CN101917364B - Equalizer based on training sequences and realization method thereof - Google Patents
Equalizer based on training sequences and realization method thereof Download PDFInfo
- Publication number
- CN101917364B CN101917364B CN 201010255505 CN201010255505A CN101917364B CN 101917364 B CN101917364 B CN 101917364B CN 201010255505 CN201010255505 CN 201010255505 CN 201010255505 A CN201010255505 A CN 201010255505A CN 101917364 B CN101917364 B CN 101917364B
- Authority
- CN
- China
- Prior art keywords
- data
- training sequence
- feedforward filter
- equalizer
- buffer
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)
Abstract
The embodiment of the invention provides an equalizer based on training sequences and a realization method thereof. The method comprises the following steps: buffering the receiving data by a buffer with the depth shown in the specification, wherein Lpayload is the length of payload symbols between the training sequences, Ltrain is the number of the training sequence data and Lfilter is the orderof a feed forward filter; writing the training sequences and adjacent data of the training sequences in the buffer in each tap of the feed forward filter according to the time sequence after the training sequences reach the buffer and ensuring the training sequences in the middle positions of the taps of the feed forward filter; carrying out feed forward filtering, carrier synchronizing and errorextracting on the data in the feed forward filter to obtain the equalizer parameters corresponding to the training sequences; and restoring the data to be restored by utilizing the equalizer parameters. The equalizer and the realization method thereof of the embodiment of the invention can be applicable to wider training sequence gaps under the condition of obtaining the same receiver performanceand improve the utilization factor of the frequency spectrum.
Description
Technical field
The present invention relates to microwave communication, relate in particular to a kind of equalizer based on training sequence and its implementation.
Background technology
In the wireless digital microwave communication, for improving receiver performance, reduce the data transmission error rate, receiving terminal need recover channel with equalizer.Be the blindness of avoiding channel to recover, the transmitting terminal cycle sends training sequence, and receiving terminal carries out parametric equalizer according to training sequence and extracts.The training sequence here can be pilot tone or lead code.
Because there is dynamic characteristic in the microwave transmission channel, on the one hand, transfer of data is subject to atmospheric effect, reflects, reflection and scattering, declines thereby produce dynamic multi-path, and namely the multipath recess is in continuous movement; On the other hand, the microwave communication audio range frequency is higher, and the local oscillator of radio-frequency module is subject to temperature, the pressure iso-stress changes shake and the drift that produces frequency, influences carrier synchronization.Therefore, to the Quick-Change channel of the shake of dynamic multi-path and carrier frequency point, drift, training sequence needs enough weak points at interval, parametric equalizer can be accessed upgrade in time, in time reflects channel variation, could guarantee the data recovery correctly.But, please refer to data frame format shown in Figure 1, it is wide that training sequence takies data carousel, and training sequence is short at interval, means that the availability of frequency spectrum is low.
Fig. 2 is the structural representation of existing equalizer, please refer to Fig. 2, the symbol sebolic addressing of r (n) for receiving, and S (n) is r (n) is feedovered filtering and the postrotational symbol sebolic addressing of phase place,
Be known training sequence,
And the difference of S (n) is e (n).Frame synchronization module is to utilize known training sequence and receive signal to do relevantly, finds the training sequence position according to relevant peaks; Feedforward filter FFF (Feed Forward Filter) structure is a FIR (Finite Impulse Response, the response of limit for length's unit impulse is arranged) filter, major function is ISI (the Inter-Symbol Interference that the erasure signal distortion is introduced, intersymbol interference), coefficient update is according to LMS (Least mean square, least mean square algorithm) principle, formula are w (n+1)=w (n)-μ e (n) x
*(n).Please continue with reference to Fig. 2, the carrier synchronization function is mainly finished in the rotation of phase demodulation, phase place and three unit of phase place derotation: the phase demodulation unit obtain S (n) and
Between phase difference, and carry out loop filtering, obtain characterizing the phase deviation of phase place and Frequency Synchronization
Will
Give the phase place rotary unit after the negate, the signal of feedforward filter being sent here at the phase place rotary unit carries out the phase place selection, finishes phase place and the Frequency Synchronization of carrier wave.Phase place derotation module is that e (n) phase place is rotated
Purpose is for the error before the use carrier synchronization when upgrading feed-forward filter coefficients.
In existing scheme, please refer to Fig. 3, employing be that N section training sequence obtains parametric equalizer w (n), recover to the data of payload between the N+1 section training sequence in order to finish N section training sequence.Waiting to recover the ultimate range that data time of reception and respective equalizers parameter obtain the time is L
Paylaod* T, wherein, L
PaylaodBe the length of payload symbols between the training sequence, T is a data symbol duration.Because waiting to recover the ultimate range of data time of reception and respective equalizers parameter acquisition time is L
Paylaod* T in order to follow the tracks of Quick-Change channel, needs L
PaylaodEnough little, lowered the availability of frequency spectrum.
