CN102088426B - Method and device for controlling digital automatic gain - Google Patents

Abstract

The invention discloses a method and device for controlling digital automatic gain, and the method and device provided by the invention are used for solving the problems of great consumption of hardware resources and lower precision of automatic gain upon realization of digital automatic gain within a great dynamic range in the prior art. The method comprises: an automatic gain control device set on a base band side receives an input base band signal, acquires the virtual part and actual part of the base band signal and calculates a sum of the virtual and actual parts; the automatic gain control device determines a first automatic gain factor according to the sum, the length of the base band signal and an expected mean value of the automatic gain control device; the first automatic gain factor is regulated to obtain a second automatic gain factor according to a numerical value range to which the sum belongs; and the automatic gain control device carries out automatic gain control on the base band signal according to the second automatic gain factor. According to the technical scheme disclosed by the invention, hardware resources are saved, and the precision of automatic gain control is improved.

Description

A kind of control method of digital Auto Gain and device

Technical field

The present invention relates to the communications field, relate in particular to a kind of control method and device of digital Auto Gain.

Background technology

At present, AGC (Automatic Gain Control, automatic gain is controlled) be to be widely used in method that the automatic gain of communication system is controlled, AGC is mainly for adjusting the amplitude of signal, so that signal remains in a working range in the normal process process of subsequent module, the principle that AGC adjusts the amplitude of signal is mainly according to expecting requiring scaled down or the small-signal of input being amplified according to the equal proportion that requires of expectation working range of working range, to guarantee that signal meets the requirement of expecting working range by the large-signal of input.

In prior art, for obtaining the digital Auto Gain compared with great dynamic range, in digital automatic gain control system, introduce modulus hybrid feedback loop, so that ADC (Analog-to-Digital Converter, analog to digital converter) remains under higher signal to noise ratio working condition, signal is sampled.The mode of this introducing modulus hybrid feedback loop need to guarantee that digital loop and modulus mixing loop are consistent in loop characteristics, with expansion VGA (Variable-Gain Amplifier, variable gain amplifier) gain ranging, thus make whole modulus hybrid feedback loop in the situation that the digital Auto Gain of input great dynamic range can keep exporting to the power invariability of the signal of base band.

At present, by automatic gain control equipment, at digital intermediate frequency, realize the control to digital Auto Gain, at the constant signal of output data power to base band side, and detect feedback control loop maintenance compared with the digital Auto Gain of great dynamic range by interpolation, adopt this kind of mode to realize compared with the defect of the digital Auto Gain of great dynamic range to be: need to introduce modulus hybrid feedback circuit, and need to guarantee that digital loop and modulus hybrid feedback loop are consistent in loop characteristics, thereby the device that makes to form loop is more, safeguard that device is more complicated, the hardware resource consuming is more, and it is comparatively difficult to guarantee that digital loop and modulus hybrid feedback loop are consistent in loop characteristics, thereby make the accuracy of the digital Auto Gain control of signal lower.

Summary of the invention

The embodiment of the present invention provides a kind of control method and device of digital Auto Gain, for when realizing the digital Auto Gain of great dynamic range, reduces hardware resource consumption and improves the accuracy that digital Auto Gain is controlled.

A control method for digital Auto Gain, comprises step:

Device receives the baseband signal of input at the automatic gain control equipment of base band side, obtain imaginary part and the real part of this baseband signal and ask described imaginary part and real part and value;

Described automatic gain control equipment, according to described and value, the length of described baseband signal and the expectation average of this automatic gain control equipment, is determined the first automatic gain factor of described baseband signal;

Described automatic gain control equipment, according to the described and residing number range of value, is adjusted and is obtained the second automatic gain factor the described first automatic gain factor;

Described automatic gain is controlled according to the described second automatic gain factor, described baseband signal is carried out to automatic gain and control processing.

Described automatic gain control equipment is determined the first automatic gain factor of described baseband signal, is specially: according to the imaginary part of described baseband signal, real part and length, determine the signal average of this baseband signal; According to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, determine the first automatic gain factor of described baseband signal.

According to the imaginary part of described baseband signal, real part and length, determine the signal average of this baseband signal, specifically by following formula, obtain:

$\mathrm{\δ}=\frac{4\×\mathrm{sum}}{5\×\mathrm{length}\left(s\right)}$

In formula, δ is described baseband signal signal average, the imaginary part that sum is described baseband signal and real part and value, the length that length (s) is described baseband signal.

The first automatic gain factor of determining described baseband signal according to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, specifically obtains by following formula:

$\mathrm{agc}\_\mathrm{factor}=\frac{{\mathrm{\δ}}_{\mathrm{req}}}{\mathrm{\δ}}=\frac{{\mathrm{\δ}}_{\mathrm{req}}\×5\×\mathrm{length}\left(s\right)}{4\×\mathrm{sum}}$

In formula, the first automatic gain factor that agc_factor is described baseband signal, δ _reqfor the expectation average of described automatic gain control equipment, the length that lenth (s) is described baseband signal, the imaginary part that sum is described baseband signal and real part and value.

The described first automatic gain factor is adjusted and is obtained the second automatic gain factor, be specially:

According to the residing numerical value section of described sum, by the molecular moiety in the described first automatic gain factor

shift left, the ratio of the molecule after moving to left and described sum is defined as to the second automatic gain factor.

The maximum functional bit wide of setting described automatic gain control equipment is MAX bit;

According to the residing numerical value section of described sum, to described molecular moiety

shift left, be specially:

As sum > 2 ^yqtime, wherein $y=\frac{{\mathrm{\δ}}_{\mathrm{req}}\×5\×\mathrm{length}\left(s\right)}{4},$ (MAX-yq) bit that described y moved to left, the bit that yq is y;

When 2 ^lq< sum < 2 ^yqtime, (aq+lq-yq) bit that described y moved to left, wherein: aq is bit; Work as log ₂when (length (s)) is integer, lq=log ₂(length (s)), works as log ₂when (length (s)) is not integer,

As 1 < sum < 2 ^lqtime, zero bit moves to left described y.

Described automatic gain is controlled according to the described second automatic gain factor, described baseband signal is carried out to automatic gain and control processing, is specially:

Described baseband signal and the described second automatic gain factor are multiplied each other, and the product obtaining is carried out to corresponding dextroposition, and the baseband signal bit after shifting processing is saturated to the bit of the baseband signal of input; The bit number of described dextroposition with to described molecular moiety

the bit number shifting left equates.

A control device for digital Auto Gain, described device is arranged on base band side, and this device comprises acquisition module, automatic gain determination module, signal processing module, wherein:

Acquisition module, for receiving the baseband signal of input, obtain imaginary part and the real part of this baseband signal and ask described imaginary part and real part and value;

Automatic gain determination module, for according to described and value, the length of described baseband signal and the expectation average of described device, determines the first automatic gain factor of described baseband signal; And according to the described and residing number range of value, the described first automatic gain factor is adjusted and obtained the second automatic gain factor;

Signal processing module, for according to the described second automatic gain factor, carries out automatic gain to described baseband signal and controls processing.

Described automatic gain determination module is determined the first automatic gain factor of described baseband signal, is specially: according to the imaginary part of described baseband signal, real part and length, determine the signal average of this baseband signal; According to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, determine the first automatic gain factor of described baseband signal.

Described automatic gain determination module, according to the imaginary part of described baseband signal, real part and length, is determined the signal average of this baseband signal, specifically by following formula, obtains:

$\mathrm{\&delta;}=\frac{4\&times;\mathrm{sum}}{5\&times;\mathrm{length}\left(s\right)}$

In formula, the signal average that δ is described baseband signal, the imaginary part that sum is described baseband signal and real part and value, the length that length (s) is described baseband signal.

Described automatic gain determination module is determined the first automatic gain factor of described baseband signal according to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, specifically by following formula, obtain:

$\mathrm{agc}\_\mathrm{factor}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}}{\mathrm{\&delta;}}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4\&times;\mathrm{sum}}$

In formula, the first automatic gain factor that agc_factor is described baseband signal, δ _reqfor the expectation average of described automatic gain control equipment, the length that length (s) is described baseband signal, the imaginary part that sum is described baseband signal and real part and value.

Described automatic gain determination module is adjusted and is obtained the second automatic gain factor the described first automatic gain factor, is specially:

According to the residing numerical value section of described sum, by the molecular moiety in the described first automatic gain factor

shift left, the ratio of the molecule after moving to left and described sum is defined as to the second automatic gain factor.

The maximum bit wide that described automatic gain determination module is further used for setting described baseband signal is MAX bit;

Described automatic gain determination module is according to the residing numerical value section of described sum, to described molecular moiety

shift left, be specially:

As sum > 2 ^yqtime, wherein $y=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4},$ (MAX-yq) bit that described y moved to left, the bit that yq is y;

When 2 ^lq< sum < 2 ^yqtime, (aq+lq-yq) bit that described y moved to left, wherein: aq is

bit; Work as log ₂when (length (s)) is integer, lq=log ₂(length (s)), works as log ₂when (length (s)) is not integer,

As 1 < sum < 2 ^lqtime, zero bit moves to left described y.

Described signal processing module, according to the described second automatic gain factor of determining, carries out automatic gain to described baseband signal and controls processing, is specially:

Described baseband signal and the described second automatic gain factor are multiplied each other, and the product obtaining is carried out to corresponding dextroposition, and the baseband signal bit after shifting processing is saturated to the bit of the baseband signal of input; The bit number of described dextroposition with to described molecular moiety

the bit number shifting left equates.

In the embodiment of the present invention, on the one hand, automatic gain control equipment is arranged on to base band side, in base band side, baseband signal is carried out to automatic gain and control processing, thereby overcome prior art and by automatic gain control equipment, signal has been carried out to the more problem of hardware resource that automatic gain control processing causes consumption at intermediate frequency, adopt technical solution of the present invention, do not need to add loop circuit and only by automatic gain control equipment, can realize the automatic gain of signal is controlled and processed, thereby saved hardware resource, on the other hand, automatic gain control equipment is being determined the second automatic gain for baseband signal is carried out to automatic gain control because of the period of the day from 11 p.m. to 1 a.m, it is (described different with the residing number range of value that the first automatic gain factor of determining from real part and the residing number range adjustment of value according to the imaginary part of this baseband signal obtains the second automatic gain factor, also different to the adjustment mode of the first automatic gain factor, thereby make the value of the second automatic gain factor that obtains also different), thereby make the information of the required reservation of the automatic gain factor that the baseband signals for different sizes obtain different, therefore, according to this automatic gain factor pair signal, carry out automatic gain and control the accuracy that has improved automatic gain control.

Accompanying drawing explanation

Fig. 1 is the method flow diagram of in the embodiment of the present invention, digital Auto Gain being controlled;

Fig. 2 is the apparatus structure schematic diagram of in the embodiment of the present invention, digital Auto Gain being controlled.

Embodiment

The main thought of technical solution of the present invention is, existing AGC device is arranged on to base band side, and baseband signal is carried out to automatic gain and control processing, when baseband signal being carried out to AGC processing, according to baseband signal imaginary part, with size value, the automatic gain factor of determining is carried out to different adjustment processing from real part, according to the automatic gain factor pair baseband signal after adjusting, carrying out automatic gain again and control processing, as for large-signal, is the signal of preserving decimal; For msp signal, be mainly the precision that improves AGC gain factor, in the working range allowing, retain more gain factor information; And for small-signal, retain more integer information; With the digital Auto Gain realizing in a big way, control.

Below in conjunction with Figure of description, the embodiment of the present invention is described in detail.

Referring to Fig. 1, be the method flow diagram of in the embodiment of the present invention, digital Auto Gain being controlled, the method flow process is applied in existing AGC device (this AGC device is arranged on base band side), and this flow process comprises the following steps:

Step 101, AGC device, for each group baseband signal (representing with S) of inputting, obtain each baseband signal in S and (use S _iexpression) imaginary part (is used im _irepresent) (use re with real part _irepresent) numerical value, and the expectation average of determining this AGC device (is used δ _reqrepresent).

Step 102, the imaginary part of determining all baseband signals in this group baseband signal and real part and value, and according to this and value, this group length of baseband signal and expectation average δ of AGC device _req, determine the first automatic gain factor (representing with agc_factor) of this group baseband signal S.

Step 103, by comparing with value and a plurality of and value threshold value of setting of determining in step 102, and according to comparative result, this first automatic gain factor is adjusted, obtain the second automatic gain factor of processing for the digital Auto Gain of this group baseband signal S is controlled.

The second automatic gain factor that step 104, basis are determined, controls processing to the digital Auto Gain of this group baseband signal S.

In the step 101 of above-mentioned flow process, determine the expectation average δ of AGC device _reqspecific implementation be: according to allowing the operation level value of this AGC device and the peak-to-average force ratio of intermediate frequency data to determine the expectation average δ of this AGC device _req.

In the step 102 of above-mentioned flow process, the automatic gain factor agc_factor that determines this group baseband signal S can adopt following formula (1) to obtain:

$\mathrm{agc}\_\mathrm{factor}={\mathrm{\&delta;}}_{\mathrm{req}}/\mathrm{\&delta;}={\mathrm{\&delta;}}_{\mathrm{req}}/\left(\sqrt{\frac{({\mathrm{re}}^2+{\mathrm{im}}^2)}{\mathrm{length}\left(s\right)}}\right)$ Formula (1)

In formula (1), δ _reqexpectation average for this AGC device, δ is the signal average of this group baseband signal S, im be this group baseband signal all baseband signals imaginary part and value, the real part that re is all baseband signals of this group baseband signal S and value, length (s) is this length value of organizing baseband signal S.

Due in actual applications, too complicated to the processing of signal, therefore, the embodiment of the present invention is simplified formula (1), simplifies as follows: the mathematic(al) representation of this group baseband signal S is S=r * e ^{j θ}, θ ∈ (0,2 π) wherein, can obtain the signal average (with ξ represent) of this group baseband signal under polar coordinates by following formula (2) according to mathematical formulae:

$\mathrm{\&xi;}=\underset{0}{\overset{2\mathrm{\&pi;}}{\&Integral;}}\frac{|r\&times;\cos \mathrm{\&theta;}|+|r\&times;\sin \mathrm{\&theta;}|}{2\mathrm{\&pi;}}{d}_{\mathrm{\&theta;}}\&DoubleRightArrow;\mathrm{\&xi;}=(4/\mathrm{\&pi;})\&times;r\&DoubleRightArrow;\mathrm{\&xi;}=\&ap;\frac{5}{4}\&times;r$ Formula (2)

According to the ξ calculating, the signal average δ that determines this group baseband signal S can be simplified to as shown in the formula shown in (3) again:

$\mathrm{\&delta;}=\frac{4\&times;[\mathrm{re}+\mathrm{im}]}{5\&times;\mathrm{length}\left(s\right)}$ Formula (3)

In formula (3), δ is the signal average of baseband signal S, im be this group baseband signal all baseband signals imaginary part and value, the real part that re is all baseband signals of this group baseband signal S and value, length (s) is this length value of organizing baseband signal S.

Signal average δ based on after simplifying, the automatic gain factor agc_factor that can replace this group baseband signal after can being simplified by simple formula is as shown in the formula shown in (4):

$\mathrm{agc}\_\mathrm{factor}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4\&times;\mathrm{sum}}$ Formula (4)

In formula (4), agc_factor for this group baseband signal simplification after the automatic gain factor, length (s) is the length value of this group baseband signal S, the imaginary part that sum is all baseband signals in this group baseband signal and real part and be worth, this sum and aforesaid (re+im) physical meaning, numerical value are identical.

