Summary of the invention
Given this, the objective of the invention is to provide a kind of frequency the blind method and apparatus of sweeping for the long problem of the blind flyback time of present frequency.
For overcoming the above problems, the invention provides the blind method of sweeping of a kind of fast frequency point, construct the power spectrum signal of whole frequency band, with predetermined step-length and predetermined window power spectrum signal is scanned, predetermined window internal power value summation is obtained the broadband power array, and search broadband power array obtains the center frequency point position.
Preferably, but as the another kind implementation, as shown in Figure 1, before with predetermined step-length and predetermined window power spectrum signal being scanned, the frequency band power after also comprising disabled frequency range in the power spectrum signal of whole frequency band and finishing frequency is set to zero.
Preferably, the power spectrum signal of the whole frequency band of described structure as shown in Figure 2, comprising:
201: according to the frequency range of high-rise appointment, determine the number K of scanning frequency,
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth,
Expression rounds up;
202: according to the frequency point scanning order, the scanning frequency, the yield value of adjustment AGC switches to initial frequency;
203: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, to a radio frames receiving according to this N_FFT be length, be divided into M sub-block, be that the time domain data of N_FFT is made the fast Fourier transform FFT that N_FFT is ordered to each sub-block length, and carry out frequency spectrum screening according to the receiver pass-band bandwidth, and obtaining sub-block frequency-region signal power spectrum, M sub-block frequency-region signal power spectrum superposeed obtains power spectrum signal in the W bandwidth;
204: power spectrum signal is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
205: switch to next scanning frequency, repeating step 203 steps 205;
206: by K structure, obtain the power spectrum signal of whole frequency band.
Preferably, but as the another kind implementation, the power spectrum signal of the whole frequency band of described structure comprises:
211: according to the frequency range of high-rise appointment, determine the number K of scanning frequency,
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth,
Expression rounds up;
212: according to the frequency point scanning order, the scanning frequency, the yield value of adjustment AGC switches to initial frequency;
213: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, initialization arrowband power array Norrow_Power passes through the optional network specific digit filter successively with the time domain data that receives, and measures the arrowband power Norrow_Power of i frequency
i, the value of i from 0 to
Wherein, described optional network specific digit filter bandwidht is the channel grid Δ f of system's regulation, and center frequency point is f_initial+ Δ f/2+i Δ f,
Expression rounds downwards;
214: arrowband power array is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
215: switch to next scanning frequency, repeating step 213~step 215;
216: by K structure, obtain the power spectrum signal of whole frequency band.
Preferably, the yield value of described adjustment AGC comprises:
202A: be empirical value with the AGC gain value settings in advance, preferably be configured such that all undersaturated arbitrary values of each frequency receiver;
202B. initialization frequency AGC gain array AGC_Freq
kBe the full 0 array, wherein K is the scanning frequency points, and the k value is from 1 to K;
202C. according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 radio frames time domain data;
202D. a radio frames time domain data that will receive is divided into the N piece, every data length is L, calculates every blocks of data average power:
I=1 wherein, 2 ..., N, I represent to receive the real part of time domain data, and Q represents to receive the imaginary part of time domain data
202E. find out each blocks of data average power peak value, gain adjusts accordingly to AGC with this performance number;
202F. again receive a radio frames time domain data, repeating step 202D, 202E are assigned to AGC_Freq until the satisfied AGC yield value is adjusted to satisfied preset value with described final AGC yield value
kMiddle correspondence position;
Preferably, but as the another kind implementation, the yield value of described adjustment AGC comprises:
202a. initialization frequency AGC gain array AGC_Freq
kBe the full 0 array, wherein K is the scanning frequency points, and the k value is from 1 to K;
202b. be maximum in advance with the AGC gain value settings, according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 radio frames time domain data;
202c. measure this time domain data, obtain maximum power value P1;
202d. the automatic gain of terminal receiver amplifier is reduced a rank, remeasure the data that receive continuously on this frequency, obtain second maximum power value P2;
202e. calculate the difference between second maximum power value and first maximum power value, and compare with the power difference threshold of setting;
If adjust accordingly 202f. difference less than thresholding, will gain to AGC with second maximum power value; If difference is greater than thresholding, then power measurement values returns to step 202d as the power measurement values first time for the second time.