Summary of the invention
The embodiment of the invention provides a kind of equalizer based on training sequence and its implementation, channel information with the acquisition of better utilization training sequence, payload data is recovered, obtaining to be suitable for bigger training sequence under the same receiver performance at interval, to improve the availability of frequency spectrum.
The above-mentioned purpose of the embodiment of the invention is achieved by the following technical solution:
A kind of implementation method of the equalizer based on training sequence, described method comprises:
With the degree of depth be
The buffer buffer memory receive data, wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number;
After training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position;
Feedover filtering, carrier synchronization and error of data in the described feedforward filter extracted, obtained the parametric equalizer of described training sequence correspondence;
Utilize described parametric equalizer to treat the recovery data and carry out the data recovery.
A kind of equalizer based on training sequence, described equalizer comprise feedforward filter, coefficient update unit, phase place rotary unit, phase place derotation unit, phase demodulation unit, training sequence generator and frame synchronization unit, and described equalizer also comprises:
Buffer is used for buffer memory and receives data, and the degree of depth of described buffer is
Wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number;
Controller, be used for after training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of described feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position, the filtering so that described feedforward filter feedovers, and described coefficient update unit, the phase place rotary unit, phase place derotation unit, the phase demodulation unit, training sequence generator and frame synchronization unit carry out carrier synchronization and error is extracted, obtain the parametric equalizer of described training sequence correspondence, and utilize described parametric equalizer to treat the recovery data and carry out the data recovery.
The equalizer of the embodiment of the invention and its implementation are recovered payload data for the channel information that the better utilization training sequence obtains, and obtaining can be suitable for bigger training sequence under the same receiver performance at interval, improve the availability of frequency spectrum.
Description of drawings
Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, does not constitute limitation of the invention.In the accompanying drawings:
Fig. 1 is the data frame format schematic diagram;
Fig. 2 is the structural representation of existing equalizer;
Fig. 3 utilizes existing equalizer to carry out the parametric equalizer schematic diagram that data are recovered;
Fig. 4 is the flow chart of implementation method of the equalizer of the embodiment of the invention;
Fig. 5 is the structural representation of the equalizer of the embodiment of the invention.
Embodiment
For the purpose, technical scheme and the advantage that make the embodiment of the invention is clearer, below in conjunction with embodiment and accompanying drawing, the embodiment of the invention is described in further details.At this, illustrative examples of the present invention and explanation thereof are used for explanation the present invention, but not as a limitation of the invention.
The flow chart of the implementation method of a kind of equalizer based on training sequence that Fig. 4 provides for the embodiment of the invention please refer to Fig. 4, and this method comprises:
Step 401: be with the degree of depth
The buffer buffer memory receive data, wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number;
Step 402: after training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position;
Wherein, feedforward filter is the FIR filter, and for feedforward filter, each grade all preserved an input sample through time-delay, and input at different levels connects with exporting to be connected and is called as tap.For example, the feedforward filter on M rank will have M+1 tap.Optionally, adjacent data length in front and back can be less than or equal to
Step 403: feedover filtering, carrier synchronization and error of the data in the described feedforward filter extracted, obtained the parametric equalizer of described training sequence correspondence;
Step 404: utilize described parametric equalizer to treat the recovery data and carry out the data recovery.
Wherein, because data to be recovered are arranged in buffer, therefore, behind the parametric equalizer that has obtained the training sequence correspondence, can utilize this parametric equalizer that the data to be recovered in the buffer are carried out data and recover.In one embodiment, this can be waited to recover data and front and back adjacent data thereof write feedforward filter according to time sequencing each tap, guarantee that this waits to recover data in this feedforward filter taps centre position, so can utilize this parametric equalizer that these data to be recovered are carried out data recovers, specifically can realize by existing technological means, not repeat them here.
Wherein, wait to recover data and be the adjacent data before and after this training sequence, comprise the of payload before this training sequence
To L
PayloadIndividual data, and the 1st data to the of payload behind this training sequence
Individual data.Please refer to Fig. 3, suppose that this training sequence is the corresponding training sequence of W (N+1) shown in the figure, then before this training sequence the of payload
Individual data are to L
PayloadIndividual data are the latter half in the N segment data shown in the figure (the oblique line part in the N segment data), and the 1st of payload the data to the behind this training sequence
Individual data are the first half in the N+1 segment data shown in the figure (the oblique line part in the N+1 segment data).
The implementation method of the equalizer of present embodiment is considered the second half section of N segment data symbol (also being payload), more close N+1 section training sequence on time, the characteristic of channel more conforms to the parametric equalizer that N+1 section training sequence recovers, adopt as above method, the parametric equalizer W (N+1) that utilizes N+1 section training sequence to recover realizes the data recovery of the second half section of N segment data symbol.
The implementation method of the equalizer that provides by the embodiment of the invention adapts to Quick-Change channel, identical training sequence at interval down, the balanced data recovered error rate reduces, and improves system's anti-phase jump ability and anti-dynamic multi-path interference performance.Compare with prior art, obtain same the reception under the error rates of data condition at same channel condition, training sequence can enlarge twice at interval, has effectively improved the availability of frequency spectrum.
The structural representation of the equalizer that Fig. 5 provides for the embodiment of the invention, please refer to Fig. 5, this equalizer is except comprising existing feedforward filter, phase place rotary unit, training sequence generator, phase demodulation unit, phase place derotation unit, coefficient update unit and frame synchronization unit, also comprise buffer 51 and controller (not shown), wherein:
Wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number.
Controller is used for after training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of described feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position, the filtering so that described feedforward filter feedovers, and described phase place rotary unit, the training sequence generator, the phase demodulation unit, phase place derotation unit, coefficient update unit and frame synchronization unit carry out carrier synchronization and error is extracted, obtain the parametric equalizer of described training sequence correspondence, and utilize described parametric equalizer to treat the recovery data and carry out the data recovery.
When carrying out the data recovery, this controller also is used for describedly waiting recovering data and front and back adjacent data thereof write described feedforward filter according to the reception sequencing each tap, guarantee describedly to wait to recover data in described feedforward filter taps centre position, recover so that described feedforward filter, phase place rotary unit, training sequence generator, phase demodulation unit, phase place derotation unit, coefficient update unit and the described parametric equalizer of frame synchronization unit by using carry out data to data described to be recovered.
Same, this is waited to recover data and is the of payload before this training sequence
Individual data are to L
PayloadIndividual data, and the 1st data to the of payload behind this training sequence
Individual data.
The embodiment of the invention is by increasing a buffer (buffer) and control circuit in equalizer.In N section payload, the
To L
PaylaodThe recovery of individual data needs N+1 section training sequence to obtain, and therefore, receives data by this buffer buffer memory, and the buffer degree of depth is
L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number.After treating that N+1 section training sequence arrives buffer, training sequence and front and back adjacent data thereof are write each tap of feedforward filter in chronological order, guarantee that the data of training sequence are in this feedforward filter taps centre position, filtering, carrier synchronization and the error of feedovering then extracted, and obtains the parametric equalizer of N+1 section training sequence correspondence.After getting parms, from N segment data
Individual data begin, and its adjacent data is write each tap of feedforward filter by receiving sequencing, guarantee to wait to recover data in this feedforward filter taps centre position, adopt the conventional means of prior art to carry out the data recovery then.
Each part of the equalizer of present embodiment and function thereof are identical with each step of the method for previous embodiment, owing in method embodiment, each step is had been described in detail, do not repeat them here.
The equalizer that the embodiment of the invention provides can adapt to Quick-Change channel, and under identical training sequence interval, the balanced data recovered error rate reduces, and improves system's anti-phase jump ability and anti-dynamic multi-path interference performance.Compare with prior art, obtain same the reception under the error rates of data condition at same channel condition, training sequence can enlarge twice at interval, has effectively improved the availability of frequency spectrum.
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; and be not intended to limit the scope of the invention; within the spirit and principles in the present invention all, any modification of making, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (2)
1. the implementation method based on the equalizer of training sequence is characterized in that, described method comprises:
With the degree of depth be
The buffer buffer memory receive data, wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number;
After training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position;
Feedover filtering, carrier synchronization and error of data in the described feedforward filter extracted, obtained the parametric equalizer of described training sequence correspondence; And
Utilize described parametric equalizer to treat the recovery data and carry out the data recovery;
Wherein, the step of utilizing described parametric equalizer that data described to be recovered are carried out the data recovery comprises:
Wait to recover data and front and back adjacent data thereof and write each tap of described feedforward filter according to time sequencing described, guarantee describedly to wait to recover data in described feedforward filter taps centre position; And
Utilizing described parametric equalizer to carry out data recovers;
Wherein, data described to be recovered be before the described training sequence payload the
Individual data are to L
PayloadIndividual data, and the 1st data to the of payload behind the described training sequence
Individual data.
2. equalizer based on training sequence, described equalizer comprises feedforward filter, coefficient update unit, phase place rotary unit, phase place derotation unit, phase demodulation unit, training sequence generator and frame synchronization unit, it is characterized in that described equalizer also comprises:
Buffer is used for buffer memory and receives data, and the degree of depth of described buffer is
Wherein, L
PayloadBe the length of the payload symbols between the training sequence, L
TrainBe training sequence data number, L
FilterBe the feedforward filter exponent number;
Controller, be used for after training sequence arrives described buffer, training sequence described in the described buffer and front and back adjacent data thereof are write each tap of described feedforward filter according to time sequencing, guarantee that described training sequence is in described feedforward filter taps centre position, the filtering so that described feedforward filter feedovers, and described coefficient update unit, the phase place rotary unit, phase place derotation unit, the phase demodulation unit, training sequence generator and frame synchronization unit carry out carrier synchronization and error is extracted, obtain the parametric equalizer of described training sequence correspondence, and utilize described parametric equalizer to treat the recovery data and carry out the data recovery;
Wherein, described controller also is used for waiting to recover data and front and back adjacent data thereof write described feedforward filter according to time sequencing each tap with described, guarantee describedly to wait to recover data in described feedforward filter taps centre position, recover so that described feedforward filter, coefficient update unit, phase place rotary unit, phase place derotation unit, phase demodulation unit, training sequence generator and the described parametric equalizer of frame synchronization unit by using carry out data to data described to be recovered;
Wherein, data described to be recovered be before the described training sequence payload the
Individual data are to L
PayloadIndividual data, and the 1st data to the of payload behind the described training sequence
Individual data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010255505 CN101917364B (en) | 2010-08-13 | 2010-08-13 | Equalizer based on training sequences and realization method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010255505 CN101917364B (en) | 2010-08-13 | 2010-08-13 | Equalizer based on training sequences and realization method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101917364A CN101917364A (en) | 2010-12-15 |
| CN101917364B true CN101917364B (en) | 2013-10-09 |
Family
ID=43324755
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010255505 Expired - Fee Related CN101917364B (en) | 2010-08-13 | 2010-08-13 | Equalizer based on training sequences and realization method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101917364B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103684601B (en) * | 2012-09-14 | 2016-04-20 | 富士通株式会社 | Coefficient determining device, equalizer, Receiver And Transmitter |
| CN112714084B (en) * | 2019-10-24 | 2023-09-26 | 上海诺基亚贝尔股份有限公司 | Apparatus, method, and computer-readable storage medium for optical communication |
| CN113300703B (en) * | 2021-05-24 | 2023-03-14 | 成都振芯科技股份有限公司 | Self-adaptive equalization device and method based on phase detection |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1188578A (en) * | 1995-05-10 | 1998-07-22 | 艾奥尼卡国际有限公司 | Demodulator and method of demodulation in TDM receiver |
| CN100518153C (en) * | 2005-03-01 | 2009-07-22 | 美国博通公司 | Method and device for carrying out balanced treatment for RF pulse |
-
2010
- 2010-08-13 CN CN 201010255505 patent/CN101917364B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN101917364A (en) | 2010-12-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1998136B (en) | Advanced digital receiver | |
| US7889786B2 (en) | Operating frequency reduction for transversal FIR filter | |
| CN101567863B (en) | Indirect self-adaptive balancing method of shallow-sea underwater acoustic communication system | |
| WO2008115702A1 (en) | Adaptive equalizer for communication channels | |
| JP7140681B2 (en) | Method and system for communication using heterogeneous links | |
| US20180375693A1 (en) | Phase delay difference-based channel compensation | |
| WO2004010628A1 (en) | Training prefix modulation method and receiver | |
| CN105245478B (en) | A kind of adaptive equalization algorithm based on qam mode | |
| CN103401821A (en) | Adaptive equalizer of Bluetooth 4.0 low-power receiver and implementation method of adaptive equalizer | |
| US8681910B2 (en) | Hybrid equalization system | |
| CN102333063A (en) | Uplink channel estimation and carrier synchronization method and device applied to indoor frequency division duplex-long term evolution (FDD-LTE) scene | |
| CN101917364B (en) | Equalizer based on training sequences and realization method thereof | |
| CN103841064B (en) | SISO balancing method based on sampling rate data and balancer | |
| CN102437978A (en) | Method and device for balancing digital microwaves | |
| CN101997790B (en) | Channel estimation device and method based on time domain pilot frequency sequence | |
| Sifferlen et al. | An iterative equalization and decoding approach for underwater acoustic communication | |
| JP2002510167A (en) | Channel characteristic tracking method and apparatus | |
| CN106534011B (en) | receiver and related control method | |
| US7933323B2 (en) | Method and system for performing timing recovery in a digital communication system | |
| CN107948111B (en) | Sampling frequency offset correction method of OFDM system | |
| CN104683284B (en) | The OFDM/OFDMA symbol cyclic shift equalization methods of cyclic prefix are not needed | |
| CN107078981A (en) | Frequency estimation | |
| CN103685102B (en) | A kind of time domain equalization implementation method of broadband signal | |
| CN100393115C (en) | Channel self-adapting equilibrium method for digital television | |
| CN106533646B (en) | Clock Data Recovery System in Sequencer/Deserializer |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20131009 Termination date: 20200813 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |