s constant, so that the multiplexing mode of following adopted 12 carrier time-divisions is carried out extraction of multiple frequence rate and filtering to I road and Q road signal, reduce taking logical resource, reduce hardware cost.

Second half-band filter 407 is equivalent to first order half-band filter 324, the three half-band filters 408 among Fig. 3 and is equivalent to second level half-band filter 325 among Fig. 3.Second half-band filter 407 adopts the multiplexing mode of 12 carrier time-divisions, the I road signal that receives is carried out 2 times extract and filtering, and data transfer rate is reduced to 15.36Ms/s; The 3rd half-band filter 408 adopts the multiplexing mode of 12 carrier time-divisions, the Q road signal that receives is carried out 2 times extract and filtering, and data transfer rate is reduced to 15.36Ms/s.

The second first-in first-out unit 409 is equivalent to the first-in first-out unit, the second level 331 among Fig. 3.Adding the first-in first-out unit be used to change clock frequency here, is that the signal of 15.36Ms/s further carries out many times and extracts and filtering in order to adopt the multiplexing mode of 12 carrier time-divisions to data transfer rate mainly, to obtain the baseband signal of required frequency.The setting that the second first-in first-out unit 409 is multiplexing according to 12 carrier time-divisions, the clock frequency of element that to carry out many times of extractions and filtering is synchronously to 184.32MHz, not only saved clock resource and logical resource, and be convenient to subsequent element and continue adopt the multiplexing mode of 12 carrier time-divisions to handle.

The 2nd FIR filter 410, the 4th half-band filter 412 and the first radical sign raised cosine filter 414 have been formed many times of extracting units in the second level shown in Figure 3 332; The 3rd FIR filter 411, the 5th half-band filter 413 and the second radical sign raised cosine filter 415 have been formed many times of extracting units of the third level shown in Figure 3 333.In the said elements, the 2nd FIR filter 410 and the 3rd FIR filter 411 carry out 3 times according to the parameter of the first parameter control module, 34 outputs and extract and filtering, the 4th half-band filter 412 and the 5th half-band filter 413 carry out 2 times according to the parameter of the first parameter control module, 34 outputs and extract and filtering, and the first radical sign raised cosine filter 414 and the second radical sign raised cosine filter 415 carry out 2 times according to the parameter of the first parameter control module, 34 outputs and extract and filtering; Determine by the data transfer rate of the signal of required baseband signal and 409 outputs of the second first-in first-out unit about the multiple sum that each filter extracts.

Digital down converter shown in Figure 4 only is to have provided a preferred embodiment adopting 12 carrier time-division multiplex modes to handle; The kind of the filter that comprises in the digital down converter is not limited to above several, and in the foregoing description, the extracting multiple of each filter also only is a preferred values, is not limited to above several.

Fig. 5 is the structural representation of digital up converter of the present invention.Now in conjunction with Fig. 5, the structure of digital up converter of the present invention is described, specific as follows:

Digital up converter of the present invention comprises: the many rate conversion module 50 of the third level, the many rate conversion module 51 of the fourth stage, second level frequency mixing module 52, the many rate conversion module 53 of level V, digital to analog converter 54 and the second parameter control module 55.Digital up converter of the present invention is that the baseband signal of transmitting in the multiplexing mode of n carrier time-division is carried out upconversion process; Preferably, be used for the baseband signal of digital down converter output shown in Figure 3 is carried out upconversion process.

Digital to analog converter 54 is used for digital signal is converted to analog signal.Digital to analog converter 54 can adopt the existing components and parts that digital signal are converted to analog signal that have, and does not repeat them here.

The second parameter control module 55 is used for that carrier multiplexing is counted n and exports the many rate conversion module 50 of the third level, the many rate conversion module 51 of the fourth stage, second level frequency mixing module 52 and the many rate conversion module 53 of level V to; Be used for exporting the frequency of intermediate-freuqncy signal to level V many rate conversion module 53.Described intermediate-freuqncy signal is for carrying out the intermediate-freuqncy signal that expectation obtains after the up-conversion to baseband signal.