In step 103 in above-mentioned flow process, the specific implementation of determining the second automatic gain factor is as follows: according to practical application, the resource limitation of the multiplier in combined with hardware, adder and divider, the maximum functional bit wide of setting this group AGC device is MAX bit, and the value of MAX can be set based on experience value; According to the value of sum, three and value threshold value are set, first and value threshold value setting are 2 ^yq(the bit bit wide that yq is y), second and value threshold value setting be 2 ^lq(lq is the bit bit wide of sum segmentation boundary), the 3rd is 1 with value threshold value setting, wherein $y=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4};$ Above-mentioned three and the value threshold value of sum and setting are compared, and according to comparative result, the first automatic gain factor being adjusted to the second automatic gain factor obtaining has three kinds of values: as sum > 2 ^yqtime, (MAX-yq) bit that y moved to left obtains y ', and obtaining the second automatic gain factor is y '/sum; When 2 ^lq< sum < 2 ^yqtime, the bit range of y/sum is [1, (yq-lq)], y/sum is represented with aq bit, (aq+lq-yq) bit that y moved to left obtains y ", obtaining the second automatic gain factor is y "/sum, wherein lq can obtain according to following formula (5) or formula (6); As 1 < sum < 2 ^lqtime, the second automatic gain factor is y/sum, now, because signal is less, can be using the second automatic gain factor as a definite value (being aq bit).

Work as log ₂when (length (s)) is integer, can obtain lq suc as formula shown in (5):

Lq=log ₂(length (s)) formula (5)

Work as log ₂when (length (s)) is not integer, can obtain lq suc as formula shown in (6):

formula (6)

In the step 104 of above-mentioned flow process, according to the second automatic gain factor of determining, digital Auto Gain to this group baseband signal S is controlled processing, specific implementation is as follows: the baseband signal S ' that this group baseband signal S and the second automatic gain factor determined are multiplied each other after being processed, then the baseband signal S ' after processing carries out corresponding shifting processing and is saturated to the length (representing with sq bit) of this group baseband signal S; To processing the baseband signal S ' obtaining, carry out corresponding shifting processing, specific implementation is as follows:

When the second automatic gain factor obtaining is y '/sum, (MAX-yq) bit position moves to right S ';

When the second automatic gain factor obtaining is y, " during/sum, (aq+lq-yq) bit position moves to right S ';

When the second automatic gain factor obtaining is y/sum, do not need S ' to carry out shifting processing.

Preferably, the data volume of processing in order to reduce AGC device.Improve treatment effeciency, in the embodiment of the present invention, for standard, be LTE (Long Time Evoluton, Long Term Evolution), TDD (Time DivisionDuplexing, time division duplex) and RACH (Radom Access Channel, Random Access Channel), at receiving terminal, AGC device is arranged on to down-sampled equipment and FFT (Fast Fourier Transformation, fast fourier transform) between equipment, carry out BBU (Baseband unit, baseband processing unit) AGC of side processes, thereby simplified power operation and opened root computing, greatly reduce the operand of AGC device, reduce resource consumption, improve speed.

For more detailed, clearer description technical solution of the present invention, below with a concrete example to digital Auto Gain being controlled and is described in detail in technical solution of the present invention.

Suppose the peak-to-average force ratio PAPR=12dB of intermediate frequency data, the amount of redundancy of reserved 2dB, determining the work expectation of the baseband signal of current input is-14dB; According to 20logx=-14, obtain x=10 ^-0.7, and this x is quantized to obtain the expectation average σ of this input signal _reqbe 6538, the data that input signal s is 16bit, by the real part of this input signal and imaginary part be added obtain with value sum be 16bit; The length l ength of this input signal (s)=1536; The maximum bit wide that the transmitting form (repeating form) of taking into account all RACH obtains sum is 28bit; Owing to considering the environment of real work, it is 34bit that maximum permission unsigned number is set.

According to above-mentioned parameter, as follows to the control flow of digital Auto Gain:

Step 1, the real part of input signal and imaginary part are added, obtain and be worth sum=28bit;

Step 2, the x that calculates this input signal according to preceding method are σ _req* 5 * length (s), converting position, broadband to is 26bit;

Step 3: the x that step 2 is obtained moves to right, and to obtain y be 24bit to 2bit (be about to x divided by 4);

Step 4: according to the value of sum, by comparing with value threshold value of sum and setting, and determine the second automatic gain factor according to comparative result, then according to the second automatic gain factor pair input signal of determining, carry out the automatic gain factor and control processing, the signal after being processed output.

As sum > 2 ²³time, the y of the 24bit 15bit that moves to left is obtained to y ', then y ' and the ratio of sum are obtained to the second automatic gain factor of 16bit, then the input signal that this second automatic gain factor and length are 16bit is multiplied each other and obtains the processing signals of 32bit; Again this processing signals is moved to right 15bit and be saturated to 16bit after export.

When 2 ¹¹< sum < 2 ²³time, the y of the 24bit 3bit that moves to left is obtained to y ", then by y " and the ratio of sum obtains the second automatic gain factor of 16bit, then the input signal that this second automatic gain factor and length are 16bit is multiplied each other and obtains the processing signals of 32bit; Again this processing signals is moved to right 3bit and be saturated to 16bit after export.

When for 1 < sum < 2 ¹¹time, the y value obtaining is smaller, can directly the ratio of y and sum be defined as to the second automatic gain factor, and exports after being saturated to 16bit.

This method technical scheme is mainly used in carries out digital Auto Gain control to the baseband signal in LTE standard, TDD standard, but be not limited in above-mentioned network environment, also can promote the use of other network environments, such as: to PUSCH (Physical Uplink Shared Channel, Physical Uplink Shared Channel), the baseband signal in the channel such as PUCCH (Physical Uplink Control Channel, Physical Uplink Control Channel), RACH is carried out automatic gain and is controlled and process; To LTE-TDD (Long Time Evoluton-Time DivisionDuplexing, the time division duplex of Long Term Evolution), LTE-FDD (Long Time Evoluton-FrequencyDivision Duplex, Long Term Evolution Frequency Division Duplexing (FDD)), TD-SCDMA (Time Division-SynchronousCode Division Multiple Access, TD SDMA access), the baseband signal in WCDMA (WidebandCode Division Multiple Access, Wideband Code Division Multiple Access (WCDMA) access) is carried out automatic gain control processing; Situation large for divisor dynamic range and that required precision is higher is also suitable for technical solution of the present invention signal is carried out to automatic gain control processing.

Based on the identical design of above-mentioned flow process, the embodiment of the present invention also provides a kind of control device of digital Auto Gain, and the structural representation of this device as shown in Figure 2.

Referring to Fig. 2, be the structural representation of a kind of digital AGC of providing in the embodiment of the present invention, this device comprises acquisition module 21, automatic gain determination module 22, signal processing module 23, wherein:

Acquisition module 21, for receiving the baseband signal of input, obtain imaginary part and the real part of this baseband signal and ask the imaginary part of this baseband signal and real part and value.

Automatic gain determination module 22, for and the length of value, this baseband signal and the expectation average of this device that obtain according to acquisition module 21, determines the first automatic gain factor of this baseband signal; And according to the imaginary part of this baseband signal and real part with value residing number range, the second automatic gain factor is adjusted and obtained to the first automatic gain factor.

Signal processing module 23, for the second automatic gain factor of determining according to automatic gain determination module 22, carries out automatic gain to this baseband signal and controls processing.

Automatic gain determination module 22 is divided and can be divided into first definite submodule 221 and automatic gain factor adjustment submodule 222 according to function, wherein:

First determines submodule 221, for expectation average that obtain according to acquisition module 21 and value and this device, determines the first automatic gain factor of this baseband signal.

First definite submodule 221, according to the imaginary part of this baseband signal, real part and length, is determined the signal average of this baseband signal; And according to the signal average of the expectation average of automatic gain control equipment and this baseband signal, determine the first automatic gain factor of described baseband signal.

First determines that the concrete how to confirm of submodule 221 goes out the signal average of baseband signal, and how according to the signal average of the expectation average of automatic gain control equipment and baseband signal, to determine the first automatic gain factor, consistent with the mode described in aforementioned flow process, do not repeat them here.

