CN105791179B - Sampling frequency offset compensation device and method - Google Patents
Sampling frequency offset compensation device and method Download PDFInfo
- Publication number
- CN105791179B CN105791179B CN201410798482.XA CN201410798482A CN105791179B CN 105791179 B CN105791179 B CN 105791179B CN 201410798482 A CN201410798482 A CN 201410798482A CN 105791179 B CN105791179 B CN 105791179B
- Authority
- CN
- China
- Prior art keywords
- signal
- sampling frequency
- frequency offset
- domain
- loop
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Circuits Of Receivers In General (AREA)
Abstract
The embodiment of the invention discloses a kind of sampling frequency offset compensation device and methods.The sampling frequency offset compensation device includes: phaselocked loop, for generating offset estimation reference signal according to the pilot signal obtained from the time-domain signal；Sampling frequency offset estimation module, for estimating the sampling frequency offset signal of the time-domain signal according to the offset estimation reference signal；Sampling frequency offset compensating module carries out sampling frequency offset compensation to the time-domain signal for the sampling frequency offset according to estimated by the sampling frequency offset estimation module.Sampling frequency offset compensation device and method provided in an embodiment of the present invention realize the accurate compensation of the sampling frequency offset to stereo fm broadcast singal.
Description
Technical field
The present invention relates to field of communication technology more particularly to a kind of sampling frequency offset compensation devices and method.
Background technique
Although the utilization rate of digital display circuit radio receiver is improving, frequency modulation(PFM) (Frequency modulatin,
FM) receiver is still popular, and is come across in mobile phone and other electronic handsets more and more.It is received in numerous FM
In machine, stereo FM broadcast receiver is a kind of most commonly seen FM receiver.
For monophonic FM broadcast, transmitting signal only accounts for the frequency range of 30Hz to 15KHz, and not area is emitted in this frequency range
Divide the monophonic broadcasting signal of left and right acoustic channels.Referring to Fig. 1, in the frequency range of 30Hz to 15KHz, the letter of stereo FM broadcast transmitting
It number is left channel signals and right-channel signals and signal 11.Therefore stereophonic broadcasting letter is received according to mono receivers
Number, received reality is left and right acoustic channels and signal 11.Other than carrying above-mentioned and signal, stereo broadcasting signal further includes
The pilot signal 13 of 19KHz, and the difference signal 12 of carrying left channel signals and right-channel signals.The difference signal 12 is distributed in
It in the frequency range of 23KHz to 53KHz, and is double-sideband suppressed-carrier (Double side band suppressed
Carrier, DSBSC) signal.In receiver side, after receiving above-mentioned and signal 11 and difference signal 12, so that it may complete extensive
Restore the left channel signals and right-channel signals to begin.
The purpose of FM receiver is exactly the sound or music for providing a user high-fidelity.But in practical application, because producing
Usually there are some frequency departures in the temperature drift of the crystal oscillator of raw sample frequency and the influence of noise, sample frequency.
If sampling frequency deviation is too big, the sound or music of FM receiver output are possible to be distorted, and user experience is caused to deteriorate.So
And traditional FM receiver can not completely eliminate sampling frequency deviation, and user is caused to listen to the body of stereo FM broadcast
It tests very poor.
Summary of the invention
The embodiment of the present invention provides a kind of sampling frequency offset compensation device and method, to realize to stereo fm broadcast singal
Sampling frequency offset carry out accurate compensation.
In a first aspect, the embodiment of the invention provides a kind of sampling frequency offset compensation device, described device includes:
Phaselocked loop, for generating offset estimation reference signal according to the pilot signal obtained from the time-domain signal；
Sampling frequency offset estimation module, for estimating the sampling frequency of the time-domain signal according to the offset estimation reference signal
The number of believing one side only；
Sampling frequency offset compensating module, for the sampling frequency offset according to estimated by the sampling frequency offset estimation module to it is described when
Domain signal carries out sampling frequency offset compensation.
Second aspect, the embodiment of the invention also provides a kind of sampling frequency offset compensation methodes, which comprises
Offset estimation reference signal is generated according to the pilot signal obtained from received time-domain signal；
The sampling frequency offset signal of the time-domain signal is estimated according to the offset estimation reference signal；
Sampling frequency offset compensation is carried out to the time-domain signal according to the sampling frequency offset signal.
Sampling frequency offset compensation device and method provided in an embodiment of the present invention are believed according to the pilot tone obtained from time-domain signal
Number generate offset estimation reference signal, by the offset estimation reference signal of acquisition estimate the time-domain signal sampling frequency
The number of believing one side only, and the sampling frequency offset signal of the time-domain signal is compensated, it realizes and stereo fm broadcast singal is adopted
The accurate compensation of sample frequency deviation.