The many rate conversion module 50 of the third level are adjusted into clock frequency sum more than or equal to the I road and the Q road of the baseband signal that receives with the clock frequency of digital up converter; Carrier multiplexing according to 55 outputs of the second parameter control module is counted n, the I road of adjusting the baseband signal after the clock frequency and the data transfer rate on Q road are carried out n/2 times of interpolation and filtering respectively, export I road signal after the interpolation and Q road signal to the many rate conversion module 51 of the fourth stage in the multiplexing mode of n carrier time-division.Wherein, transmit in the multiplexing mode of n carrier time-division respectively on the I road of the described baseband signal that receives and Q road; The clock frequency of Digital Up Convert equals the clock frequency of arbitrary module in the many rate conversion module 50 of the third level, the many rate conversion module 51 of the fourth stage, second level frequency mixing module 52 and the many rate conversion module 53 of level V.It is even number that carrier multiplexing is counted n.The many rate conversion module 50 of the third level adopt time-multiplexed mode that multi-carrier signal is handled when carrying out interpolation and filtering, have reduced expending of logical resource, have reduced hardware cost.

The many rate conversion module 51 of the fourth stage are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, in the mode that the n carrier time-division is multiplexing I road signal and the Q road signal that receives carried out many times of interpolations and filtering respectively, obtaining data transfer rate is the I road signal of a and the Q road signal that data transfer rate is a; Respectively I road signal and Q road signal are carried out many times of interpolations and filtering in the mode that the n/2 carrier time-division is multiplexing, obtaining data transfer rate is the I road signal of b and the Q road signal that data transfer rate is b, and exports I road signal and Q road signal to second level frequency mixing module 52 in the multiplexing mode of n/2 carrier time-division.Wherein, a equals the clock frequency of digital up converter and counts n divided by carrier multiplexing, and b equals the clock frequency of digital up converter and counts n/2 divided by carrier multiplexing; In other words, the numerical value of a be b numerical value 1/2nd.

Second level frequency mixing module 52 is counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, to receiving carrier wave stack and the mixing that the I road signal that transmits in the multiplexing mode of n/2 carrier time-division and Q road signal carry out the n carrier signal respectively, export I/Q two-way mixed frequency signal to the many rate conversion module 53 of level V in the multiplexing mode of 2 carrier time-divisions.Described I/Q two-way mixed frequency signal is I road mixed frequency signal and Q road mixed frequency signal; Second level frequency mixing module 52 can adopt existing carrier wave stacking method, carries out the carrier wave stack and the mixing of n carrier signal to the received signal, does not repeat them here.

The many rate conversion module 53 of level V are according to the frequency of the intermediate-freuqncy signal of the second parameter control module, 55 outputs, the I/Q two-way mixed frequency signal that receives is carried out c times of interpolation and filtering, export the I road of intermediate-freuqncy signal and Q road to digital to analog converter 54 in the multiplexing mode of 2 carrier time-divisions.Wherein, the data transfer rate of arbitrary road signal in the I/Q two-way mixed frequency signal that receives divided by the many rate conversion module 53 of level V of the c frequency that equals intermediate-freuqncy signal.

Preferably, also comprise a third level first-in first-out unit (not shown among Fig. 5) between many rate conversion module 53 of level V and the digital to analog converter 54.Third level first-in first-out unit is adjusted the clock frequency of I/Q two-way mixed frequency signal according to the clock frequency of the digital to analog converter 54 of the second parameter control module, 55 outputs, exports adjusted I/Q two-way mixed frequency signal to digital to analog converter 54.Why carrying out the adjustment of clock frequency, mainly is to consider to save the clock resource, reduces resource consumption.

Wherein, the many rate conversion module 50 of the third level comprise fourth stage first-in first-out unit 501, many times of interpolation units of the first order many times of interpolation units 502 and the second level 503

Fourth stage first-in first-out unit 501 is according to the I road of the baseband signal that receives and the clock frequency on Q road, and the clock frequency of digital up converter is adjusted into clock frequency sum more than or equal to the I road and the Q road of the baseband signal that receives; Many times of interpolation units in Q road to the second level 503 of baseband signal are exported to many times of interpolation units of the first order 502 in the I road of exporting baseband signal in the multiplexing mode of n carrier time-division in the multiplexing mode of n carrier time-division.Preferably, fourth stage first-in first-out unit 501 clock frequency of digital up converter is adjusted into the clock frequency of I road signal of the baseband signal that equals to receive and baseband signal Q road signal clock frequency and.

Many times of interpolation units of the first order 502 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, n/2 times of interpolation and filtering are carried out in the I road of butt joint As-received band signal, export I road signal to the many rate conversion module 51 of the fourth stage in the multiplexing mode of n carrier time-division.Many times of interpolation units of the first order 502 can adopt the combination of a plurality of filters that are used for many times of interpolations that are connected in series.

Many times of interpolation units in the second level 503 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, n/2 times of interpolation and filtering are carried out in Q road to the baseband signal that receives, export Q road signal to the many rate conversion module 51 of the fourth stage in the multiplexing mode of n carrier time-division.Many times of interpolation units in the second level 503 can adopt the combination of a plurality of filters that are used for many times of interpolations that are connected in series.

Wherein, the many rate conversion module of the fourth stage comprise many times of interpolation units of the third level 511, many times of interpolation units of the fourth stage 512, many times of interpolation units of level V 513 and the 6th grade of many times of interpolation units 514.

Many times of interpolation units of the third level 511 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, in the mode that the n carrier time-division is multiplexing the I road signal that receives being carried out d times of interpolation and filtering, is that the I road signal of a is to many times of interpolation units of level V 513 with the multiplexing mode output data rate of n carrier time-division.Wherein, d equals the merchant that the data transfer rate of the described I road signal that receives and product that carrier multiplexing is counted n obtain divided by the clock frequency of described digital up converter.

Many times of interpolation units of the fourth stage 512 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, in the mode that the n carrier time-division is multiplexing the Q road signal that receives being carried out d times of interpolation and filtering, is six grades of many times of interpolation units 514 of Q road signal to the of a with the multiplexing mode output data rate of n carrier time-division.

Many times of interpolation units of level V 513 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, is that the I road signal of a carries out 2 times of interpolations and filtering in the multiplexing mode of n/2 carrier time-division to the data transfer rate that receives, obtaining data transfer rate is the I road signal of b, and exports I road signal to second level frequency mixing module 52 in the multiplexing mode of n/2 carrier time-division.

The 6th grade of many times of interpolation units 514 are counted n according to the carrier multiplexing of the second parameter control module, 55 outputs, is that the Q road signal of a carries out 2 times of interpolations and filtering in the multiplexing mode of n/2 carrier time-division to the data transfer rate that receives, obtaining data transfer rate is the I road signal of b, and exports Q road signal to second level frequency mixing module 53 in the multiplexing mode of n/2 carrier time-division.

Wherein, second level frequency mixing module comprises second digital mixer 521, second digital controlled oscillator 522 and second complex mixer 523.

The second number control generators 522 are counted n according to the carrier multiplexing of the second parameter control module 55 output and the data transfer rate of the signal that receives, produce the 3rd orthogonal local oscillation signal and export second digital mixer 521 to.The frequency of the 3rd orthogonal local oscillation signal is that the merchant of incoming carrier frequency and sample rate be multiply by the product that 32 powers of 2 obtain again.

The 3rd orthogonal local oscillation signal that second digital mixer 521 is counted n and received according to the carrier multiplexing of the second parameter control module, 55 outputs, with the carrier wave stack that the time-multiplexed mode of n/2 is carried out the n carrier wave respectively to the I road signal that receives and Q road signal, I road signal and Q road signal to the second complex mixer 523 after the outgoing carrier stack.

I road signal and Q road signal after second complex mixer 523 superposes carrier wave carry out plural mixing, export I/Q two-way mixed frequency signal to the many rate conversion module 53 of level V with 2 carrier time-division multiplex modes.Second complex mixer 523 can adopt existing frequency mixing method, and the two paths of signals after the carrier wave stack is carried out mixing, does not repeat them here.

Wherein, the many rate conversion module 53 of level V comprise one the 7th grade of many times of interpolation unit 531.The 7th grade of many times of interpolation unit 531 are according to the frequency of the intermediate-freuqncy signal of the second parameter control module, 55 outputs, the I/Q two-way mixed frequency signal that receives is carried out c times of interpolation and filtering, export the I/Q two-way mixed frequency signal of intermediate-freuqncy signal to digital to analog converter 54 in the multiplexing mode of 2 carrier time-divisions.

In the above embodiment of the present invention, in order to obtain up-conversion signal preferably, the many rate conversion module 51 of the fourth stage further comprise first gain adjusting unit (not shown among Fig. 5) and second gain adjusting unit (not shown among Fig. 5).

First gain adjusting unit connects the many times of interpolation units of level V 513 and second digital mixer 521, range value according to the intermediate-freuqncy signal of the second parameter control module 55 output, I road signal to many times of interpolation units of level V 513 output carries out the signal amplitude adjustment, exports adjusted I road signal in the second level frequency mixing module 52 second digital mixer 521 in the time-multiplexed mode of n/2.

Second gain adjusting unit connects the 6th grade of many times of interpolation units 514 and second digital mixer 521, range value according to the intermediate-freuqncy signal of the second parameter control module 55 output, Q road signal to the 6th grade of many times of interpolation units 514 output carries out the signal amplitude adjustment, exports adjusted Q road signal in the second level frequency mixing module 52 second digital mixer 521 in the time-multiplexed mode of n/2.

Fig. 6 is the structural representation of digital up converter one embodiment of the present invention.As shown in Figure 6, in this embodiment, the carrier multiplexing number is 12.Now in conjunction with Fig. 6, the structure of this embodiment digital up converter is described, specific as follows:

The digital up converter of present embodiment comprises: the 4th first-in first-out unit 600, the 3rd radical sign raised cosine filter 601, the 4th radical sign raised cosine filter 602, the 4th FIR filter 603, the 5th FIR filter 604, the 6th FIR filter 605, the 7th FIR filter 606, the 6th half-band filter 607, the 7th half-band filter 608, first gain adjusting unit 609, second gain adjusting unit 610, digital mixer 611, digital controlled oscillator 612, complex mixer 613, the 8th half-band filter 614, the 3rd first-in first-out unit 615, digital to analog converter 616 and the second parameter control module (not shown among Fig. 6).

The 4th first-in first-out unit 600 is equivalent to fourth stage first-in first-out unit 501 shown in Figure 5.For the I road of realizing baseband signal and the 12 carrier time-division multiplexing process on Q road, the 4th first-in first-out unit 600 is with the 3rd radical sign raised cosine filter 601, the 4th radical sign raised cosine filter 602, the 4th FIR filter 603, the 5th FIR filter 604, the 6th FIR filter 605, the 7th FIR filter 606, the 6th half-band filter 607, the 7th half-band filter 608, first gain adjusting unit 609, second gain adjusting unit 610, digital mixer 611, digital controlled oscillator 612, the clock frequency of complex mixer 613 and the 8th half-band filter 614 becomes the clock frequency sum greater than the Q road signal of the clock frequency of the I road signal of baseband signal and baseband signal synchronously.Among this embodiment, the I road of baseband signal and the clock frequency on Q road all are 122.88MHz, and the clock frequency of the 4th first-in first-out unit 600 after synchronously is 276.48MHz, and data transfer rate keeps 1.28Ms/s constant.

