CN100493224C - Frequency correcting method and device - Google Patents
Frequency correcting method and device Download PDFInfo
- Publication number
- CN100493224C CN100493224C CNB2006100326302A CN200610032630A CN100493224C CN 100493224 C CN100493224 C CN 100493224C CN B2006100326302 A CNB2006100326302 A CN B2006100326302A CN 200610032630 A CN200610032630 A CN 200610032630A CN 100493224 C CN100493224 C CN 100493224C
- Authority
- CN
- China
- Prior art keywords
- signal
- frequency
- multipath
- correction
- module
- 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
- 238000000034 method Methods 0.000 title claims abstract description 32
- 238000012937 correction Methods 0.000 claims abstract description 189
- 238000012545 processing Methods 0.000 claims description 39
- 238000005562 fading Methods 0.000 claims description 34
- 238000005259 measurement Methods 0.000 claims description 26
- 230000007423 decrease Effects 0.000 claims description 23
- 238000001914 filtration Methods 0.000 claims description 7
- 230000010355 oscillation Effects 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 7
- 230000008878 coupling Effects 0.000 claims description 6
- 238000010168 coupling process Methods 0.000 claims description 6
- 238000005859 coupling reaction Methods 0.000 claims description 6
- 230000001915 proofreading effect Effects 0.000 claims description 6
- 239000013078 crystal Substances 0.000 claims description 4
- 230000005540 biological transmission Effects 0.000 abstract description 8
- 238000001514 detection method Methods 0.000 abstract description 3
- 230000007274 generation of a signal involved in cell-cell signaling Effects 0.000 abstract 1
- 230000001427 coherent effect Effects 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005194 fractionation Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 238000010295 mobile communication Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Landscapes
- Mobile Radio Communication Systems (AREA)
Abstract
The present invention provides frequency correction method and device. It contains Utilizing receiving all cell signal frequency offset estimation, uniform proceeding calibration to received carrier frequency, independent estimating each cell signal residual frequency offset, through feed forward frequency correction ensuring each cell signal demodulation and detection performance; also through coherence length shorter cell searching, fast selecting demodulation cell participate carrier frequency calibrating signal generation and residual frequency offset forward correcting, quick adjusting carrier frequency in switching or cell updating, to make it more approaching most strong service cell transmission frequency, ensuring metric switching or cell updating accuracy, reducing up-down going transmitted signal power, system interference; cell searching to obtain higher SNR cell, measuring CPICH signal intensity.
Description
Technical field
The present invention relates to wireless communication field, particularly in communication network, the method and apparatus that portable terminal is proofreaied and correct frequency shift (FS).
Background technology
In the wireless communication system, for guaranteeing the continuous covering and the reception of radio transmission signal, user terminal (UE) will communicate simultaneously with different base station, perhaps by measuring and switching, select best server cell to communicate.
For example, in the WCDMA system, during moving, UE keeps and the communicating by letter of network, be in the overlapping region that two base station signals cover, system will arrange UE to carry out soft handover, UE communicates with two base stations by two air interlace channel simultaneously, and downstream signal uses different pseudo-random bits scramblings, and UE handles by RAKE and receives these two signals; UE is in the overlapping region that two base station signals cover, and also has a kind of switchover policy, and UE connects same frequency or the alien-frequency district that is directly switch to another base station from a base station, is called direct-cut operation; Handoff procedure can also carry out between the same base different districts, is called More Soft Handoff.
UE is in login state, when not arranged professional the connection with any base station, UE is by the measurement of down public guide frequency channel (CPICH) signal strength signal intensity, reside in a best server cell, and constantly search for and measure the signal of neighbor cell, when UE moves to other cell coverage area,, best server cell is upgraded by signal measurement.
When UE is in the Traffic Channel connection status, at first communicate with a base station, also to constantly search for and measure adjacent cell signal, measurement result is reported network side, when the adjacent cell signal of measuring surpasses handoff threshold, the Traffic Channel that adds the adjacent area is RAKE merges, perhaps switch to adjacent sub-district and receive, improve down-link reception performance.
Though be the reception of homogenous frequency signal, moving of UE will influence its receive frequency to the different base station signal, also having a kind of situation is that the base station works long hours and may influence its clock stability, and synchronizing signal can not in time be calibrated, and the downstream signal frequencies that different base station sends is also variant.Both of these case is below roughly described:
Propagation between base station and the UE mostly is intracardiac signal greatly, and UE moves causing the frequency of its received signal to be moved, and is called Doppler frequency shift.The frequency deviation that UE receives downstream signal is
F is a carrier frequency, and C is a propagation velocity of electromagnetic wave, and v is a moving velocity of terminal, and θ is the angle of direction of relative movement and signal propagation direction.For example, for the translational speed of carrier frequency and the 300km/h of 2GHz, maximum frequency deviation may be 556Hz.
Fig. 1 has represented that high-speed mobile environment UE receives the situation of two base station signal frequencies, does not consider the stability of base station clock, and the transmission signal frequency of base station 1 and base station 2 all is f
0, UE is away from base station 1, and it is f that UE receives base station 1 frequency reception signal
0-f
d, UE is to base station 2 fast moving, and is f to the receive frequency of base station 2
0+ f
dAlso there is certain difference in the clock of base station itself, if the set relatively carrier frequency of the frequency of two base stations self has an opposite deviation, the frequency difference of UE received signal will be bigger.
Fig. 2 has then represented another kind of situation, although agreement has certain requirement to the base station clock precision, the base station works long hours, and there is certain shake in clock accuracy, possibly can't provide the stable clock synchronizing signal to calibrate in the special networking scheme, the transmission signal frequency f of base station 1 and base station 2
1And f
2Has very big-difference.