202g. if AGC has been down to minimum rank, then get maximum corresponding to this frequency the AGC yield value is adjusted accordingly, deposit final AGC yield value in AGC gain array AGC_Freq
kCorrespondence position.
Preferably, described predetermined step-length is that described predetermined window is system bandwidth less than the maximum of the channel grid of system's regulation.
Preferably, described predetermined step-length is the maximum less than 2~3 times of system's predetermined channel grids.
Preferably, all frequency broadband power arrays of described search obtain the center frequency point position and are search broadband power array power maximum, and frequency corresponding to this maximum is the center frequency point position.
Preferably, but as the another kind implementation, all frequency broadband power arrays of described search obtain the center frequency point position, search broadband power array power maximum, get 3~10 frequencies at frequency frequency the right and left that this maximum is corresponding, receive time domain data, record each frequency performance number, position corresponding to search maximum power value is the center frequency point position.
For overcoming the above problems, the present invention also provides a kind of frequency blind sweeping device, comprising:
Whole frequency band power spectrum signal constructing module is used for the interior power spectrum of frequency band range that tectonic system is stipulated;
The broadband power computing module is used for the full frequency band power spectrum to structure, scans with the predetermined window of predetermined step-length, and the window internal power is superposeed obtains full frequency band frequency point broadband power distribution array;
The center frequency point search module, be used for choosing frequency corresponding to full frequency band frequency point broadband power distribution array maximum power value as the center frequency point position, perhaps get 3~10 frequencies on the frequency both sides corresponding to maximum power value of full frequency band frequency point broadband power distribution array, receive time domain data at each frequency, record its performance number, then choose frequency centered by frequency corresponding to power maximum.
Preferably, described Whole frequency band power spectrum signal constructing module comprises:
The time domain data processing unit is used for calculating scanning frequency points K, with predetermined frequency interval, adjusts the yield value of automatic gain control AGC, receives time domain data take frame as unit;
The power spectrum structural unit, be used for the time domain data that certain frequency receives is divided into M sub-block, every blocks of data carried out N_FFT point quick Fourier conversion FFT, according to the receiver pass-band bandwidth, structure passband power spectrum carries out same operation structure full frequency band power spectrum to K frequency.
Preferably, described Whole frequency band power spectrum signal constructing module also comprises: the power culling unit, the power setting that is used for the frequency range behind the disabled frequency range of full frequency band power spectrum and the end frequency is zero.
The present invention is mainly by utilizing a small amount of time domain data that receives by FFT structure full frequency band power spectrum, only need in the power spectrum of structure, to search for corresponding frequency broadband power maximum and just can determine the center frequency point position, compared with prior art, the present invention only needs just can construct the full frequency band power spectrum by limited several frames, greatly reduced and searched frame time, thereby reached the blind purpose of sweeping of fast frequency point.
Embodiment
For clearly demonstrating the solution of the present invention, the below provides preferred embodiment and by reference to the accompanying drawings the present invention is made a detailed description, among the application,
Represent to round up,
Expression rounds downwards, X (M:N) represents that value is from X (M) to X (N).
The below is respectively take LTE system and TD-SCDMA system as example, the blind method of sweeping of a kind of frequency of the present invention is described, construct the power spectrum signal of whole frequency band, with predetermined step-length and predetermined window power spectrum signal is scanned, predetermined window internal power value summation is obtained the broadband power array, and search broadband power array obtains the center frequency point position.
For the LTE system, referring to Fig. 3, a radio frames is comprised of 10 subframes, and total length is 327200Ts, and the duration is 10ms.