The automatic gain factor is adjusted submodule 222, for according to the imaginary part of this baseband signal and real part be worth residing number range, the second automatic gain factor is adjusted and obtained to the first automatic gain factor.

Automatic gain is adjusted submodule 222 and how the first automatic gain factor is adjusted that to obtain the mode of the second automatic gain factor consistent with the mode of aforementioned flow process description, does not repeat them here.

The second automatic gain factor how above-mentioned signal processing module 23 is determined according to automatic gain determination module 22, the mode of this baseband signal being carried out to automatic gain control processing is consistent with the mode of aforementioned flow process description, does not repeat them here.

Adopt technical solution of the present invention, there is following technique effect:

(1) in the embodiment of the present invention, AGC device is carried out to automatic gain in base band side to baseband signal and control processing, in processing procedure, for varying in size of baseband signal, carry out different processing, thereby only need to adopt existing AGC device not need as needing to add hardware in prior art, can realize larger digital Auto Gain and control dynamic range.Therefore, technical solution of the present invention can be saved hardware resource, and has simplified the maintenance work in later stage.

(2) in base band side, baseband signal is carried out to automatic gain and control processing, can meet compared with the requirement of great dynamic range signal, do not need that signal is carried out to amplitude limiting processing and need to when signal is exported, not do saturated processing yet, realized and signal is in a big way carried out to linearity amplified and linear narrowing, and can carry out different processing to large, medium and small signal, the gain factor that every kind of signal obtains is also preferentially retained because of the difference of the information of required reservation, thereby has improved the accuracy that signal automatic gain is controlled.

(3) signal is being carried out in the process of automatic gain control, for signal magnitude difference, carry out different processing, thereby better meet the requirement of multiplier hardware attribute, do not need to use a plurality of multiplier resources to form a large multiplier resources, therefore, adopt technical solution of the present invention only need to use a multiplier can meet plurality word automatic gain and control dynamic range, thereby effectively save multiplier, reduce resources occupation rate.

Obviously, those skilled in the art can carry out various changes and modification and not depart from the spirit and scope of the present invention the present invention.Like this, if within of the present invention these are revised and modification belongs to the scope of the claims in the present invention and equivalent technologies thereof, the present invention is also intended to comprise these changes and modification interior.

Claims (6)

1. a control method for digital Auto Gain, is characterized in that, comprises step:

The automatic gain control equipment that is arranged on base band side receives the baseband signal of input, obtain imaginary part and the real part of this baseband signal and ask described imaginary part and real part and value;

Described automatic gain control equipment, according to the imaginary part of described baseband signal, real part and length, is determined the signal average of this baseband signal; According to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, determine the first automatic gain factor of described baseband signal;

Described automatic gain control equipment, according to the described and residing number range of value, shifts left the molecular moiety in the described first automatic gain factor, and the molecule after moving to left and described and ratio value are defined as to the second automatic gain factor;

Described automatic gain control equipment, according to the described second automatic gain factor, carries out automatic gain to described baseband signal and controls processing;

Wherein, described automatic gain control equipment, according to the described and residing number range of value, shifts left the molecular moiety in the described first automatic gain factor, comprising:

Work as sum>2 ^yqtime, wherein

(MAX-yq) bit that described y moved to left, the bit that yq is y;

When 2 ^lq<summ<2 ^yqtime, (aq+lq-yq) bit that described y moved to left, wherein: aq is

bit; Work as log ₂when (length (s)) is integer, lq=log ₂(length (s)), works as log ₂when (length (s)) is not integer,

Work as 1<sum<2 ^lqtime, zero bit moves to left described y;

Wherein, the maximum functional bit wide that MAX is described automatic gain control equipment, unit is bit; Sum be the imaginary part of described baseband signal and real part and value; Described molecular moiety is

Described automatic gain control equipment is according to the described second automatic gain factor, described baseband signal is carried out to automatic gain and control processing, be specially: described baseband signal and the described second automatic gain factor are multiplied each other, and the product obtaining is carried out to corresponding dextroposition, and the baseband signal bit after shifting processing is saturated to the bit of the baseband signal of input; The bit number of described dextroposition with to described molecular moiety

the bit number shifting left equates.