When UE is in a plurality of base station signals overlay area, must guarantee that receiving different base station sends the demodulation of Traffic Channel or the measurement of common signal channel intensity.Under the prior art condition, the WCDMA system adopts the detection mode of coherent demodulation to improve receptivity, require receiving terminal the demodulation carrier wave must with the carrier wave of received signal with homophase frequently, UE has only the middle radio-frequency channel of a reception, can't distinguish the received signal of same carrier different districts, when there is certain frequency deviation in the different base station received signal, separating of UE is in harmonious proportion measurement performance has proposed challenge.
Consider the design cost of UE, the precision of its crystal oscillator and long-time stability all have certain restriction, need to come automatic locking system to send the frequency of signal by AFC (automatic frequency control), and the frequency of locking sent upward signal as the reference benchmark, required precision to UE locking downstream signal frequencies among the WCDMA is 0.1PPM, i.e. 200Hz.
Under present technical conditions, the technical scheme module map that addresses this problem as shown in Figure 3.301 links and 302 links are unified middle radio-frequency channel, produce the carrier frequency that UE receives by 310 links; 303 links are by the transmission of the known CPICH signal of different districts, by mating the relevant multipath information that obtains the different districts signal; 304 links are finished the separated in synchronization of each sub-district multipath signal; 305 links and 306 links are carried out multi-path demodulation to CPICH channel and the DPCH channel that receives different districts respectively, and the DPCH channel here is an example, comprises all possible down channel demodulation in the real system; 305 links are exported the decline information of multipath channel simultaneously, removing provides the DPCH channel to do each footpath decline correction, be outside the channel estimating, do frequency offset estimating for simultaneously 309 links, 307 links and 308 links have been represented the decline information of the multipath channel of two sub-district acquisitions, and actual conditions may have only 1 or more sub-districts; 309 links obtain comprehensive frequency deviation information by cross product frequency discrimination, the filtering of front and back symbol decline information, the cotangent of negating, and export correspondent frequency control information again, and the radio-frequency (RF) local oscillator of 310 links is adjusted; Channel estimating, RAKE that 311 links and 312 links are finished each physical channel merge and decoding, and RAKE comprises the soft merging that the DPCH channel may exist in merging.
303 links are measured each sub-district CPICH channel received signal intensity, i.e. RSCP and Ec/Io (signal to noise ratio of forward pilot) according to the energy information of each sub-district CPICH channel multi-path searching among the figure.
When adopting said method to carry out frequency correction, be easy to generate following problem:
1, when having only radio frequency AFC comprehensively to lock all base station down received signals of reception, roughly the same with two base station signal strength is example, the reception carrier frequency of UE locking among Fig. 1
Should be near f
0, f is all arranged for the received signal of base station in the base band data 1 and base station 2
dFixedly frequency deviation, the coherent demodulation decreased performance of back link.
When 2, if UE moves to Zone switched that two base station signals cover from receiving base station 1 signal, the UE radio-frequency channel downstream frequency f of locking base station 1 earlier in the technical scheme one
0-f
d, the received signal of base station 2 has 2 * f in the base band data
dFrequency deviation, the CPICH measurement performance of 303 links descends, 305 links and 309 can very fast adding base station 2 signal separate the mediation frequency calibration, when having only the received signal power of base station 2 stronger, just may carry out demodulation by the information of 305 links adding base station 2, by the closed loop adjustment of 309 links, 310 links and 301 links, progressively frequency lock is arrived f
0About, because the delay that power requirement increases and measures causes switching and the best cell updating delay, the increase of uplink and downlink signals transmitted power also causes power system capacity to descend.Signal covers the general situation of intensity, also may cause UE to switch unsuccessful and call drop.
3, coherent demodulation can improve the detection performance, in the existing method, 303 links are carried out CPICH and are measured, consider that UE adapts to the different radio environment, because may there be big frequency deviation in the high-speed mobile environment base band data, limited the selection of coherence length when measuring, the measurement performance that makes non-high velocity environment use descends.
Summary of the invention
In order to solve the above-mentioned problems in the prior art, the present invention proposes a kind of method and apparatus that skew is proofreaied and correct to the mobile communications network medium frequency.
The present invention proposes a kind of auto frequency control apparatus, comprise multipath fading estimation module, multipath cross product frequency discriminator block and frequency correction information output module;
Described frequency correction information output module is made up of all cell frequency control information output modules and at least one single subdistrict frequency correction information output module;
Multipath fading estimation module receive channel decline information, produce multipath channel decline information, multipath cross product frequency discriminator block is carried out the cross product frequency discrimination to multipath channel decline information and is handled, all cell frequency control information output modules and single subdistrict frequency correction information output module, the result handles to the cross product frequency discrimination, all cell frequency control information output module output frequency input signal correction feedback signals, single subdistrict frequency correction module message output module output multipath signal frequency deviation correction feed-forward signal.
Described all cell frequency control information output modules merge module, low pass filter, frequency offset calculation module and correction signal amplitude adjusting module by all sub-district multipath frequency discrimination information and form, be used for the cross product frequency discrimination result in each footpath, all sub-districts is merged, filtering, asks frequency deviation, export unified frequency input signal correction feedback signal.
Described single subdistrict frequency correction information output module merges module, low pass filter, frequency offset calculation module and digitally controlled crystal oscillator by single subdistrict multipath frequency discrimination information and forms, be used to merge the frequency discrimination result of this sub-district receiving multipath signals, by filtering, ask frequency deviation, export the multipath signal frequency deviation correction feed-forward signal of this sub-district.
A kind of frequency correction equipment, radiofrequency signal processing module, multipath signal demodulation module and multipath signal merge module in comprising, also comprise multipath signal correction module, and aforesaid auto frequency control apparatus;
Described auto frequency control apparatus, the channel fading information that the receiving multipath signals demodulation module sends, and according to channel fading information output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal;
Radiofrequency signal processing module in described according to the frequency input signal correction feedback signal of described auto frequency control apparatus output, is adjusted the frequency of input signal; Described multipath signal correction module according to the multipath signal frequency deviation correction feed-forward signal of described auto frequency control apparatus output, is adjusted the fixedly frequency deviation of multipath signal; Described multipath signal merges module, and just each sub-district multipath signal through overcorrect carries out the RAKE merging.
In the such scheme, described middle radiofrequency signal processing module comprises radiofrequency signal receiver module, radio-frequency (RF) local oscillator output module and intermediate-freuqncy signal output module; The radio-frequency (RF) local oscillator output module carries out demodulation to the radiofrequency signal that the radio frequency signal receiving module receives, and by intermediate-freuqncy signal output module output baseband signal.
In the such scheme, described middle radiofrequency signal processing module is proofreaied and correct the radio frequency local oscillation signal according to the frequency input signal correction feedback signal that receives; Or, baseband signal is proofreaied and correct.
In the said frequencies calibration equipment, can further increase each district pilots channel measurement module, the pilot signal after frequency correction and the decline correction is measured.
A kind of subscriber terminal equipment, at least comprise that signal transmitting and receiving module and signal processing module is characterized in that, also comprise frequency correction equipment, described frequency correction equipment comprises: middle radiofrequency signal processing module, multipath signal demodulation module, multipath signal merge module, multipath signal correction module, and aforesaid auto frequency control apparatus.The received signal that frequency correction equipment received signal transceiver module sends, demodulated received signal, obtain channel fading information, according to channel fading information input signal and multipath signal are carried out frequency correction, and the multipath signal after the frequency correction merged, signal after merging is sent to signal processing module, and the signal of signal processing module after to the merging that receives handled; Auto frequency control apparatus, the channel fading information that the receiving multipath signals demodulation module sends, and according to channel fading information output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal; Middle radiofrequency signal processing module according to the frequency input signal correction feedback signal of auto frequency control apparatus output, is adjusted the frequency of input signal; Multipath signal correction module according to the multipath signal frequency deviation correction feed-forward signal of auto frequency control apparatus output, is adjusted the fixedly frequency deviation of multipath signal; Multipath signal merges module, will carry out RAKE through each sub-district multipath signal of overcorrect and merge.
In frequency correction equipment, further increase each district pilots channel measurement module, the pilot signal of frequency correction equipment output is measured, and measurement data is sent to the signal transmitting and receiving module.
The present invention also proposes a kind of method of frequency correction, it is characterized in that, in subscriber terminal equipment, may further comprise the steps: the channel fading information of a, the output of auto frequency control apparatus receiving multipath signals demodulation module, according to channel fading information, output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal, described auto frequency control apparatus is aforementioned auto frequency control apparatus; The frequency input signal correction feedback signal that b, middle radiofrequency signal processing module are exported according to described auto frequency control apparatus, the frequency of adjustment input signal; Multipath signal correction module is according to the multipath signal frequency deviation correction feed-forward signal of described auto frequency control apparatus output, the frequency deviation of proofreading and correct the multipath signal of multipath signal demodulation module output.In the such scheme, before the described step a, the multipath signal demodulation module obtains the multipath information of each cell signal at first by Multipath searching, determines the demodulation sub-district; Described Multipath searching mates relevant by the mode that reduces the coupling coherence length, select the demodulation sub-district fast.
In the such scheme, comprise further among the described step a that described auto frequency control apparatus selects the multipath signal of the highest sub-district of signal to noise ratio to produce frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal; Or the multipath signal of selecting signal to noise ratio to surpass the sub-district of predetermined value produces frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal.
In the such scheme, described step b further comprises:
Middle radiofrequency signal processing module is demodulated to baseband signal by the radio-frequency (RF) local oscillator signal with the radiofrequency signal that receives;
Middle radiofrequency signal processing module is proofreaied and correct the radio frequency local oscillation signal according to the frequency input signal correction feedback signal that receives; Or, baseband signal is proofreaied and correct.
After the step b, can also comprise step b1: will be through the multipath signal of frequency correction, carry out each cell channel and estimate, to the multipath signal correction that declines.After the step b1, can also comprise step b2: the pilot channel of the multipath signal that decline is proofreaied and correct to process is measured, and metrical information is reported network side.
In the such scheme, the measurement of the pilot channel of the described multipath signal that decline is proofreaied and correct to process can increase the coupling coherence length and mate relevant.
The method and apparatus of the frequency correction that the present invention proposes, by to the received signal with demodulation after multipath signal proofread and correct, when having guaranteed that high-speed mobile environment and different base station clock have than big-difference, the separating to be in harmonious proportion of each cell signal detected performance; Select the demodulation sub-district to participate in the generation of carrier frequency calibrating signal simultaneously fast, and the forward direction of residual frequency departure is proofreaied and correct, when making UE switching or cell update, the rapid adjustment carrier frequency, make itself and the transmission frequency of strong Serving cell is more approaching, guarantee switching or cell update promptness and the accuracy measured to reduce the power that up-downgoing sends signal, reduce system interference, solved problems of the prior art.
Description of drawings
Fig. 1 has represented that high-speed mobile environment UE receives the situation of two base station signal frequencies;
Fig. 2 has represented to produce owing to the clock reason situation of frequency deviation;
Fig. 3 prior art solves the schematic diagram of frequency offset issues;
Fig. 4 general plotting block diagram of the present invention;
Fig. 5 is the auto frequency control apparatus structured flowchart;
Fig. 6 is the frequency correction equipment structured flowchart;
Fig. 7 is a kind of structured flowchart of subscriber terminal equipment;
Fig. 8 is the flow chart of frequency calibrating method;
Fig. 9 is the application block diagram of medium frequency bearing calibration of the present invention.
Execution mode
For making the purpose, technical solutions and advantages of the present invention clearer, by the following examples, and, the present invention is described in further detail with reference to accompanying drawing.
The present invention proposes a kind of method and apparatus of frequency correction, when there is certain frequency shift (FS) in the signal of different base station, can effectively carry out frequency correction, guarantee the normal reception of signal, improve switching and the demodulation performance of having reined in UE.
General plotting of the present invention as shown in Figure 4.401 links are Cell searching stages, when user terminal is in login state or be in the Traffic Channel connection status, can search for always and measure adjacent cell signal, measure the SNR information of adjacent cell signal; 402 links determine whether this sub-district is joined in the demodulation sub-district according to the SNR value that 401 link Cell searchings measure, and the sub-district of having only the SNR value to surpass certain thresholding just joins the demodulation sub-district, otherwise the directly not Cell searching output of its signal strength measurement; 403 links are analyzed the frequency decline information of all demodulation sub-districts, export frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal respectively; 404 links are carried out frequency correction respectively to the multipath signal of input signal and output, simultaneously frequency shift (FS) are proofreaied and correct from two aspects like this, have guaranteed the minimum of frequency shift (FS), simultaneously the multipath signal after the frequency correction are merged.
Based on above-mentioned design, the present invention at first proposes a kind of auto frequency control apparatus as shown in Figure 5, comprise multipath fading estimation module, multipath cross product frequency discriminator block and frequency correction information output module, the frequency correction information output module is made up of all cell frequency control information output modules and at least one single subdistrict frequency correction information output module.All cell frequency control information output module output frequency input signal correction feedback signals; Single subdistrict frequency correction module message output module output multipath signal frequency deviation correction feed-forward signal.
All cell frequency control information output modules merge module, low pass filter, frequency offset calculation module and correction signal amplitude adjusting module by all sub-district multipath frequency discrimination information and form; Single subdistrict frequency correction information output module merges module, low pass filter, frequency offset calculation module and digitally controlled crystal oscillator by single subdistrict multipath frequency discrimination information and forms.
The multipath fading estimation module receives the channel fading information of each demodulation sub-district, carries out multipath according to channel fading information and estimates, generates multipath channel decline information, and this information is sent to multipath cross product frequency discriminator block, carries out multipath cross product frequency discrimination; All cell frequency control information output modules merge, filtering, ask frequency deviation the cross product frequency discrimination result in each footpath, all sub-districts, export unified frequency input signal correction feedback signal; And single subdistrict frequency correction information output module merges the frequency discrimination result of this sub-district receiving multipath signals respectively, by filtering, ask frequency deviation, and output multipath signal frequency deviation correction signal separately.Usually, UE can test the signal of a plurality of sub-districts simultaneously, determine that a plurality of sub-districts are the demodulation sub-district, therefore in the frequency correction information output module, we can add the multipath signal frequency deviation correction feed-forward information that a plurality of single subdistrict frequency correction module are exported a plurality of sub-districts.
On the basis that proposes above-mentioned auto frequency control apparatus, the invention allows for a kind of frequency correction equipment, its structured flowchart is as shown in Figure 6.This frequency correction equipment has also comprised auto frequency control apparatus and multipath signal correction module except radiofrequency signal processing module, multipath signal demodulation module and multipath signal in comprising merge the module.
Auto frequency control apparatus is connected with middle radiofrequency signal processing module, multipath signal demodulation module and multipath signal correction module; Multipath signal correction module merges module with multipath signal demodulation module and multipath signal and is connected.
Middle radiofrequency signal processing module is made up of radiofrequency signal receiver module, radio-frequency (RF) local oscillator module and intermediate-freuqncy signal output module; The multipath signal demodulation module is made up of Multipath searching module, multipath signal separation module and channel demodulation module.
Auto frequency control apparatus is exported frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal respectively according to channel fading information, as previously described, no longer repeats here.
When user terminal passes through the antenna received RF signal, the radiofrequency signal that radiofrequency signal receiver module reception antenna in the middle radiofrequency signal processing module receives, and the radio-frequency (RF) local oscillator signal that adopts the radio-frequency (RF) local oscillator module to provide carries out demodulation, and send signal to the intermediate-freuqncy signal output module, export the intermediate frequency baseband signal.Here, the radio-frequency (RF) local oscillator module can utilize the frequency input signal correction feedback signal of auto frequency control apparatus output that the local frequency of the clock generating of user terminal is adjusted, can guarantee when skew takes place the radiofrequency signal that receives, use corresponding local frequency to carry out demodulation, the frequency shift (FS) minimum of the signal after the demodulation; The input signal demodulation module also can utilize the intermediate frequency baseband signal of frequency input signal correction feedback signal pair signal output module output frequently to proofread and correct simultaneously, guarantees the less frequency shift (FS) of intermediate frequency baseband signal.
Middle radiofrequency signal processing module output intermediate frequency baseband signal is to the multipath signal demodulation module, Multipath searching module in the multipath signal demodulation module is searched for and is measured the intermediate frequency baseband signal that receives, obtain the multipath information of each sub-district multipath signal, measure the signal to noise ratio of each cell channel, determine the demodulation sub-district according to the signal to noise ratio of each sub-district; The multipath information of the demodulation sub-district that the multipath signal separation module records according to the Multipath searching module, the signal of each sub-district of receiving is carried out the separated in synchronization of multipath signal, multipath signal with each sub-district after the separated in synchronization sends to the channel demodulation module simultaneously, the channel demodulation module utilizes spreading code that the multipath signal of each sub-district is carried out despreading, multipath signal after the despreading is sent to multipath signal correction module, simultaneously channel fading information is sent to auto frequency control apparatus.