The power spectrum signal of the whole frequency band of described structure comprises:
Step 11: according to the frequency range of high-rise appointment, determine the number K of scanning frequency
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth, and this pass band width is larger, and frequency points to be scanned is just fewer;
Hypothesis pass band width W is 20M in the present embodiment, and f_initial is 2300MHz, and f_end is 2400MHz, and then scanning frequency points K is 5;
Step 12: according to the frequency point scanning order, get successively each scanning frequency f, the yield value of AGC is set, switch to initial frequency,
Make f=f_initial+ (p-1) W+W/2, p is from 1 to K value successively, and for the LTE system, a wireless frame data length is 307200Ts;
Step 13: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, to a radio frames receiving according to this N_FFT be length, be divided into M sub-block, be that the time domain data of N_FFT is made the fast Fourier transform FFT that N_FFT is ordered to each sub-block length, and carry out frequency spectrum screening according to the receiver pass-band bandwidth, and obtaining sub-block frequency-region signal power spectrum, M sub-block frequency-region signal power spectrum superposeed obtains power spectrum signal in the W bandwidth
In the present embodiment, N_FFT=2048, M=150;
Step 14: power spectrum signal is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
Step 15: switch to next scanning frequency, repeating step 13~step 15;
Step 16: by K structure, obtain the power spectrum signal of whole frequency band.
As another kind of implementation, the power spectrum signal of the whole frequency band of described structure comprises:
Step 21: according to the frequency range of high-rise appointment, determine the number K of scanning frequency
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth, and this pass band width is larger, and frequency points to be scanned is just fewer;
Hypothesis pass band width W is 20M in this example, and f_initial is 2300MHz, and f_end is 2400MHz, and then scanning frequency points K is 5;
Step 22: according to the frequency point scanning order, get successively each scanning frequency f, the yield value of AGC is set, switch to initial frequency,
Make f=f_initial+ (p-1) W+W/2, p is 307200Ts from 1 to K value successively for wireless frame data length of LTE system;
Step 23: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, initialization arrowband power array Norrow_Power passes through the optional network specific digit filter successively with the time domain data that receives, and measures the arrowband power Norrow_Power of i frequency
i, the value of i from 0 to
Described optional network specific digit filter bandwidht is the channel grid Δ f of system's regulation, and center frequency point is f_initial+ Δ f/2+i Δ f;
In the present embodiment, Δ f=100KHz, W=20M, Norrow_Power array length are 2000
Step 24: arrowband power array Norrow_Power is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
Step 25: switch to next scanning frequency, repeating step 23~step 25;
Step 26: by K structure, obtain the power spectrum signal of whole frequency band.
The described yield value that AGC is set of step 12 and step 22 comprises:
A1. be empirical value with the AGC gain value settings in advance, preferably be configured such that all undersaturated arbitrary values of each frequency receiver; In the present embodiment, described AGC initial gain is set to 40dB;
A2. initialization frequency AGC gain array AGC_Freq
k(1≤k≤K) is the full 0 array, and wherein K is scanning frequency points, in the present embodiment K=5;
A3. according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 radio frames time domain data;
A radio frames time domain data that A4. will receive is divided into the N piece, and every data length is L, calculates every blocks of data average power:
In the present embodiment, N=120, L=2560, i=1,2 ... N, I represent to receive the real part of time domain data, and Q represents to receive the imaginary part of time domain data;
A5. find out each blocks of data average power peak value, gain adjusts accordingly to AGC with this performance number;
A6. again receive a radio frames time domain data, repeating step A4, A5 are assigned to AGC_Freq until the satisfied AGC yield value is adjusted to satisfied preset value with described final AGC yield value
kMiddle correspondence position;
Preferably, the described AGC yield value that arranges, can also for:
B1. initialization frequency AGC gain array AGC_Freq
k(1≤k≤K) is the full 0 array, and wherein K is scanning frequency points, in the present embodiment K=5;
B2. be maximum in advance with the AGC gain value settings, according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 radio frames time domain data;
B3. measure this time domain data, obtain maximum power value P1;
B4. the automatic gain with the terminal receiver amplifier reduces a rank, remeasures the data that receive continuously on this frequency, obtains second maximum power value P2;
In the present embodiment, reduce a rank and refer to reduce 15dB;
B5. calculate the difference between P2 and the P1, and compare with the power difference threshold P that sets;
In the present embodiment, P=3dB;
If B6. P2-P1 is less than P, will gain to AGC with second maximum power value P2 adjusts accordingly; If P2-P1 is greater than thresholding P, then power measurement values returns to step B4 as the power measurement values P1=P2 first time for the second time.