2. the method for claim 1, is characterized in that, according to the imaginary part of described baseband signal, real part and length, determines the signal average of this baseband signal, specifically by following formula, obtains:

$\mathrm{\&delta;}=\frac{4\&times;\mathrm{sum}}{5\&times;\mathrm{length}\left(s\right)}$

In formula, δ is described baseband signal signal average, the imaginary part that sum is described baseband signal and real part and value, the length that length (s) is described baseband signal.

3. method as claimed in claim 2, is characterized in that, determines the first automatic gain factor of described baseband signal according to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, specifically by following formula, obtains:

$\mathrm{agc}\_\mathrm{factor}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}}{\mathrm{\&delta;}}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4\&times;\mathrm{sum}}$

In formula, the first automatic gain factor that agc-factor is described baseband signal, δ _reqfor the expectation average of described automatic gain control equipment, the length that length (s) is described baseband signal, the imaginary part that sum is described baseband signal and real part and value.

4. a control device for digital Auto Gain, is characterized in that, described device is arranged on base band side, and this device comprises acquisition module, automatic gain determination module, signal processing module, wherein:

Acquisition module, for receiving the baseband signal of input, obtain imaginary part and the real part of this baseband signal and ask described imaginary part and real part and value;

Automatic gain determination module, be used for according to the imaginary part of described baseband signal, real part and length, determine the signal average of this baseband signal, according to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, determine the first automatic gain factor of described baseband signal; And according to the described and residing number range of value, the molecular moiety in the described first automatic gain factor is shifted left, the molecule after moving to left and described and ratio value are defined as to the second automatic gain factor;

Signal processing module, for according to the described second automatic gain factor, carries out automatic gain to described baseband signal and controls processing;

Wherein, described automatic gain determination module specifically for:

Work as sum>2 ^yqtime, wherein

(MAX-yq) bit that described y moved to left, the bit that yq is y;

When 2 ^lq<sum<2 ^yqtime, (aq+lq-yq) bit that described y moved to left, wherein: aq is

bit; Work as log ₂when (length (s)) is integer, lq=log ₂(length (s)), when log2 (length (s)) is not integer, lq=

Work as 1<sum<2 ^lqtime, zero bit moves to left described y;

Wherein, the maximum functional bit wide that MAX is described automatic gain control equipment, unit is bit; Sum be the imaginary part of described baseband signal and real part and value; Described molecular moiety is

Described signal processing module is according to the described second automatic gain factor of determining, described baseband signal is carried out to automatic gain and control processing, be specially: described baseband signal and the described second automatic gain factor are multiplied each other, and the product obtaining is carried out to corresponding dextroposition, and the baseband signal bit after shifting processing is saturated to the bit of the baseband signal of input; The bit number of described dextroposition with to described molecular moiety the bit number shifting left equates.

5. device as claimed in claim 4, is characterized in that, described automatic gain determination module, according to the imaginary part of described baseband signal, real part and length, is determined the signal average of this baseband signal, specifically by following formula, obtains:

$\mathrm{\&delta;}=\frac{4\&times;\mathrm{sum}}{5\&times;\mathrm{length}\left(s\right)}$

In formula, the signal average that δ is described baseband signal, the imaginary part that sum is described baseband signal and real part and value, the length that length (s) is described baseband signal.

6. device as claimed in claim 5, it is characterized in that, described automatic gain determination module is determined the first automatic gain factor of described baseband signal according to the signal average of the expectation average of described automatic gain control equipment and described baseband signal, specifically by following formula, obtain:

$\mathrm{agc}\_\mathrm{factor}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}}{\mathrm{\&delta;}}=\frac{{\mathrm{\&delta;}}_{\mathrm{req}}\&times;5\&times;\mathrm{length}\left(s\right)}{4\&times;\mathrm{sum}}$

In formula, the first automatic gain factor that agc-factor is described baseband signal, δ _reqfor the expectation average of described automatic gain control equipment, the length that length (s) is described baseband signal, the imaginary part that sum is described baseband signal and real part and value.

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