The 3rd radical sign raised cosine filter 601 and the 4th FIR filter 603 have been formed many times of interpolation units of the first order among Fig. 5 502; The 4th radical sign raised cosine filter 602 and the 5th FIR filter 604 have been formed many times of interpolation units in the second level among Fig. 5 503.Among this embodiment, the 3rd radical sign raised cosine filter 601 and the 4th radical sign raised cosine filter 602 carry out 2 times of interpolations and filtering according to the parameter of second parameter control module output; The 4th FIR filter 603 and the 5th FIR filter 604 carry out 3 times of interpolations and filtering according to the parameter of second parameter control module output.In order to reduce the logical resource that takies, the I road signal that the 3rd radical sign raised cosine filter 601 and 603 pairs in the 4th FIR filter receive adopts the multiplexing mode of 12 carrier time-divisions when carrying out many times of interpolations, adopt the multiplexing mode of 12 carrier time-divisions when in like manner, the Q road signal that receives of the 4th radical sign raised cosine filter 602 and 604 pairs in the 5th FIR filter carries out many times of interpolations.The data transfer rate of the I road signal of the 4th FIR filter 603 outputs is 7.68Ms/s, and the data transfer rate of the Q road signal of the 5th FIR filter 604 outputs is 7.68Ms/s.

The 6th FIR filter 605 is equivalent to many times of interpolation units of the third level 511, the seven FIR filters 606 among Fig. 5 and is equivalent to many times of interpolation units of the fourth stage 512 among Fig. 6.Among this embodiment, the 6th FIR filter 605 and the 7th FIR filter 606 carry out 3 times of interpolations and filtering according to the parameter of second parameter control module output.Because the data transfer rate of the signal that receives and the product of carrier multiplexing number are less than clock frequency, the 6th FIR filter 605 and the 7th FIR filter 606 still adopt the multiplexing mode of 12 carrier time-divisions to carry out many times of interpolations to the received signal; The data transfer rate of the signal of the 6th FIR filter 605 and 606 outputs of the 7th FIR filter all is 23.04Ms/s.

The 6th half-band filter 607 is equivalent to many times of interpolation units of level V 513, the seven half-band filters 608 among Fig. 5 and is equivalent to the 6th grade of many times of interpolation units 514 among Fig. 5.Among this embodiment, the 6th half-band filter 607 and the 7th half-band filter 608 carry out 2 times of interpolations and filtering.Because this moment, the product of data transfer rate and carrier multiplexing number of the signal that receives needed less than clock frequency, at this moment, the 6th half-band filter 607 and the multiplexing mode of the 7th half-band filter 608 employing 6 carrier time-divisions are carried out the many times of interpolations and the filtering of signal.The signal data rate of the 6th half-band filter 607 and 608 outputs of the 7th half-band filter all is 46.08Ms/s.

First gain adjusting unit 609 is identical with first gain adjusting unit (Fig. 5 is not shown) of digital up converter of the present invention, second gain adjusting unit 610 is identical with second gain adjusting unit (Fig. 5 is not shown) of digital up converter of the present invention, no longer it is given unnecessary details at this.

Digital mixer 611 is equivalent to second digital mixer 521 among Fig. 5, and digital controlled oscillator 612 is equivalent to second digital controlled oscillator 522 among Fig. 5.What digital mixer 611 adopted is the carrier wave stack that the multiplexing mode of 6 carrier time-divisions is carried out 12 carrier waves to the received signal, and the signal after the output mixing is to complex mixer 613.Complex mixer 613 is equivalent to second complex mixer 523 among Fig. 5.I road and Q road signal after the carrier wave stack that 613 pairs of complex mixer receive carry out mixing, export I/Q two-way mixed frequency signal in the multiplexing mode of 2 carrier time-divisions.In the process of above-mentioned mixing and carrier wave stack, the clock frequency and the data transfer rate of signal remain unchanged.