If B7. AGC has been down to minimum rank, then get maximum corresponding to this frequency the AGC yield value is adjusted accordingly, deposit final AGC yield value in AGC gain array AGC_Freq
kCorrespondence position.
Preferably, step 13 comprises:
C1. calculate the screening N frequency points
Freq, computing formula is as follows
W
LTEBe bandwidth corresponding to the sample rate of LTE system, this example is 30.72M, and W is the filter passband bandwidth, and this example is 20M, and N_FFT is that FFT counts, and this example is 2048; Therefore calculate N
Freq=1333;
C2. to a radio frames receiving according to this N_FFT be length, be divided into M sub-block, be that the time domain data of N_FFT is made the FFT that N_FFT orders and obtained array FFTPoint (1:N_FFT) to each sub-block length, performance number corresponding to screening pass band width deposits in from FFTPoint
In the array, N_FFT=2048 in this example, M=150, the m value is from 1 to M=150, and k is scanning frequency sequence number, and screening mode is as follows:
C3. M sub-block frequency-region signal power spectrum superposeed and obtain power spectrum signal in the W bandwidth, namely
Preferably, step 15 comprises: the full frequency band power spectrum that constructs has KN
FreqIndividual sample point;
Preferably, described before with predetermined step-length and predetermined window power spectrum signal being scanned, the frequency band power after also comprising disabled frequency range in the power spectrum signal of whole frequency band and finishing frequency is set to zero.
Preferably, describedly with predetermined step-length and predetermined window power spectrum signal is scanned, predetermined window internal power value summation is obtained the broadband power array comprise:
D1. predetermined step-length is chosen near sample points d corresponding to the frequency interval of channel grid, this embodiment, and the LTE channel grid is 100KHz, the Whole frequency band power spectrum minimum interval that constructs
Know that by max (d|15d≤100) predetermined step-length is 6 sample points;
D2. predetermined window is generally chosen signal bandwidth, for the LTE system, because signal bandwidth is optional, usually is configured to 5M, 10M and 20M, therefore predetermined window can travel through 5M, the sample points that 10M and 20M are corresponding, namely choose respectively 300,600,1200 sample points as broadband power window Power_Window;
D3. take Power_Window/2 as initial frequency, d is step-length, and to full frequency band scanning, summation obtains each frequency broadband power array Freq_Power to the window internal power
i, owing to used the window of three different sizes to scan, therefore can obtain three groups of different broadband power array Freq_Power
i
Preferably, step D1 can also for:
Choose the sample points d near 2~3 times of correspondences of frequency interval of channel grid, take 2 times as example, the LTE channel grid is 100KHz, the Whole frequency band power spectrum minimum interval that constructs
By max (d|15d≤100*2) know that predetermined step-length is 12 sample points;
Preferably, described search broadband power array obtains the center frequency point position and comprises:
E1. find out three groups of Freq_Power
iIn every group of corresponding maximum, search broadband power value is greater than every group of maximum α performance number doubly in every group of maximum the right and left certain limit, and record its number, here α is 0.8, the hunting zone is each 75 sample point of front and back, think that the minimum group of number is the target group in three groups, find out value of frequency point corresponding to maximum in this group, think that this value of frequency point is the initial center frequency;
If the initial center frequency of E2. finding out not is the integral multiple of channel grid 100KHz, then appoints and get channel grid integral multiple frequency nearest about this frequency as the initial center frequency;
Preferably, can also proceed as follows for the center frequency point that obtains:
F1. at center frequency point the right and left take channel grid 100KHz as the interval, the frequency that takes a morsel carries out little sweeping, a small amount of frequency can be 3~10 in the present embodiment;
F2. described little sweeping namely receives time domain data according to conventional method at each frequency, by measuring its power, finds out frequency corresponding to power maximum, thinks center frequency point;
For the TD-SCDMA system, referring to Fig. 4, a subframe lengths is 6400chip, and the duration is 5ms.