Detailed description of the invention
Fig. 1 is the spectrogram for the stereo FM broadcast modulation front signal that the prior art provides；
Fig. 2 is the structural schematic diagram for the sampling frequency offset compensation device that first embodiment of the invention provides；
Fig. 3 is the structural schematic diagram for the sampling frequency offset compensation device that second embodiment of the invention provides；
Fig. 4 is the spectrogram of bandpass filter in the sampling frequency offset compensation device of second embodiment of the invention offer；
Fig. 5 is the structural representation that time domain turns frequency domain module in the sampling frequency offset compensation device of second embodiment of the invention offer
Figure；
Fig. 6 is the structural schematic diagram of phaselocked loop in the sampling frequency offset compensation device of third embodiment of the invention offer；
Fig. 7 is the structural schematic diagram of low-pass filter in the sampling frequency offset compensation device of third embodiment of the invention offer；
Fig. 8 is the structural schematic diagram for the sampling frequency offset compensation device loop filter that third embodiment of the invention provides；
Fig. 9 is that the structure of sampling frequency offset estimation module in the sampling frequency offset compensation device of fourth embodiment of the invention offer is shown
It is intended to；
Figure 10 is the process of sampling frequency offset compensation method in the sampling frequency offset compensation device of sixth embodiment of the invention offer
Figure；
Figure 11 is the process of sampling frequency offset compensation method in the sampling frequency offset compensation device of seventh embodiment of the invention offer
Schematic diagram；
Figure 12 is the process signal for the sampling frequency offset compensation device frequency domain signal conversion that seventh embodiment of the invention provides
Figure；
Figure 13 is that the sampling frequency offset compensation device frequency deviation estimation reference signal that seventh embodiment of the invention provides generates
Flow diagram；
Figure 14 is the flow diagram for the sampling frequency offset estimation that seventh embodiment of the invention provides.
Specific embodiment
The present invention is described in further detail with reference to the accompanying drawings and examples.It is understood that this place is retouched
The specific embodiment stated is used only for explaining the present invention rather than limiting the invention.It also should be noted that in order to just
Only the parts related to the present invention are shown in description, attached drawing rather than entire infrastructure.
Sampling frequency offset compensation device provided in an embodiment of the present invention is applied in stereo FM broadcast receiver, for opposing
Sampling frequency offset in body sound FM broadcasting receiver is corrected.
First embodiment
Referring to fig. 2, the sampling frequency offset compensation device includes: phaselocked loop 21, sampling frequency offset estimation module 22 and sampling
Frequency offset compensation block 23.
The transmitting signal of stereo FM broadcast, that is, signal received by stereo FM broadcast receiver are a moulds
Quasi- signal.However, in order to be handled using transmitting signal of the general digital platform to the stereo FM broadcast, from
The stereo audio signal that high quality is demodulated in transmitting signal uses high in the radio-frequency front-end of the stereo radio receiver
The sampled signal of frequency samples received signal.After being sampled to received signal, when discrete
Between domain received signal is handled.
But due to factors such as interference, noises, the sampled signal that the signal received is sampled frequency frequent occurrence
Partially, it causes the result sampled to the signal received inaccurate, and then is difficult to the extensive of from the signal received high quality
It appears again stereo audio signal.Technical solution provided in this embodiment is used to solve above-mentioned technical problem.
The phaselocked loop 21 is used to generate offset estimation reference signal according to the pilot signal obtained from time-domain signal.
The pilot signal is the reception signal from the stereo FM broadcast, that is, extracted in time-domain signal
Pilot signal.The pilot signal is a simple signal.Specifically, the frequency of the pilot signal is 19kHz.
Referring to Fig. 1, believe in the original signal before the stereo FM broadcast modulation comprising the pilot tone that a frequency is 19kHz
Numbers 13.The purpose that the pilot signal 13 is added in the signal before the modulation is to assist realizing to left channel signals and the right side
The demodulation of difference signal 12 between sound channel signal.After obtaining the corresponding frequency-region signal of the time-domain signal, bandpass filter is utilized
22 extract the pilot signal 13 from the frequency-region signal.
Estimate specifically, the phaselocked loop 21 generates frequency deviation and carrying out frequency and Phase Tracking to the pilot signal of input
Count reference signal.Identical as the pilot signal, the offset estimation reference signal is also a simple signal.Ordinary circumstance
Under, the frequency of the offset estimation reference signal is higher than the frequency of the pilot signal.Also, the offset estimation reference signal
Phase it is synchronous with the holding of the phase of the pilot signal.
Further, the phaselocked loop 21 includes multiplier, low-pass filter, the first loop filter and numerical control oscillation
Device.
The sampling frequency offset estimation module 22 is used to estimate the time-domain signal according to the offset estimation reference signal
Sampling frequency offset signal.
Since holding is synchronous between the phase and the phase of the pilot signal of the offset estimation reference signal, so can
The sampling frequency offset of the time-domain signal is estimated with the half period starting point using the offset estimation reference signal.
The sampling frequency offset compensating module 23 is for sampling the time-domain signal according to the sampling frequency offset signal
Frequency deviation compensation.
Specifically, the sampling frequency offset compensating module 23 frequency of the sampling according to estimated by the sampling frequency offset estimation module 22
Sampling time point is redefined to the time-domain signal partially, to carry out sampling frequency offset compensation to the time-domain signal.
The present embodiment is by generating offset estimation reference signal according to the pilot signal of extraction using phaselocked loop, using described
Sampling frequency offset estimation module estimates the sampling frequency offset signal of the time-domain signal, Yi Jili according to the offset estimation reference signal
The sampling frequency offset of the time-domain signal is compensated according to the sampling frequency offset signal with the sampling frequency offset compensating module, from
And realize the accurate compensation of the sampling frequency offset to the time-domain signal.