The 8th half-band filter 614 is equivalent to the 7th grade of many times of interpolation units 531 among Fig. 5.According to the data transfer rate of required intermediate-freuqncy signal and the data transfer rate of the signal that receives, the 8th half-band filter 614 interpolation multiples are provided with.In the present embodiment, half-band filter carries out 2 times of interpolations and filtering; The data transfer rate of each road signal is 92.16Ms/s in the I/Q two-way mixed frequency signal of the 8th half-band filter 614 outputs.

The 3rd first-in first-out unit 615 is equivalent to the third level first-in first-out unit (not shown among Fig. 5) of digital up converter of the present invention, mainly is the clock frequency according to digital to analog converter 616, adjusts the clock frequency of the intermediate-freuqncy signal of output.Digital to analog converter 616 is equivalent to the digital to analog converter 54 among Fig. 5, does not repeat them here.

The above embodiment of the present invention only is to be illustrated for the situation that the signal in the passage is handled, if digital up converter of the present invention and digital down converter need be handled the signal in a plurality of passages, the first-in first-out unit that carries out the synchronised clock frequency in digital up converter then of the present invention and the digital down converter can carry out multiplexing at a plurality of interchannels, and the complex mixer of carrying out plural mixing in digital up converter of the present invention and the digital down converter can be carried out multiplexing by a plurality of again interchannels, can further reduce like this and take logical resource, reduce hardware cost, reduce the complexity of control signal and design simultaneously.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being made, is equal to replacement, improvement etc., all should be included within the scope of protection of the invention.

Claims

1. digital down converter, comprise the intermediate-freuqncy signal analog to digital converter of sampling that is used for input, it is characterized in that described digital down converter also comprises: first order frequency mixing module, the first parameter control module, the many rate conversion module of the many rate conversion module of the first order and the second level;

2. low-converter according to claim 1 is characterized in that, described first order frequency mixing module comprises:

3. low-converter according to claim 1 is characterized in that, the many rate conversion module of the described first order comprise:

4. low-converter according to claim 1 is characterized in that, the many rate conversion module in the described second level comprise:

5. low-converter according to claim 3 is characterized in that, it is 12 that described carrier multiplexing is counted n;

6. low-converter according to claim 4 is characterized in that, it is 12 that described carrier multiplexing is counted n; The many times of extracting units in the described second level comprise the 2nd FIR filter, the 4th half-band filter and the first radical sign raised cosine filter; Many times of extracting units of the described third level comprise the 3rd FIR filter, the 5th half-band filter and the second radical sign raised cosine filter;

7. digital up converter, comprise in order to digital signal is converted to the digital to analog converter of analog signal, it is characterized in that described digital up converter also comprises: the second parameter control module, the many rate conversion module of the third level, the many rate conversion module of the fourth stage, second level frequency mixing module and the many rate conversion module of level V;

8. upconverter according to claim 7 is characterized in that, also comprises a third level first-in first-out unit between many rate conversion module of described level V and the described digital to analog converter;

9. according to claim 7 or 8 described upconverter, it is characterized in that the many rate conversion module of the described third level comprise:

10. according to claim 7 or 8 described upconverter, it is characterized in that the many rate conversion module of the described fourth stage comprise:

11., it is characterized in that described second level frequency mixing module comprises according to claim 7 or 8 described upconverter:

12., it is characterized in that the many rate conversion module of described level V comprise one the 7th grade of many times of interpolation unit according to claim 7 or 8 described upconverter;

13. upconverter according to claim 10 is characterized in that, the many rate conversion module of the described fourth stage also comprise:

14. upconverter according to claim 9 is characterized in that, described n is 12; Many times of interpolation units of the described first order comprise the 3rd radical sign raised cosine filter and the 4th FIR filter; The many times of interpolation units in the described second level comprise the 4th radical sign raised cosine filter and the 5th FIR filter;

15. upconverter according to claim 13 is characterized in that,

Many times of interpolation units of the described third level are one to be used for the FIR filter of 3 times of interpolations and filtering;