The power spectrum signal of the whole frequency band of described structure comprises:
Step 61: according to the frequency range of high-rise appointment, determine the number K of scanning frequency
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth, and this pass band width is larger, and frequency points to be scanned is just fewer;
Hypothesis pass band width W is 1.28M in this example, and f_initial is 1880MHz, and f_end is 1920MHz, and then scanning frequency points K is 32;
Step 62: according to the frequency point scanning order, get successively each scanning frequency f, adjust the yield value of automatic gain control AGC, switch to initial frequency,
Make f=f_initial+ (p-1) W+W/2, p is 6400chip from 1 to K value successively for sub-frame data length of TD-SCDMA system;
Step 63: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, to a radio frames receiving according to this N_FFT be length, be divided into M sub-block, be that the time domain data of N_FFT is made the FFT that N_FFT is ordered to each sub-block length, and carry out frequency spectrum screening according to the receiver pass-band bandwidth, and obtaining sub-block frequency-region signal power spectrum, M sub-block frequency-region signal power spectrum superposeed obtains power spectrum signal in the W bandwidth
In the present embodiment, N_FFT=512, M=125;
Step 64: power spectrum signal is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
Step 65: switch to next scanning frequency, repeating step 63~step 65;
Step 66: by K structure, obtain the power spectrum signal of whole frequency band.
As another kind of implementation, the power spectrum signal of the whole frequency band of described structure comprises:
Step 71: according to the frequency range of high-rise appointment, determine the number K of scanning frequency
Wherein, f_initial is the initial frequency of the frequency range of high-rise appointment, and f_end is that the frequency range of high-rise appointment finishes frequency, and W is the receiver pass-band bandwidth, and this pass band width is larger, and frequency points to be scanned is just fewer;
Hypothesis pass band width W is 1.28M in this example, and f_initial is 1880MHz, and f_end is 1920MHz, and then scanning frequency points K is 32;
Step 72: according to the frequency point scanning order, get successively each scanning frequency f, adjust the yield value of automatic gain control AGC, switch to initial frequency,
Make f=f_initial+ (p-1) W+W/2, p is 6400chip from 1 to K value successively for sub-frame data length of TD-SCDMA system;
Step 73: according to the AGC yield value of adjusting, receive time domain data take a radio frames as unit, initialization arrowband power array Norrow_Power passes through the optional network specific digit filter successively with the time domain data that receives, and measures the arrowband power Norrow_Power of i frequency
i, the value of i from 0 to
Described optional network specific digit filter bandwidht is the channel grid Δ f of system's regulation, and center frequency point is f_initial+ Δ f/2+i Δ f;
In the present embodiment, Δ f=200KHz, W=1.28M, Norrow_Power array length are 6;
Step 74: arrowband power array Norrow_Power is carried out AGC eliminate operation, namely all power in the power spectrum be multiply by
AGC
kBe k AGC value corresponding to scanning frequency, k is value between 1 to K;
Step 75: switch to next scanning frequency, repeating step 73~step 75;
Step 76: by K structure, obtain the power spectrum signal of whole frequency band.
The described yield value that AGC is set of step 62 and step 72 comprises:
A1. be empirical value with the AGC gain value settings in advance, preferably be configured such that all undersaturated arbitrary values of each frequency receiver; In the present embodiment, described AGC initial gain is set to 40dB;
A2. initialization frequency AGC gain array AGC_Freq
k(1≤k≤K) is the full 0 array, and wherein K is scanning frequency points, in the present embodiment K=32;
A3. according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 sub-frame data;
A radio frames time domain data that a4. will receive is divided into the N piece, and every data length is L, calculates every blocks of data average power:
In the present embodiment, N=25, L=256, i=1,2 ... N, I represent to receive the real part of time domain data, and Q represents to receive the imaginary part of time domain data;
A5. find out each blocks of data average power peak value, gain adjusts accordingly to AGC with this performance number;
A6. again receive a radio frames time domain data, repeating step a4, a5 are assigned to AGC_Freq until the satisfied AGC yield value is adjusted to satisfied preset value with described final AGC yield value
kMiddle correspondence position;
Preferably, the described AGC yield value that arranges, can also for:
B1. initialization frequency AGC gain array AGC_Freq
k(1≤k≤K) is the full 0 array, and wherein K is scanning frequency points, in the present embodiment K=32;
B2. be maximum in advance with the AGC gain value settings, according to preset frequency interval scan order, sentence initial AGC value at each frequency and receive 1 radio frames time domain data;
B3. measure this time domain data, obtain maximum power value P1;
B4. the automatic gain with the terminal receiver amplifier reduces a rank, remeasures the data that receive continuously on this frequency, obtains second maximum power value P2;
In the present embodiment, reduce a rank and refer to reduce 15dB;
B5. calculate the difference between P2 and the P1, and compare with the power difference threshold P that sets;
In the present embodiment, P=3dB;
If b6. P2-P1 is less than P, will gain to AGC with second maximum power value P2 adjusts accordingly; If P2-P1 is greater than thresholding P, then power measurement values returns to step b4 as the power measurement values P1=P2 first time for the second time.