Second embodiment
The present embodiment provides a kind of technical solution of sampling frequency offset compensation device on the basis of the above embodiments.In addition to
Other than phaselocked loop 33, sampling frequency offset estimation module 35 and sampling frequency offset compensating module 36, which includes: that time domain turns frequency
Domain module 31, bandpass filter 32 and sample synchronization module 34.
Referring to Fig. 3, the sampling frequency offset compensation device includes: that time domain turns frequency domain module 31, bandpass filter 32, phaselocked loop
33, sample synchronization module 34, sampling frequency offset estimation module 35 and sampling frequency offset compensating module 36.
The time domain turns frequency domain module 31 for the time-domain signal of input to be converted to frequency-region signal.
The time domain turns time-domain signal of the frequency domain module 31 for receiving stereo FM broadcast receiver, that is, vertical
The transmitting signal of body sound FM broadcast is converted to frequency-region signal.
In general, the transmitting signal of the stereo FM broadcast after sampling has the form of formula (1):
Wherein, T is sampling period, ω0For the angular frequency of the transmitting signal of stereo FM broadcast, θ0For stereo FM broadcast
Transmitting signal phase, f (kT) be the audio signal modulated, that is, stereo FM broadcast modulate before signal, KfFor
Summation coefficient, φFMIt (kT) is the transmitting signal of the stereo FM broadcast.
It converts by the time domain of the transmitting signal to the stereo FM broadcast to frequency domain to get frequency-region signal f has been arrived
(kT)。
Preferably, (Coordinate can be calculated by executing Coordinate Rotation Digital to the time-domain signal
Rotational digital computer, CORDIC) and phase difference and obtain frequency-region signal.
The bandpass filter 32 from the frequency-region signal for obtaining the pilot signal of setpoint frequency.
Fig. 4 shows the spectral characteristic of the bandpass filter.It referring to fig. 4, is the band logical filter near 19kHz frequency point
The passband of wave device 32, other portions of the spectrum are the inhibition band of the bandpass filter 32.By the bandpass filter 32 it
Afterwards, other frequency contents for including in the frequency-region signal are filtered out, under the pilot signal that only frequency is 19kHz has been retained
Come.Preferably, the bandpass filter 32 has narrow-band characteristic.
It should be noted that the 19kHz, refers to the corresponding analog signal before sampling to the signal received
Frequency.
The phaselocked loop 33 is used to generate offset estimation reference signal according to the pilot signal of input.
The sample synchronization module 34 is used to obtain the half period starting point of the offset estimation reference signal.
Preferably, the sample and collected offset estimation in real time for the offset estimation reference signal that calculating prestores can be passed through
Cross-correlation function between reference signal obtains the half period starting point of the offset estimation reference signal.
Specifically, the half period sample of the offset estimation reference signal can be stored in memory.When producing
After stating offset estimation reference signal, the half period sample and the offset estimation for calculating the offset estimation reference signal are referred to
Cross-correlation function between signal is finally referred to using the cross-correlation function value maximum time point as the offset estimation
The half period starting point of signal.
The half period that the sampling frequency offset estimation module 35 is used to be obtained according to the sample synchronization module 34 originates
The sampling frequency offset signal of time-domain signal described in point estimation.
The sampling frequency offset compensating module 36 is used for the sampling frequency offset according to estimated by the sampling frequency offset estimation module 35
Sampling frequency offset compensation is carried out to the time-domain signal.
The present embodiment by sampling frequency offset compensation device be arranged time domain turn frequency domain module, bandpass filter, phaselocked loop,
Sample synchronization module, sampling frequency offset estimation module and sampling frequency offset compensating module, extract pilot signal, root from frequency-region signal
Offset estimation reference signal is generated according to the pilot signal, estimates the time-domain signal using the offset estimation reference signal
Sampling frequency offset finally compensates the sampling frequency offset, to carry out standard to the sampling frequency offset of stereo FM broadcast singal
True compensation effectively reduces the reception bit error rate of stereo FM broadcast signal.
Illustratively, referring to Fig. 5, it includes: phase acquiring unit 51 and difference unit 52 that the time domain, which turns frequency domain module 31,.
The phase acquiring unit 51 is used to obtain the phase of the time-domain signal according to arc tangent solving method or CORDIC method
Position.
The difference unit 52 is used to carry out difference to the phase, to obtain the frequency-region signal.
3rd embodiment
The present embodiment provides a kind of technical solution of phaselocked loop on the basis of the above embodiments, the technical solution packet
It includes: multiplier 61, low-pass filter 63, the first loop filter 64, accumulator 65 and digital controlled oscillator 66.
Referring to Fig. 6, the pilot signal that the multiplier 61 is used to will acquire is multiplied with the reference signal of same frequency.
The reference signal with pilot signal with frequency differs the phase of pi/2 with the pilot signal.If the pilot tone letter
Number be 19kHz sinusoidal signal, then the reference signal be 19kHz cosine signal.The pilot signal and the reference are believed
Number be multiplied relationship provided by formula (2):
Wherein, ω is the angular frequency of the pilot signal, and α is the phase of the pilot signal, and β is the reference signal
Phase, T are the sampling interval duration of the pilot signal and the reference signal, and sin (ω kT+ α) is that the described of kT moment is led
Frequency signal, cos (ω kT+ β) are the reference signal at kT moment, and θ (kT) is pilot signal described in the kT moment and the reference
Signal after signal multiplication.