Auto frequency control apparatus receive channel decline information is according to channel fading information output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal.
Multipath signal correction module receiving multipath signals frequency deviation correction feed-forward signal, multipath signal to the demodulation sub-district after the despreading carries out frequency correction, can carry out the correction of frequency to the received signal for the second time like this, thereby guarantee the minimum of multipath signal frequency shift (FS).
Simultaneously because in the transmission course of signal, various declines can appear, here we have further increased the multipath channel estimation module in frequency correction equipment, to the correction that declines of the multipath signal of multipath signal correction module output, can under the situation that guarantees the frequency shift (FS) minimum, further guarantee the distortion minimum of signal; Multipath signal after proofreading and correct is sent to multipath signal merge module.
User terminal need report the information of each sub-district to network side, as signal to noise ratio etc., we increase each district pilots channel measurement module after the multipath channel estimation module, pilot signal to each sub-district is measured, owing to passed through feedback compensation and forward feedback correction to received signal, can adopt more that long symbol is relevant to be added, obtain more reliable SNR.Each district pilots channel measurement module reports network side with metrical information.
Multipath signal merges module and will merge through the multipath signal of each sub-district of overcorrect, obtains primary signal.
The invention allows for a kind of subscriber terminal equipment, as shown in Figure 7.This subscriber terminal equipment comprises signal transmitting and receiving module, signal processing module and power module at least, and its difference is pointed out to be, increases a frequency correction equipment, and the radiofrequency signal that receives is carried out frequency correction, improves the reception of signal.
The received signal that described frequency correction equipment received signal transceiver module sends, this received signal of demodulation, obtain channel fading information, according to channel fading information input signal and multipath signal are carried out frequency correction, and the multipath signal after the frequency correction merged, the signal after merging is sent to signal processing module.
In frequency correction equipment, increase simultaneously the multipath channel estimation module,, the multipath signal after proofreading and correct is sent to multipath signal merging module corrections that decline of the multipath signal of multipath signal correction module output.In frequency correction equipment, further increase each district pilots channel measurement module, the pilot signal after correction and the channel estimating is measured, and measurement data is sent to the signal transmitting and receiving module.The signal transmitting and receiving module sends to network side with metrical information.The multipath signal of signal processing module after to the merging that receives detects or deciphers, convert the multipath signal after merging to original signal that transmitting terminal sends, this signal can be a voice signal, also can be packet data signals, to this present invention without limits.Power module is responsible for providing power supply to each module of user terminal.Utilize above-mentioned user terminal, can better receive wireless signal, improve the reception of signal.
The present invention has further also proposed a kind of method of frequency correction, as shown in Figure 8, utilizes this method, can reduce the frequency shift (FS) of received signal, guarantees the quality of received signal.
This method may further comprise the steps:
After middle radiofrequency signal processing module receives radiofrequency signal, radiofrequency signal is carried out demodulation, obtain the intermediate frequency baseband signal, and the intermediate frequency baseband signal sent to the multipath signal demodulation module, the multipath signal demodulation module carries out Multipath searching, the intermediate frequency baseband signal that receives is measured,, this sub-district is joined in the demodulation sub-district when the signal to noise ratio of the sub-district of the being surveyed time greater than certain value; Multipath signal to the demodulation sub-district carries out separated in synchronization and spread spectrum demodulation simultaneously, obtains the decline information of each sub-district multipath channel.Here can to adopt the mode that reduces the coupling coherence length to mate relevant for Multipath searching, selects the demodulation sub-district fast.
Step 802, auto frequency control apparatus receive channel decline information, output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal.
The automatic frequency correction module receives the channel fading information that the multipath signal demodulation module sends, and exports frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal respectively according to channel fading information; The signal of its output will be used for carrying out with multipath signal to received signal the correction of frequency.
Here auto frequency control apparatus can select each footpath signal of the highest sub-district of signal to noise ratio to produce frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal, and the institute that also can select signal to noise ratio to surpass the sub-district of predetermined value produces frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal through signal.
Middle radiofrequency signal processing module has two kinds according to the method that frequency input signal correction feedback signal carries out the frequency correction of received signal:
1, middle radiofrequency signal processing module is used for frequency input signal correction feedback signal the radio frequency local oscillation signal is adjusted, when skew takes place in the frequency of the radiofrequency signal that receives, middle radiofrequency signal processing module is adjusted the radio frequency local oscillation signal according to frequency input signal correction feedback signal, make it better demodulation radiofrequency signal, reduce the frequency shift (FS) of received signal.
2, middle radiofrequency signal processing module is used the radio-frequency (RF) local oscillator signal of fixed frequency, radiofrequency signal is carried out demodulation, but frequency input signal correction feedback signal is used for the intermediate frequency baseband signal that obtains after the demodulation radiofrequency signal is adjusted, reduces the frequency shift (FS) of received signal.
Multipath signal correction module is according to the multipath signal feed-forward signal of rectifying a deviation, the frequency shift (FS) of proofreading and correct the multipath signal of multipath signal demodulation module output.
After above-mentioned steps, in order further to improve the precision of received signal, we can also increase following steps:
Step 804 is carried out each cell channel and is estimated, to the multipath signal correction that declines.
Owing in the process of signal transmission, not only can be offset the also signal fadeout that may cause by occurrence frequency owing to the reason of channel fading.Here we can come the multipath signal correction that declines is reduced the distortion of signal by the mode of channel estimating.
When carrying out channel estimating, can adopt smoothly carrying out of longer time simultaneously.
Step 805 to carrying out the measurement of the pilot signal of each sub-district through the multipath signal of overcorrect, reports network side with metrical information.
After Cell searching obtains the high sub-district of SNR, participate in separating after the mediation frequency correction, carry out the signal of pilot channel again, the SNR that obtains than Cell searching is many reliably, and each cell signal exists residual frequency departure to influence measurement performance during Cell searching.Here measure and report, can improve the precision of measurement.
The measurement of the pilot channel of the multipath signal that decline is proofreaied and correct to process here can be mated relevant by the mode that increases the coupling coherence length.
Multipath signal to each sub-district merges, and obtains original signal.
Utilize this method can reduce the frequency shift (FS) of received signal, the receptivity of raising wireless signal is improved the quality of communicating by letter greatly.
For principle of the present invention and application further are described, we carry out functional fractionation with each module, are example with two demodulation sub-district A and B below, further specify the present invention, as shown in Figure 9.It is pointed out that the present invention does not limit two demodulation sub-districts.
901 links, received RF signal; 902 links produce the intermediate frequency baseband signal; 903 links, for carrying out Multipath searching, the signal strength signal intensity of measurement pilot is determined the demodulation sub-district, obtains multipath information; 904 links, according to the multipath information that 903 links produce, the multipath signal of many demodulation sub-district carries out separated in synchronization; 905 links and 906 links are carried out two district pilots channel CPICH respectively and are separated mediation DPCH channel demodulation, demodulation process comprise the down channel that might receive, if there are not data to send, the DPCH channel may not exist yet, and delivers to 907 automatic frequency control AFC link during the channel fading information of same of A and B two sub-districts; The 907AFC link, it is finished output frequency input signal correction feedback signal (917 link) simultaneously and exports A, B sub-district multipath signal frequency deviation correction feed-forward signal (915,916 link); 908 links utilize frequency input signal correction feedback signal that the radio frequency local oscillation signal is adjusted, and also can carry out frequency correction to the intermediate frequency baseband signal here certainly, are preferred situation here; 909 and 910 links utilize respectively 915,916 links the feedforward deviation correcting signal multipath signal is carried out frequency correction, make each cell signal no longer include residual frequency departure; 911 links, that carries out that channel estimating in the channel estimating coherent demodulation can adopt the longer time smoothly improves performance; 912,913 links are measured A, B sub-district CPICH channel respectively, obtain more accurate SNR value, can adopt the more relevant processing of long symbol here; 914 links after correction and channel estimating, are carried out RAKE merging to each footpath signals of two sub-districts.
The method and apparatus of the frequency correction that the present invention proposes, utilize the frequency offset estimating that receives all cell signals, unified carrier frequency to reception is calibrated, estimate the residual frequency departure of each cell signal separately, proofread and correct by feed-back frequency, when high-speed mobile environment and different base station clock have than big-difference, guarantee that the mediation of separating of each cell signal detects performance; Simultaneously by the short Cell searching of coherence length, select the demodulation sub-district to participate in the generation of carrier frequency calibrating signal fast, and the forward direction of residual frequency departure is proofreaied and correct, when making UE switching or cell update, the rapid adjustment carrier frequency, make itself and the transmission frequency of strong Serving cell is more approaching, guarantee switching or cell update promptness and the accuracy measured, reduce the power that up-downgoing sends signal, reduce system interference; Cell searching obtains the higher sub-district of SNR, carries out the measurement of CPICH signal strength signal intensity after the participation demodulation again, and is more more reliable than the SNR that Cell searching obtains, and solved problems of the prior art.
Above-described specific embodiment; purpose of the present invention, technical scheme and beneficial effect are further described; institute is understood that; the above only is specific embodiments of the invention; be not limited to the present invention; within the spirit and principles in the present invention all, any modification of being made, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (16)
1, a kind of auto frequency control apparatus comprises multipath fading estimation module, multipath cross product frequency discriminator block and frequency correction information output module, it is characterized in that,
Described frequency correction information output module is made up of all cell frequency control information output modules and at least one single subdistrict frequency correction information output module;
Multipath fading estimation module receive channel decline information, produce multipath channel decline information, multipath cross product frequency discriminator block is carried out the cross product frequency discrimination to multipath channel decline information and is handled, all cell frequency control information output modules and single subdistrict frequency correction information output module, the result handles to the cross product frequency discrimination, all cell frequency control information output module output frequency input signal correction feedback signals, single subdistrict frequency correction module message output module output multipath signal frequency deviation correction feed-forward signal.
2, a kind of auto frequency control apparatus as claimed in claim 1, it is characterized in that, described all cell frequency control information output modules merge module, low pass filter, frequency offset calculation module and correction signal amplitude adjusting module by all sub-district multipath frequency discrimination information and form, be used for the cross product frequency discrimination result in each footpath, all sub-districts is merged, filtering, asks frequency deviation, export unified frequency input signal correction feedback signal.
3, a kind of auto frequency control apparatus as claimed in claim 1, it is characterized in that, described single subdistrict frequency correction information output module merges module, low pass filter, frequency offset calculation module and digitally controlled crystal oscillator by single subdistrict multipath frequency discrimination information and forms, be used to merge the frequency discrimination result of this sub-district receiving multipath signals, by filtering, ask frequency deviation, export the multipath signal frequency deviation correction feed-forward signal of this sub-district.
4, a kind of frequency correction equipment, radiofrequency signal processing module, multipath signal demodulation module and multipath signal merge module in comprising, it is characterized in that, also comprise multipath signal correction module, and as each described auto frequency control apparatus of claim 1 to 3;
Described auto frequency control apparatus receives the channel fading information that described multipath signal demodulation module sends, and according to channel fading information output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal;
Radiofrequency signal processing module in described according to the frequency input signal correction feedback signal of described auto frequency control apparatus output, is adjusted the frequency of input signal;
Described multipath signal correction module according to the multipath signal frequency deviation correction feed-forward signal of described auto frequency control apparatus output, is adjusted the fixedly frequency deviation of multipath signal;
Described multipath signal merges module, will carry out RAKE through each sub-district multipath signal of overcorrect and merge.
5, a kind of frequency correction equipment as claimed in claim 4 is characterized in that,
The radiofrequency signal processing module comprises radiofrequency signal receiver module, radio-frequency (RF) local oscillator output module and intermediate-freuqncy signal output module in described;
The radio-frequency (RF) local oscillator output module carries out demodulation to the radiofrequency signal that the radio frequency signal receiving module receives, and by intermediate-freuqncy signal output module output baseband signal.
6, a kind of frequency correction equipment as claimed in claim 5 is characterized in that, middle radiofrequency signal processing module is proofreaied and correct the radio frequency local oscillation signal according to the frequency input signal correction feedback signal that receives; Or, baseband signal is proofreaied and correct.
7, a kind of frequency correction equipment as claimed in claim 4 is characterized in that, further increases each district pilots channel measurement module, and the pilot signal after frequency correction and the decline correction is measured.
8, a kind of subscriber terminal equipment, at least comprise signal transmitting and receiving module and signal processing module, it is characterized in that, also comprise frequency correction equipment, described frequency correction equipment comprises: middle radiofrequency signal processing module, multipath signal demodulation module, multipath signal merge module, multipath signal correction module, and as each described auto frequency control apparatus of claim 1 to 3;
The received signal that described frequency correction equipment received signal transceiver module sends, demodulated received signal, obtain channel fading information, according to channel fading information input signal and multipath signal are carried out frequency correction, and the multipath signal after the frequency correction merged, signal after merging is sent to signal processing module, and the signal of signal processing module after to the merging that receives handled;
Described auto frequency control apparatus receives the channel fading information that described multipath signal demodulation module sends, and according to channel fading information output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal;
Radiofrequency signal processing module in described according to the frequency input signal correction feedback signal of described auto frequency control apparatus output, is adjusted the frequency of input signal;
Described multipath signal correction module according to the multipath signal frequency deviation correction feed-forward signal of described auto frequency control apparatus output, is adjusted the fixedly frequency deviation of multipath signal;
Described multipath signal merges module, will carry out RAKE through each sub-district multipath signal of overcorrect and merge.
9, a kind of subscriber terminal equipment as claimed in claim 8, it is characterized in that, in frequency correction equipment, further increase each district pilots channel measurement module, the pilot signal of frequency correction equipment output is measured, and measurement data is sent to the signal transmitting and receiving module.
10, a kind of method of frequency correction is characterized in that, in subscriber terminal equipment, may further comprise the steps:
The channel fading information of a, the output of auto frequency control apparatus receiving multipath signals demodulation module, according to channel fading information, output frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal; Described auto frequency control apparatus is each described auto frequency control apparatus of claim 1 to 3;
The frequency input signal correction feedback signal that b, middle radiofrequency signal processing module are exported according to described auto frequency control apparatus, the frequency of adjustment input signal; Multipath signal correction module is according to the multipath signal frequency deviation correction feed-forward signal of described auto frequency control apparatus output, the frequency deviation of proofreading and correct the multipath signal of multipath signal demodulation module output.
11, the method for a kind of frequency correction as claimed in claim 10 is characterized in that, before the described step a, the multipath signal demodulation module obtains the multipath information of each cell signal at first by Multipath searching, determines the demodulation sub-district;
Described Multipath searching mates relevant by the mode that reduces the coupling coherence length, select the demodulation sub-district fast.
12, the method for a kind of frequency correction as claimed in claim 10 is characterized in that, described step b further comprises:
Middle radiofrequency signal processing module is demodulated to baseband signal by the radio-frequency (RF) local oscillator signal with the radiofrequency signal that receives;
Middle radiofrequency signal processing module is proofreaied and correct the radio frequency local oscillation signal according to the frequency input signal correction feedback signal that receives; Or, baseband signal is proofreaied and correct.
13, the method for a kind of frequency correction as claimed in claim 10, it is characterized in that, comprise further among the step a that described auto frequency control apparatus selects the multipath signal of the highest sub-district of signal to noise ratio to produce frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal; Or the multipath signal of selecting signal to noise ratio to surpass the sub-district of predetermined value produces frequency input signal correction feedback signal and multipath signal frequency deviation correction feed-forward signal.
14, the method for a kind of frequency correction as claimed in claim 10 is characterized in that, after the step b, also comprises step b1:
Will be through the multipath signal of frequency correction, carry out each cell channel and estimate, to the multipath signal correction that declines.
15, the method for a kind of frequency correction as claimed in claim 14 is characterized in that, after the step b1, also comprises step b2:
The pilot channel of the multipath signal that decline is proofreaied and correct to process is measured, and metrical information is reported network side.
16, the method for a kind of frequency correction as claimed in claim 15 is characterized in that, the measurement of the pilot channel of the described multipath signal that decline is proofreaied and correct to process increases the coupling coherence length and mates relevant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100326302A CN100493224C (en) | 2006-01-04 | 2006-01-04 | Frequency correcting method and device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2006100326302A CN100493224C (en) | 2006-01-04 | 2006-01-04 | Frequency correcting method and device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1859675A CN1859675A (en) | 2006-11-08 |
| CN100493224C true CN100493224C (en) | 2009-05-27 |
Family
ID=37298526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2006100326302A Active CN100493224C (en) | 2006-01-04 | 2006-01-04 | Frequency correcting method and device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN100493224C (en) |
Families Citing this family (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101267230B (en) * | 2007-03-16 | 2011-08-10 | 德信无线通讯科技（北京）有限公司 | Testing method for Bluetooth RF correction |
| CN101499807B (en) * | 2008-02-01 | 2013-08-07 | 深圳富泰宏精密工业有限公司 | Self-calibration system and method for mobile phone power |
| CN101521528B (en) * | 2008-02-29 | 2012-12-05 | 中兴通讯股份有限公司 | Method and device for automatically adjusting the frequency deviation of crystal oscillator in GSM base station |
| GB0812089D0 (en) | 2008-07-02 | 2008-08-06 | Nec Corp | Mobile road communication device and related method of operation |
| CN101867386B (en) * | 2009-04-20 | 2013-10-02 | 电信科学技术研究院 | Method, system and device for pre-calibrating frequency deviation |
| CN101888647B (en) * | 2009-05-12 | 2013-04-24 | 普天信息技术研究院有限公司 | System and method for calibrating null interfaces among cells |
| CN101895323A (en) * | 2009-05-21 | 2010-11-24 | 大唐移动通信设备有限公司 | Method and device for sending signal |
| CN101932060A (en) * | 2009-06-19 | 2010-12-29 | 大唐移动通信设备有限公司 | Method, system and apparatus for frequency offset transmission and frequency offset precalibration |
| CN102369763B (en) * | 2011-08-30 | 2013-12-04 | 华为技术有限公司 | Frequency discrimination acquiring method, apparatus and device controlled by automatic frequency |
| CN104079510B (en) * | 2013-03-29 | 2017-05-24 | 上海贝尔股份有限公司 | Method and device for frequency offset estimation when user device switches cells |
| CN104639485B (en) * | 2013-11-12 | 2019-01-04 | 联咏科技股份有限公司 | Offset correction of carrier frequency method and offset correction of carrier frequency system |
| CN104579512B (en) * | 2015-01-23 | 2017-09-19 | 深圳市冠旭电子股份有限公司 | A kind of bluetooth frequency deviation adjusting method and device |
| CN106656361B (en) * | 2016-10-12 | 2020-09-15 | Oppo广东移动通信有限公司 | Frequency synchronization method and device |
| CN108123763A (en) * | 2017-12-26 | 2018-06-05 | 中国铁路信息技术中心 | Frequency difference compensation method and device |
| CN108600132A (en) * | 2018-04-08 | 2018-09-28 | 深圳市盛路物联通讯技术有限公司 | A kind of transmitting frequency calibration method, system, equipment and computer readable storage medium |
| CN113225274B (en) * | 2021-04-14 | 2023-11-03 | 西安宇飞电子技术有限公司 | Fast-moving multipath channel model measurement method |
-
2006
- 2006-01-04 CN CNB2006100326302A patent/CN100493224C/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN1859675A (en) | 2006-11-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100493224C (en) | Frequency correcting method and device | |
| JP3214466B2 (en) | Mobile communication system, communication control method therefor, base station and mobile station used for the same | |
| EP1750472B1 (en) | Apparatus and method for performing handoff in a communication system | |
| US5483668A (en) | Method and apparatus providing handoff of a mobile station between base stations using parallel communication links established with different time slots | |
| US6856611B2 (en) | Radio interface synchronization | |
| US20110269449A1 (en) | Subcell Measurement Procedures in a Distributed Antenna System | |
| US7164889B2 (en) | Mobile communication system | |
| KR100953583B1 (en) | Mobile communication terminal and transmission power control method | |
| CN102299730B (en) | A kind of antenna correcting method based on TDD coordinated multipoint transmission and system | |
| US6907014B1 (en) | Apparatus and method for TDMA-TDD based transmission/reception | |
| US20090290557A1 (en) | Calculation of a destination time alignment value to be used by a user equipment in a destination cell after a handover | |
| US20220231883A1 (en) | Methods and Apparatus for Measurement and UE Antenna Selection | |
| KR100402565B1 (en) | Base station device and transmission power control method | |
| KR20040060274A (en) | method for controlling a power of the radio links | |
| CN116015411B (en) | High dynamic terminal and switching method for satellite mobile communication system | |
| CN102264113B (en) | Virtual soft switching method in time division-synchronous code division multiple access (TD-SCDMA) system | |
| US6999765B2 (en) | CDMA type mobile station having first and second receiving portions for rounding off a chip offset temporally early and late | |
| WO2006064391A1 (en) | Method and apparatus for use in handover measurement process | |
| US7269421B2 (en) | Control of frame timing on handover | |
| US8442444B2 (en) | Method of transmit power control and device thereof | |
| CN101932060A (en) | Method, system and apparatus for frequency offset transmission and frequency offset precalibration | |
| CN101771434A (en) | Method for adjusting frequency deviation of mobile terminal and device thereof | |
| CN101801048B (en) | Method for setting transmission time sequence and initial transmission advance time sequence of uplink | |
| Kurniawan | Effect of feedback delay on fixed step and variable step power control algorithms in CDMA systems | |
| EP1351535B1 (en) | Control of frame timing on handover |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20211222 Address after: 450046 Floor 9, building 1, Zhengshang Boya Plaza, Longzihu wisdom Island, Zhengdong New Area, Zhengzhou City, Henan Province Patentee after: xFusion Digital Technologies Co., Ltd. Address before: 518129 intellectual property department, Bantian HUAWEI headquarters, Longgang District, Shenzhen, Guangdong Patentee before: HUAWEI TECHNOLOGIES Co.,Ltd. |
|
| TR01 | Transfer of patent right |