If b7. AGC has been down to minimum rank, then get maximum corresponding to this frequency the AGC yield value is adjusted accordingly, deposit final AGC yield value in AGC gain array AGC_Freq
kCorrespondence position.
Preferably, step 63 comprises:
C1. calculate the screening N frequency points
Freq, computing formula is as follows
W
LTEBe bandwidth corresponding to the sample rate of TD system, this example is 5.12M, and W is the filter passband bandwidth, and this example is 1.28M, and N_FFT is that FFT counts, and this example is 512; Therefore calculate N
Freq=128;
C2. to a sub-frame data receiving take N_FFT as length, be divided into M sub-block, be that the time domain data of N_FFT is made the FFT that N_FFT orders and obtained array FFTPoint (1:N_FFT) to each sub-block length, performance number corresponding to screening pass band width deposits in from FFTPoint
In the array,
N_FFT=512 in this example, M=125, the m value is from 1 to M=125, and k is scanning frequency sequence number, and screening mode is as follows:
C3. M sub-block frequency-region signal power spectrum superposeed and obtain power spectrum signal in the W bandwidth, namely
Preferably, step 65 comprises: the full frequency band power spectrum that constructs has KN
FreqIndividual sample point;
Preferably, described before with predetermined step-length and predetermined window power spectrum signal being scanned, the frequency band power after also comprising disabled frequency range in the power spectrum signal of whole frequency band and finishing frequency is set to zero.
Preferably, describedly with predetermined step-length and predetermined window power spectrum signal is scanned, predetermined window internal power value summation is obtained the broadband power array comprise:
D1. predetermined step-length is chosen near sample points d corresponding to the frequency interval of channel grid, and for this embodiment, the TD-SCDMA channel grid is 200KHz, the Whole frequency band power spectrum minimum interval that constructs
Know that by max (d|6.4d≤200) predetermined step-length is 31 sample points;
D2. predetermined window is generally chosen signal bandwidth, and for the TD-SCDMA system, signal bandwidth is 1.28M, and broadband power window Power_Window is 128;
D3. take Power_Window/2 as initial frequency, d is step-length, and full frequency band is scanned, and the window internal power is averaging obtains each frequency broadband power array Freq_Power
i
Preferably, steps d 1 can also for:
Choose the sample points d near 2~3 times of correspondences of frequency interval of channel grid, take 2 times as example, the TD-SCDMA channel grid is 200KHz, the Whole frequency band power spectrum minimum interval that constructs
By max (d|6.4d≤200*2) know that predetermined step-length is 62 sample points;
Preferably, described search broadband power array obtains the center frequency point position and comprises:
E1. find out Freq_Power
iIn maximum, find out value of frequency point corresponding to this maximum, think that this value of frequency point is the initial center frequency;
If the initial center frequency of e2. finding out not is the integral multiple of channel grid 200KHz, then appoints and get channel grid integral multiple frequency nearest about this frequency as the initial center frequency;
Preferably, can also proceed as follows for the center frequency point that obtains:
F1. at center frequency point the right and left take channel grid 200KHz as the interval, the frequency that takes a morsel carries out little sweeping, a small amount of frequency can be 3~10 in the present embodiment;
F2. described little sweeping namely receives time domain data according to conventional method at each frequency, by measuring its power, finds out frequency corresponding to power maximum, thinks center frequency point;
The above describes method of the present invention in detail, and for realizing that method of the present invention has multiple implement device, the below provides preferred embodiment, as shown in Figure 5.
Whole frequency band power spectrum signal constructing module is used for the interior power spectrum of frequency band range that tectonic system is stipulated;
The broadband power computing module is used for the full frequency band power spectrum to structure, scans with the predetermined window of predetermined step-length, and the window internal power is superposeed obtains full frequency band frequency point broadband power distribution array Freq_Power
i
The center frequency point search module is used for choosing Freq_Power
iFrequency corresponding to middle maximum power value is as the center frequency point position, frequency further also can take a morsel on the center frequency point both sides, according to conventional method, receive time domain data at each frequency, record its performance number, then to choose frequency corresponding to power maximum be final center frequency point and be sent to output unit.
Wherein, Whole frequency band power spectrum signal constructing module as shown in Figure 6, comprising:
The time domain data processing unit is used for calculating scanning frequency points K, with predetermined frequency interval, adjusts under the yield value of optimum AGC, receives time domain data take frame as unit;
The power spectrum structural unit, be used for the time domain data that certain frequency receives is divided into M sub-block, every blocks of data is carried out NFFT point FFT, and according to the receiver pass-band bandwidth, structure passband power spectrum constructs the full frequency band power spectrum by K frequency carried out same operation.
The power culling unit, the power setting that is used for the frequency range behind the disabled frequency range of full frequency band power spectrum (such as military frequency range and regulation frequency range frequency range in addition etc.) and the end frequency is zero.
The present invention is mainly by utilizing a small amount of time domain data that receives by FFT structure full frequency band power spectrum, only need in the power spectrum of structure, to search for corresponding frequency broadband power maximum and just can determine the center frequency point position, compared with prior art, the present invention only needs just can construct the full frequency band power spectrum by limited several frames, greatly reduced and searched frame time, thereby reached the blind purpose of sweeping of fast frequency point.
The present invention can be applicable to include but not limited to that TD-SCDMA system, LTE system are in all interior mobile communication system.
In several embodiment that the application provides, should be understood that disclosed apparatus and method can realize by another way.For example, device embodiment described above only is schematically, for example, the division of described module only is that a kind of logic function is divided, and during actual the realization other dividing mode can be arranged, but be not limited to above-mentioned division, as long as can realize corresponding function; In addition, the concrete title of each functional module also just for the ease of mutual differentiation, is not limited to protection scope of the present invention.For example a plurality of modules or assembly can in conjunction with or can be integrated into another system, or some features can ignore, or do not carry out.Another point, the shown or coupling each other discussed or direct-coupling or communication connection can be by some interfaces, indirect coupling or the communication connection of device or module can be electrically, machinery or other form.In addition, each functional module in each embodiment of the present invention can be integrated in the processing unit, also can be that the independent physics of modules exists, also can two or more module integrations in a unit.Above-mentioned integrated unit both can adopt the form of hardware to realize, also can adopt the form of SFU software functional unit to realize.
If described integrated unit is realized with the form of SFU software functional unit and during as independently production marketing or use, can be stored in the computer read/write memory medium.Based on such understanding, part or all or part of of this technical scheme that technical scheme of the present invention contributes to prior art in essence in other words can embody with the form of software product, this computer software product is stored in the storage medium, comprise that some instructions are with so that a computer equipment (can be personal computer, server, terminal equipment or the network equipment etc.) carry out all or part of step of the described method of each embodiment of the present invention.And aforesaid storage medium comprises: USB flash disk, portable hard drive, read-only memory (ROM, Read-Only Memory), the various media that can be program code stored such as random access memory (RAM, Random Access Memory), magnetic disc or CD.
One of ordinary skill in the art are clear and understanding obviously; for the method and apparatus of setting forth among each embodiment of the present invention, within the spirit and principles in the present invention all, any modification of doing; be equal to replacement, improvement etc., all should be included within protection scope of the present invention.