By formula (2) it is known that θ (kT) includes that the signal that an angular frequency is 2 ω and one do not change over time
Direct current signal.The signal that angular frequency is 2 ω is known as high-frequency signal, and the direct current signal is known as low frequency signal.
The low-pass filter 63 is used to filter out the high-frequency signal in the output signal of the multiplier.
The passband of the low-pass filter 63 is in the low frequency part of frequency spectrum, and inhibits band in the radio-frequency head of frequency spectrum
Point, therefore the high-frequency signal in the output signal of the multiplier can be filtered out.
It should be noted that frequency of the cutoff frequency of the low-pass filter 63 not above the high-frequency signal,
It is exactly the corresponding frequency of 2 ω of angular frequency in formula (2).
First loop filter 64 is used to carry out loop filtering to the filtered signal of the low-pass filter 63, obtains
To low frequency signal.
In order to eliminate the influence of interference signal and noise in 21 output signal of phaselocked loop, to the low-pass filtering
The filtered signal of device 63 carries out loop filtering.
The accumulator 65 is for adding up to the low frequency signal, when accumulation result value reaches threshold value, generates touching
It signals.
Specifically, the totalizing step is provided by formula (3):
In formula (3), step_value is the totalizing step of the accumulator 65, and fd is the frequency of the pilot signal,
Fs is the sample frequency of the time-domain signal.
The digital controlled oscillator 66 is used to generate the offset estimation reference signal according to the trigger signal.
When the digital controlled oscillator 66 receives the trigger signal that the accumulator 65 exports, the digital controlled oscillator 66
Export the offset estimation reference signal.Specifically, the digital controlled oscillator 66, when receiving the trigger signal, output has
There is the offset estimation reference signal of cosine form.
Preferably, the phaselocked loop 33 further includes twice of amplifier 62.Twice of amplifier 62 is used for from institute
It states the signal that inputs in multiplier 61 and carries out twice of amplification, be in 61 output signal of multiplier described in compensation (3) 1/2
Number.
The pilot signal is multiplied by the present embodiment by multiplier with the reference signal of same frequency, utilizes low-pass filter pair
Signal after multiplication carries out low-pass filtering, loop filtering is carried out to the signal Jing Guo low-pass filtering using loop filter, to ring
The low frequency signal generated after the filtering of road adds up, and exports offset estimation with reference to letter when accumulation result reaches totalizing step
Number, the Phase Tracking to the pilot signal is completed, the offset estimation reference signal with accurate phase is generated.
Illustratively, the low-pass filter 63 further comprises: the first multiplier 71, first adder 72, second multiply
Musical instruments used in a Buddhist or Taoist mass 73, second adder 74 and the first delay unit 75.
Referring to Fig. 7, first multiplier 71 be used for by the input signal of the low-pass filter 63 with first control because
Son is multiplied, and the consequential signal of multiplication is input to the second adder 74.Wherein, the value of first controlling elements exists
Between 0 to 1.The value variation of first controlling elements can be used for controlling the bandwidth of the low-pass filter 63.
The first adder 72 is used for the result that first controlling elements are added with 1 signal of logic, and will add up
It exports to second multiplier 73.
Second multiplier 73 is used for the low-pass filtering after the output valve and delay of the first adder 72
The output valve of device 63 is multiplied, and second adder 74 described in the readout by multiplication
The second adder 74 is used for the output result phase of first multiplier 71 and second multiplier 73
Add, obtains the output valve of the low-pass filter 63.
First delay unit 75 is used to carry out the output valve of the low-pass filter 63 delay process, and will delay
The output valve of the low-pass filter 63 afterwards is exported to second multiplier 73.
Illustratively, first loop filter 64 further comprises: third multiplier 81, third adder 82 and
Second delay unit 83.
Referring to Fig. 8, the third multiplier 81 is used for the input signal of first loop filter 64 and the second control
Fac-tor processed, and the result of multiplication is exported to third adder 82.Wherein, the value of second controlling elements is 0 to 1
Between.Also, second controlling elements are used to control the computational accuracy and convergence rate of the loop filter 64.
The multiplying signal that the third adder 82 is used to input from the third multiplier 81 and the institute by delay
The output signal for stating the first loop filter 64 is added, to generate the output signal of first loop filter 64.
Second delay unit 83 is used to carry out delay process to the output signal of first loop filter 64, and
The output signal of first loop filter 64 after delay is exported to the third adder 82.
3rd embodiment
The present embodiment provides a kind of technical solution of sampling frequency offset estimation module on the basis of the above embodiments.
Referring to Fig. 9, which includes: that Timing Error Detection unit 91, the second loop filter 92 and timing miss
Poor processing unit 93.
The Timing Error Detection unit 91 is specifically used for the detection time domain and turns the received time-domain signal of frequency domain module 31
Timing error, obtain signal of timing error.
Specifically, the Timing Error Detection unit 91 determines the timing error of the time-domain signal according to formula (4):
E [k]={ y_f [kT+T/2]-y_f [(k-1) T+T/2] } × y_f [kT] (4)
Wherein, y_f [kT+T/2] is the offset estimation reference signal at kT+T/2 moment, and y_f [(k-1) T+T/2] is (k-1)
The offset estimation reference signal at T+T/2 moment, y_f [kT] are the offset estimation reference signal at kT moment, and E [kT] is the kT moment
The signal of timing error.
Second loop filter 92 is used to carry out loop filtering to the signal of timing error.
Since there may be errors for the signal of timing error that is detected by the Timing Error Detection unit 91, so needing pair
The signal of timing error is smoothed.Specifically, being pair to the mode that the signal of timing error is smoothed
The signal of timing error carries out loop filtering.
Illustratively, second loop filter 92 carries out loop filtering to the signal of timing error according to formula (5).
E_loop [k]=E_loop [k-1]+G × E [k] (5)
Wherein, E [k] is the signal of timing error at k moment, and G is gain coefficient, and E_loop [k] is described the second of k moment
Loop filter 92 carries out the signal that loop rate filters to the signal of timing error, and E_loop [k-1] is the k-1 moment
Second loop filter 92 carries out the signal that loop filtering obtains to the signal of timing error.
The timing error processing unit 93 is used to export to the signal progress reverse phase and clipping that loop filtering obtains is carried out
The sampling frequency offset signal estimated according to the offset estimation reference signal.
Specifically, the timing error processing unit 93 may include the reverse phase processing executed according to formula (6), and to upper
State the amplitude limiting processing for the consequential signal for asking difference to handle.
E_out=C-E_loop (6)
In formula (6), C is constant, and E_loop is that second loop filter 92 carries out the signal of timing error
The signal that loop filtering obtains, E_out are the consequential signal for asking difference to handle.It is understood that by being shown in formula (6)
Ask poor calculating, since C is constant, opposite in phase between obtained E_out signal and E-loop signal, namely complete pair
Carry out the reverse phase processing for the signal that loop filtering obtains.
The present embodiment is by calculating the timing error of the time-domain signal according to the offset estimation reference signal, to obtaining
Signal of timing error carry out loop filtering, and further reverse phase and clipping are carried out to the signal after loop filtering, obtained
Accurate estimation to the sampling frequency offset of the time-domain signal.
Fourth embodiment
The present embodiment provides a kind of technical solution of sampling frequency offset compensating module on the basis of the above embodiments.At this
In technical solution, the sampling frequency offset compensating module realizes the sampling frequency to the time-domain signal in the way of filtering interpolation
Inclined compensation.
Preferably, the sampling frequency offset compensating module is an interpolation filter.The interpolation filter is right according to formula (7)
The sampling frequency offset of the time-domain signal compensates.
Y_out (m)=y (m)+p_f × [y (m+1)-y (m)] (7)
Wherein, y_out (m) is the time-domain sample signal at the m moment of differential filtering device output, y (m) and y (m+1)
The time-domain sample signal that the respectively described differential filtering device inputs at m moment and m+1 moment, and p_f is the sampling frequency
The fractional part for the sampling frequency offset signal that inclined estimation module obtains.
Further, the time-domain sample signal is the time of the sampling time point sampled to the time-domain signal.
The present embodiment sampling frequency offset signal according to estimated by the sampling frequency offset estimation module to the time-domain signal into
Row interpolation filtering, so that the sample frequency to the time-domain signal has carried out accurate compensation.
5th embodiment
Sampling frequency offset compensation method provided in this embodiment has above-mentioned sampling frequency offset compensation device to realize.
Referring to Figure 10, the sampling frequency offset compensation method includes: operation 101 to 103.
Operation 101 generates offset estimation reference signal according to the pilot signal obtained from the time-domain signal.
The pilot signal is included in a simple signal in the time-domain signal, is mainly used for auxiliary to the left side
Difference signal between sound channel signal and the right-channel signals is demodulated.Preferably, using phaselocked loop to the pilot signal
Phase Tracking is carried out, to generate the offset estimation reference signal.
Operation 102, the sampling frequency offset signal of the time-domain signal is estimated according to the offset estimation reference signal.
Preferably, the time domain can be estimated according to the half period starting point of the offset estimation reference signal of acquisition
The sampling frequency offset signal of signal.
Operation 103 carries out sampling frequency offset compensation to the time-domain signal according to the sampling frequency offset signal.
After obtaining the sampling frequency offset signal, according to the sampling frequency offset signal to the sampling frequency offset of the time-domain signal
It compensates.Preferably, the time-domain signal is sampled by redefining the sampling time point of the time-domain signal
Frequency deviation compensation.
The present embodiment, which passes through, generates offset estimation reference signal, root according to the pilot signal obtained from the time-domain signal
The sampling frequency offset signal of the time-domain signal is estimated according to the offset estimation reference signal, and according to the sampling frequency offset signal
Sampling frequency offset compensation is carried out to the time-domain signal, to realize to the sampling frequency offset of the time-domain signal of stereo FM broadcast
Accurate compensation.
5th embodiment
The present embodiment gives the another technical solution of sampling frequency offset compensation method based on above-described embodiment.This
In technical solution, before generating the offset estimation reference signal, received time-domain signal is converted into frequency-region signal；From institute
State the pilot signal that setpoint frequency is obtained in frequency-region signal；After generating the offset estimation reference signal, adopted described in estimation
Before sample frequency offset signal, the half period starting point of the offset estimation reference signal is obtained；Then referred to according to the offset estimation
Signal estimates that the sampling frequency offset signal of the time-domain signal includes: to originate time-domain signal described in point estimation according to the half period
Sampling frequency offset signal.
Referring to Figure 11, the sampling frequency offset compensation method includes: to operate 111 to operation 116.
Operation 111, is converted to frequency-region signal for received time-domain signal.
It is time-domain signal that the stereo FM receiver, which receives,.It, will be described after receiving above-mentioned time-domain signal
Time-domain signal is converted to frequency-region signal.
Operation 112 obtains the pilot signal of setpoint frequency from the frequency-region signal.
The single frequency pilot for being 19kHz comprising a frequency in the frequency-region signal.Obtain the frequency-region signal with
Afterwards, the pilot signal is obtained from the frequency-region signal.Preferably, institute is obtained from the frequency-region signal by bandpass filtering
State pilot signal.
Operation 113 generates offset estimation reference signal according to the pilot signal of acquisition.
After obtaining the pilot signal, offset estimation reference signal is generated according to the pilot signal.Preferably, it utilizes
Phaselocked loop carries out Phase Tracking to the pilot signal, to generate the offset estimation reference signal.
Operation 114, obtains the half period starting point of the offset estimation reference signal.
Specifically, the half period sample and the offset estimation by calculating the offset estimation reference signal prestored are with reference to letter
Number cross-correlation function, and the time point that the cross-correlation function is maximized is as the half of the offset estimation reference signal
Period starting point.
Operation 115 originates the sampling frequency offset signal of time-domain signal described in point estimation according to the half period.
Operation 116 carries out sampling frequency offset compensation to the time-domain signal according to the sampling frequency offset.
Illustratively, referring to Figure 12, it includes: operation 121 and operation that received time-domain signal, which is converted to frequency-region signal,
122。
Operation 121 calculates CORDIC method according to arc tangent solving method or Coordinate Rotation Digital and obtains the time-domain signal
Phase.
Operation 122 carries out difference to the phase, to obtain the frequency-region signal.
Illustratively, referring to Figure 13, generating offset estimation reference signal according to the pilot signal of acquisition includes:
Operation 131, the pilot signal that will acquire is multiplied with the reference signal of same frequency.
Operation 132, filters out the high-frequency signal in the output signal of multiplication.
Operation 133 carries out loop filtering to filtered signal, obtains low frequency signal.
Operation 134, adds up to the low frequency signal, when accumulation result value reaches threshold value, generates trigger signal.
Operation 135 generates the offset estimation reference signal according to the trigger signal.
Illustratively, referring to Figure 14, the sampling frequency offset for originating time-domain signal described in point estimation according to the half period includes:
Operation 141, detects the timing error of received time-domain signal, obtains signal of timing error.
Operation 142 carries out loop filtering to the signal of timing error.
Operation 143 carries out reverse phase and clipping to the signal that loop filtering obtains is carried out, and output is joined according to the offset estimation
Examine the sampling frequency offset signal of signal estimation.
The present embodiment obtains setting frequency by the way that received time-domain signal is converted to frequency-region signal from the frequency-region signal
The pilot signal of rate generates offset estimation reference signal according to the pilot signal of acquisition, obtains the offset estimation reference signal
Half period starting point, the sampling frequency offset of time-domain signal described in point estimation is originated according to the half period, frequently according to the sampling
Sampling frequency offset compensation is carried out to the time-domain signal partially, realizes the accurate benefit to the sampling frequency offset of stereo fm broadcast singal
It repays.
Note that the above is only a better embodiment of the present invention and the applied technical principle.It will be appreciated by those skilled in the art that
The invention is not limited to the specific embodiments described herein, be able to carry out for a person skilled in the art it is various it is apparent variation,
It readjusts and substitutes without departing from protection scope of the present invention.Therefore, although being carried out by above embodiments to the present invention
It is described in further detail, but the present invention is not limited to the above embodiments only, without departing from the inventive concept, also
It may include more other equivalent embodiments, and the scope of the invention is determined by the scope of the appended claims.
Claims (12)
1. a kind of sampling frequency offset compensation device characterized by comprising time domain turn frequency domain module, bandpass filter, phaselocked loop,
Sample synchronization module, sampling frequency offset estimation module and sampling frequency offset compensating module, in which:
The time domain turns frequency domain module, for received time-domain signal to be converted to frequency-region signal；
The bandpass filter turns frequency domain module with the time domain and is connected, for obtaining setpoint frequency from the frequency-region signal
Pilot signal；
The phaselocked loop is connected with the bandpass filter, and the pilot signal for being obtained according to the bandpass filter generates frequency
Estimation reference signal partially；
The sample synchronization module is connected with the phaselocked loop, the offset estimation reference signal for will receive, and prestores
Offset estimation reference signal sample carries out cross-correlation, and by cross correlation value maximum time point, refers to as the offset estimation
The half period starting point of signal；
The sampling frequency offset estimation module is connected with the phaselocked loop and the sample synchronization module respectively, comprising:
Timing Error Detection unit, input terminal input time-domain signal, for detect the time domain turn frequency domain module it is received when
The timing error of domain signal, obtains signal of timing error；Second loop filter is connected with the Timing Error Detection unit,
For carrying out loop filtering to the signal of timing error；Timing error processing unit is connected with second loop filter,
For being referred to according to processing result and the offset estimation to the signal progress reverse phase and amplitude limiting processing that loop filtering obtains is carried out
Signal estimates sampling frequency offset signal；
The sampling frequency offset compensating module turns frequency domain module phase with the sampling frequency offset estimation module and the time domain respectively
Even, the input terminal of the sampling frequency offset compensating module inputs time-domain signal, for being estimated according to the sampling frequency offset estimation module
The sampling frequency offset signal of meter carries out sampling frequency offset compensation to the time-domain signal.
2. sampling frequency offset compensation device according to claim 1, which is characterized in that the time domain turns frequency domain module and includes:
Phase acquiring unit obtains the time domain letter for calculating CORDIC method according to arc tangent solving method or Coordinate Rotation Digital
Number phase；
Difference unit, for carrying out difference to the phase, to obtain the frequency-region signal.
3. sampling frequency offset compensation device according to claim 1, which is characterized in that the phaselocked loop includes:
Multiplier, the pilot signal for will acquire are multiplied with the reference signal of same frequency；
Low-pass filter, the high-frequency signal in output signal for filtering out the multiplier；
First loop filter obtains low frequency signal for carrying out loop filtering to the filtered signal of the low-pass filter；
Accumulator, when accumulation result value reaches threshold value, generates trigger signal for adding up to the low frequency signal；
Digital controlled oscillator, for generating the offset estimation reference signal according to the trigger signal.
4. sampling frequency offset compensation device according to claim 3, which is characterized in that the totalizing step of the accumulator are as follows:
Wherein, step_value is the totalizing step of the accumulator, fdFor the frequency of the pilot signal, fsFor the time domain
The sample frequency of signal.
5. sampling frequency offset compensation device according to claim 1, which is characterized in that the Timing Error Detection unit obtains
The signal of timing error are as follows:
E [k]={ y_f [kT+T/2]-y_f [(k-1) T+T/2] } × y_f [kT]
Wherein, y_f [kT+T/2] is the offset estimation reference signal at kT+T/2 moment, and y_f [(k-1) T+T/2] is (k-1) T+
The offset estimation reference signal at T/2 moment, y_f [kT] are the offset estimation reference signal at kT moment, and E [k] is the described of k moment
Signal of timing error.
6. sampling frequency offset compensation device according to claim 1, which is characterized in that second loop filter is to described
Signal of timing error carries out the signal that loop filtering obtains are as follows:
E_loop [k]=E_loop [k-1]+G × E [k]
Wherein, E [k] is the signal of timing error at k moment, and G is gain coefficient, and E_loop [k] is second loop at k moment
Filter carries out the signal that filters of loop rate to the signal of timing error, and E_loop [k-1] is described the of k-1 moment
Second Ring Road filter carries out the signal that loop filtering obtains to the signal of timing error.
7. sampling frequency offset compensation device according to claim 1, which is characterized in that the timing error processing unit output
The sampling frequency offset signal are as follows:
E_out=C-E_loop
Wherein, C is constant, and E_loop is that second loop filter obtains signal of timing error progress loop filtering
Signal, E_out be the sampling frequency offset signal.
8. sampling frequency offset compensation device according to claim 1, which is characterized in that the sampling frequency offset compensating module is slotting
Value filter.
9. sampling frequency offset compensation device according to claim 8, which is characterized in that the interpolation filter output signal
Are as follows:
Y_out [m]=y [m]+p_f × { y [m+1]-y [m] }
Wherein, p_f is the fractional part of the sampling frequency offset signal, and y [m] is the time-domain signal at m moment, when y [m+1] is m+1
The time-domain signal at quarter, y_out [m] are the output signal of the interpolation filter.
10. a kind of sampling frequency offset compensation method characterized by comprising
Received time-domain signal is converted into frequency-region signal；
The pilot signal of setpoint frequency is obtained from the frequency-region signal；
Offset estimation reference signal is generated according to the pilot signal；
The offset estimation reference signal that will be received carries out cross-correlation with the offset estimation reference signal sample prestored, and will be mutual
Correlation maximum time point, the half period starting point as the offset estimation reference signal；
The timing error for detecting received time-domain signal, obtains signal of timing error；
Loop filtering is carried out to the signal of timing error；
Reverse phase and amplitude limiting processing are carried out to the signal that loop filtering obtains is carried out, is referred to according to processing result and the offset estimation
Signal estimates sampling frequency offset signal；
Sampling frequency offset compensation is carried out to the time-domain signal according to the sampling frequency offset signal.
11. sampling frequency offset compensation method according to claim 10, which is characterized in that be converted to received time-domain signal
Frequency-region signal includes:
The phase that CORDIC method obtains the time-domain signal is calculated according to arc tangent solving method or Coordinate Rotation Digital；
Difference is carried out to the phase, to obtain the frequency-region signal.
12. sampling frequency offset compensation method according to claim 10, which is characterized in that generate frequency according to the pilot signal
Estimate that reference signal includes: partially
The pilot signal that will acquire is multiplied with the reference signal of same frequency；
Filter out the high-frequency signal in the output signal of multiplication；
Loop filtering is carried out to filtered signal, obtains low frequency signal；
It adds up to the low frequency signal, when accumulation result value reaches threshold value, generates trigger signal；
The offset estimation reference signal is generated according to the trigger signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410798482.XA CN105791179B (en) | 2014-12-18 | 2014-12-18 | Sampling frequency offset compensation device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410798482.XA CN105791179B (en) | 2014-12-18 | 2014-12-18 | Sampling frequency offset compensation device and method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105791179A CN105791179A (en) | 2016-07-20 |
| CN105791179B true CN105791179B (en) | 2019-03-29 |
Family
ID=56385838
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410798482.XA Active CN105791179B (en) | 2014-12-18 | 2014-12-18 | Sampling frequency offset compensation device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105791179B (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106507020B (en) * | 2016-11-24 | 2023-08-25 | 杭州雄迈集成电路技术股份有限公司 | Coaxial self-adaptive simulation high-definition transmission anti-attenuation device and method based on differential compensation |
| CN106685869B (en) * | 2017-01-19 | 2020-04-14 | 京信通信系统（中国）有限公司 | Frequency offset compensation method and related device |
| CN108632005B (en) * | 2017-03-24 | 2023-12-15 | 华为技术有限公司 | Reference signal transmission method, device and system |
| CN107135182B (en) * | 2017-04-10 | 2020-06-30 | 上海顺久电子科技有限公司 | Frequency offset calculation method and device for frequency modulation signal |
| CA3173393A1 (en) * | 2017-09-20 | 2019-03-28 | Christian Rohde | Adaptive timing synchronization for reception for bursty and continuous signals |
| CN110445739B (en) * | 2019-08-13 | 2022-02-01 | 北京智芯微电子科技有限公司 | Method and device for compensating sampling frequency offset |
| CN112995078B (en) * | 2019-12-13 | 2022-11-15 | 丽水青达科技合伙企业(有限合伙) | Frequency offset compensation algorithm of OFDMA uplink |
| CN112565129A (en) * | 2020-12-08 | 2021-03-26 | 上海擎昆信息科技有限公司 | Frequency offset compensation method and system |
| CN114531327B (en) * | 2022-01-26 | 2022-11-04 | 小唐科技（上海）有限公司 | Frequency deviation self-tracking device |
| CN114878910B (en) * | 2022-07-13 | 2022-10-28 | 中国科学技术大学 | High-precision frequency measurement method, device and system based on beat sampling |
| CN116094889A (en) * | 2022-12-30 | 2023-05-09 | 安徽聆思智能科技有限公司 | Stable demodulation frequency tracking method and device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7949319B2 (en) * | 2007-03-22 | 2011-05-24 | Silicon Laboratories Inc. | Receiver architectures for digital radio broadcasts and associated methods |
| JP5267874B2 (en) * | 2009-07-24 | 2013-08-21 | ソニー株式会社 | Signal processing apparatus and signal processing method |
| CN102752249B (en) * | 2011-04-20 | 2015-05-27 | 上海炬力集成电路设计有限公司 | Signal detection device and method |
| CN102185653B (en) * | 2011-04-26 | 2015-10-28 | 北京大学 | Based on the relevant radio telecommunicaltion system of frequency stabilized carbon dioxide laser, method and receiver |
| CN103220252A (en) * | 2013-04-10 | 2013-07-24 | 安徽华东光电技术研究所 | Coding orthogonal frequency division multiplexing wireless signal receiving and processing device and processing method thereof |
| CN104168224B (en) * | 2013-05-20 | 2017-07-28 | 普天信息技术研究院有限公司 | Offset estimation and compensation method |
-
2014
- 2014-12-18 CN CN201410798482.XA patent/CN105791179B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN105791179A (en) | 2016-07-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105791179B (en) | Sampling frequency offset compensation device and method | |
| RU2260908C2 (en) | Method and device for reducing noise in receivers for frequency-modulated in-band digital channel audio-casting | |
| US11296739B2 (en) | Noise suppression device, noise suppression method, and reception device and reception method using same | |
| JP2001044868A (en) | Broadcast signal receiving device | |
| CN104639190A (en) | Analog front-end system of frequency modulation receiver and processing method thereof | |
| CN102957642A (en) | Radio data receiving system and receiving method thereof | |
| JP2005295378A (en) | Ultrasonic digital communication device | |
| US8406717B1 (en) | Digital FM stereo receiver architecture to recover carrier information based on stereo or mono signals | |
| EP1081870A1 (en) | Detection of noise in a frequency demodulated FM-audio broadcast signal | |
| US8472906B1 (en) | Systems and methods for recovery of a sub-carrier signal from a stereophonic multiplexed signal | |
| CN105229928A (en) | The method estimated for signal quality and control and circuit | |
| TWI617202B (en) | Stereo-Phonic FM Receiver and Separation Method for Dual Sound Channels | |
| WO2016075878A1 (en) | Signal processing device and signal processing method | |
| CN104618276B (en) | Carrier frequency bias estimation and system in a kind of FM receiver | |
| US8064858B1 (en) | Digital carrier-recovery scheme for FM stereo detection | |
| JP4281260B2 (en) | FM demodulator and receiver | |
| JP6611057B2 (en) | Received signal processing apparatus, received signal processing method, and program | |
| JP2006033074A (en) | Ofdm demodulator | |
| JP5274353B2 (en) | Modulation specification estimation circuit, modulation scheme identification device, and modulation specification estimation method | |
| JP4245243B2 (en) | FM radio receiver signal processing circuit | |
| TW201040942A (en) | Method and apparatus for multiplex signal decoding | |
| JP2005064617A (en) | Multipath distortion elimination filter | |
| JP2006279173A (en) | Terrestrial digital broadcasting receiver and terrestrial digital broadcasting receiving program | |
| JP5020275B2 (en) | Receiving apparatus and baseband signal processing method | |
| JP3839009B2 (en) | Multipath noise detection method and detection apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |