CN1492610A - Multipath searching method and device in CDMA system - Google Patents
Multipath searching method and device in CDMA system Download PDFInfo
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Abstract
This invention discloses a multipath searching method in CDMA system adding a signal jump detection step based on the present multipat searching method. After getting a result of energy accumulation for each sample phase signal the existence of signal jump is judged in terms of the said result, if so, smaller filter coefficient is set or larger one is set, enabling to get quick multipath search to the exist and vanish after searching out the multipath in the same strength to traditional way channels after searching out the multipath in the same strength to traditional way so as to select filter coefficient effectively to unify the quickness and stability of multipath search.
Description
Technical field
The present invention relates to synchronization acquiring method and device that the base band of receiving synchronous method and device, especially code division multiple access (CDMA) system of wireless telecommunication system receives.
Background technology
The phenomenon of ubiquity multipath transmission in the mobile communication, promptly signal arrives receiver from the transmitter emission through too much transmission paths.Every there is different transmission delays in the footpath, different declines and different phase places, and its multipath reception signal mixes when arriving receiver can cause the multipath fading phenomenon.
In cdma system, because the combined influence of the factors such as non-synchronous fully and noise of the imperfection of the length of sign indicating number, sign indicating number, system, actual multipath situation as shown in Figure 1.Each the desirable peak value 101-106 that there is shown signal represents time and the intensity that multipath occurs.And the energy that obtains in the reality in time situation of change be shown in the pattern 20.Situation for 20, multipath peak then are difficult to differentiate.Particularly, for 104,106 two less peak values of energy, then can distinguish hardly.And, then rule out to possible errors and have multipath for the higher position of some noise energies.
Because cdma system belongs to the exigent system of signal correlation, so it requires very high to the synchronism between base station and the subscriber equipment (UE).When the frame head position of base station transmit signals frame head position and subscriber equipment (UE) received signal differs 1 chip when above, the just noise signal that subscriber equipment then can obtain, but not expectation information.The general RAKE receiver technology that adopts is carried out time diversity and merging to the multipath interval greater than a chip in present cdma system, obtains better receptivity.
Present cdma system RAKE receiver structure is with reference to figure 2.Wireless signal obtains baseband signal through the processing of antenna 31, radio-frequency channel 32, shaping filter unit 33 and down-converter unit 34, this signal input RAKE receiver 35, is the symbol level signal by RAKE receiver 35 with base band signal process, exports to decoding unit 36; And decoding unit 36 the most at last the symbol level signal processing be Bit data with actual physics meaning, export to later cell processing.
RAKE receiver 35 is the distinctive signal handling equipments of cdma system, and its structure chart is with reference to figure 3, and it can utilize the bigger processing gain of multipath information acquisition.In RAKE receiver 35, definite function of each multipath relative time position in the baseband signal is finished in Multipath searching unit 350, and multipath peak (phase place) information of its acquisition outputs to multipath allocation units 351.The multipath allocation units are finished the initial solution adjusted position distribution function to each despreading descrambling unit 3521-352N, are output as the multipath assignment commands of each despreading descrambling unit.Each despreading descrambling unit 3521-352N finishes the function of baseband signal being carried out demodulation (despreading descrambling) in definite zero-time position, and its output symbol level signal is to its corresponding multipath tracking unit 3531-353N and automatic frequency control unit 3541-354N.Multipath tracking unit 3531-353N finishes the meticulous regulatory function to corresponding despreading descrambling position, and the Output Tracking Control order is to corresponding despreading descrambling unit.Automatic frequency control unit 3541-354N, channel estimating unit 3551-355N and channel compensate bank 3561-356N connect successively, finish compensation and correction to signal jointly, and its last output symbol level signal is to multipath merge cells 357.Multipath merge cells 357 is finished the pooling function of each multipath through compensating signal, and its output is handled as the level unit, back that outputs to of RAKE receiver.
The general synchronously synchronous mode of two-stage that adopts of cdma system: Multipath searching and multipath tracking.The scope that Multipath searching can obtain multipath is big, but capture time is long and time precision is relatively poor relatively; Multipath tracking handle rapidly and also time precision high, but its, scope was little action time.Usually system utilizes Multipath searching to obtain the rough position of multipath peak value, utilizes the precision of multipath tracking adjusting multipath phase place and overcomes possible the moving of multipath peak value in the Multipath searching cycle.
The general structure of Multipath searching unit as shown in Figure 4.Baseband signal is after despreading descrambling unit/unit group 41 is handled, and the power spectrum (the despreading descrambling output energy of corresponding different time position) that obtains delaying time outputs to each phase place smooth unit 42.Each phase place smooth unit 42 is finished the smoothing function of each corresponding phase, reaches the effect that suppresses noise, and it exports peak filter 43 to.Peak filter 43 detects the position and the corresponding energy of the peak value of input time delay power spectrum, exports threshold judgement unit/unit group 44 to.Threshold judgement unit/unit group 44, whether adjudicate corresponding peak value is the multi-path location of signal, if be multi-path location then export its phase information, possible threshold judgement unit/unit group also needs despreading descrambling unit/unit group 41 to transmit control signal.
In Multipath searching unit shown in Figure 4, the processing speed is-symbol level (perhaps slower speed step) of each phase place smooth unit 42, peak filter 43 and threshold judgement unit/unit group 44, the back-end processing part be called; Corresponding despreading descrambling unit/group 41 processing speeds in unit are very fast, are called the front-end processing part.Wherein, each phase place smooth unit 42 main effect is: suppress the influence of ubiquitous noise to multi-path judging, and the big noise of burst is limited.At present, each phase place smooth unit 42 adopts linear filter (FIR: finite impulse response filter or IIR: IIR filter).The most frequently used is the first order IIR filtering device, and its structure as shown in Figure 5.The output of this part by input and the product (finishing) of filter coefficient 1-α and output with multiplier 71 through the product of time-delay (finishing) and factor alpha (finishing) with multiplier 72 by delay register 73 with (carrying out computing) by adder 74.The parameter of this part is filter coefficient α, and factor alpha is bigger, system stability then, and false alarm probability is lower, but corresponding capture time for the multipath that occurs is also long; Factor alpha is less, system's sensitivity then, and corresponding capture time for the multipath that occurs is also short, but false alarm probability is also corresponding higher, false-alarm is merged for the multipath of RAKE receiver and be brought unnecessary noise, occurs erroneous judgement easily, and the resource of waste despreading descrambling unit.
In the actual environment, the appearance of multipath and the multiple situation of possibility that disappears.A kind of situation is so-called static channel, and promptly fixedly there is multipath in this phase place, just owing to fade-out, and the appearance of the multipath that causes and disappearance.For this situation, adopt factor alpha more suitable.Also having a kind of typical case is the so-called life channel that goes out, and does not promptly originally exist or exist the phase place of multipath to occur stronger multipath suddenly or multipath disappears.This phenomenon generally because the user moves away or enters the shadow region and causes, adopts less being beneficial to of factor alpha to catch.Occur or nonvolatile mode owing to can't determine the multipath on each phase place in the General System, so adopt a kind of side reaction coefficient of compromise usually.All can't reach best search effect for different multipath appearance or nonvolatile mode like this.
Summary of the invention
The objective of the invention is to, a kind of Multipath searching effect multipath searching method and device in the code division multiple access system preferably is provided, use this method or device can determine effectively that the multipath of each phase place occurs or nonvolatile mode, the selective filter coefficient makes Multipath searching reach rapidity and stable unification effectively.
For achieving the above object, the multipath searching method in the code division multiple access system provided by the invention comprises:
Step 1: baseband signal is carried out front-end processing, the I of each sampling phase correspondence of picked up signal, Q two paths of data;
Step 2: I, the Q two paths of data of each sampling phase correspondence that step 1 is obtained are handled respectively, obtain the energy of each sampling phase signal;
Step 3: the energy of each sampling phase signal that step 2 is obtained carries out the irrelevant of rear end and adds up, and obtains each sampling phase signal energy accumulation result;
Step 4: judge whether to exist sign mutation,, filter coefficient α=α 1 is set, otherwise filter coefficient α=α 2 is set if exist;
Wherein: α 1 is the less filter coefficient of predetermined numerical value; α 2 is the bigger filter coefficients of predetermined numerical value;
Step 5: to each sampling phase signal energy accumulation result that obtains in the step 3, the filter coefficient that adopts step 4 to determine according to the corresponding criterion of sampled point carries out filtering respectively, obtains the filtered signal energy of each sampling phase correspondence;
Step 6: the filtered signal energy of each sampling phase correspondence that obtains for step 5, carry out the multi-path location judgement, obtain and export the phase information of each multipath.
Described step step 4 further comprises:
Step 41: for each sampling phase signal energy accumulation result that step 3 obtains, corresponding each phase place is carried out calculus of differences, output energy difference score value;
Step 42: the absolute value of the energy difference that obtains for step 41 carries out the threshold value judgement, if the absolute value absolute value of energy difference greater than threshold value then α=α 1, otherwise α=α 2;
Multipath searching method in the another kind of code division multiple access system provided by the invention comprises:
Steps A 1: baseband signal is carried out front-end processing, the I of each sampling phase correspondence of picked up signal, Q two paths of data;
Steps A 2: each sampling phase correspondence that steps A 1 is obtained I, Q two paths of data handle respectively, obtain the energy of each sampling phase signal;
Steps A 3: the energy of each sampling phase that steps A 2 is obtained carries out the irrelevant of rear end and adds up, and obtains each sampling phase signal energy accumulation result;
Steps A 4: judge whether to exist sign mutation,, select fast but the low filter of stability, otherwise select stable but the relatively poor filter of rapidity if exist;
Steps A 5: to each sampling phase signal energy accumulation result that obtains in the steps A 3, the filter that adopts steps A 4 to determine according to the corresponding criterion of sampled point carries out filtering respectively, obtains the filtered signal energy of each sampling phase correspondence;
Steps A 6: the filtered signal energy of each sampling phase correspondence that obtains for steps A 5, carry out the multi-path location judgement, obtain and export the phase information of each multipath.
Multipath searching device in the code division multiple access system provided by the invention, comprise despreading descrambling unit, peak filter, threshold judgement unit, it is characterized in that, also comprise energy calculation unit, the irrelevant unit that adds up, filter factor determining unit and each phase filtering unit, wherein:
Energy calculation unit is used to finish the energy calculating to each phase signal of despreading descrambling element output signal correspondence, and result of calculation inputs to the irrelevant unit that adds up;
The irrelevant unit that adds up is used to finish the irrelevant of each signal phase energy and adds up, and accumulation result exports each phase filtering unit and filter factor determining unit to;
The filter factor determining unit is used for determining the filter factor that each phase filtering unit uses in corresponding phase according to the irrelevant signal that adds up unit output;
Each phase filtering unit is used for carrying out the filtering of each phase signal according to the corresponding phase signal of the irrelevant unit output that adds up and the filter factor of each phase place that the filter factor determining unit is determined.
Described filter factor determining unit comprises Difference Calculation module, absolute calculation module and filter factor selection module, wherein:
The Difference Calculation module is used for choosing some time-delays power spectrum corresponding phase signal from the irrelevant signal that adds up unit output and carries out the signal energy calculus of differences, and operation result outputs to the absolute calculation module;
The absolute calculation module is used to finish the calculating of the absolute value of energy difference, and result of calculation outputs to filter factor and selects module;
Filter factor is selected module, is used for determining according to the threshold value of absolute calculation module and regulation the filter factor of the corresponding phase of each phase filtering unit needs.
Described Difference Calculation module comprises:
Subtracter is used to finish this input signal and the last time reducing mutually of energy signal;
Memory is used to store last time energy signal;
Controller is used for the last time signal data output of control storage.
Because the present invention judges whether to exist sign mutation according to each sampling phase signal energy accumulation result that obtains, and the filtering mode that selection is fit to according to judged result, this makes the present invention under the prerequisite that searches out with the multipath of the same intensity of conventional method, can obtain to make the Multipath searching cycle that is used for a user shorten to giving birth to the rapidity of the channel multi-path searching that goes out.For a user, this rapidity can reduce the cycle of Multipath searching, increases the adaptive capacity to emergent multipath.For a plurality of users, this rapidity makes a Multipath searching unit become possibility to a plurality of user's time division multiplexinges, can reduce the overall cost of receiver system.As seen, the present invention can determine effectively that the multipath of each phase signal occurs or nonvolatile mode owing to adopted sign mutation to detect link, therefore can select filter coefficient alpha effectively, makes Multipath searching reach the unification of rapidity and stability.
Description of drawings
Fig. 1 is the schematic diagram of multipath signal in the cdma system;
Fig. 2 is a signal receiver structure chart in the cdma system;
Fig. 3 is the structure chart of the RAKE receiver that adopts of signal receiver shown in Figure 2;
Fig. 4 is the Multipath searching cellular construction figure of RAKE receiver shown in Figure 3;
Fig. 5 is the first order IIR filtering device structure chart that Multipath searching unit shown in Figure 4 adopts;
Fig. 6 is the embodiment flow chart of the method for the invention;
Fig. 7 is the example structure figure of device of the present invention;
Fig. 8 is the filter factor determining unit structure chart that Fig. 7 adopts;
Fig. 9 is the Difference Calculation modular structure figure that Fig. 8 adopts;
Figure 10 is each phase filtering cellular construction figure that Fig. 7 adopts.
Embodiment
By to giving birth to the situation analysis of the channel multi-path that goes out, can think that the appearance of signal multipath or disappearance are a kind of unexpected saltus step of signal, can represent with step function.Sudden change for sort signal can utilize edge detection method to detect.Essence of the present invention is to have adopted sign mutation to detect link, detects link by this, determines that effectively the multipath of each phase place occurs or nonvolatile mode, and then selects filter coefficient alpha effectively, makes Multipath searching reach the unification of rapidity and stability.
The present invention is described in further detail below in conjunction with accompanying drawing.
Fig. 6 is the embodiment flow chart of the method for the invention.Implement the present invention according to Fig. 6, at first carry out the I that front-end processing obtains each sampling phase correspondence in 1 pair of baseband signal of steps A, the Q two paths of data, wherein each road comprises a plurality of data, the I of each sampling phase correspondence that obtains in 2 pairs of steps A of steps A 1, a plurality of data of Q two-way are carried out relevant the adding up (can select to add up or do not add up) of rear end respectively, obtain the I of each sampling phase signal, the accumulation result of Q two paths of data, the I of each sampling phase signal that obtains in 3 pairs of steps A of steps A 2 then, Q two-way accumulation result, carry out the square operation of I road and Q road signal respectively, again the summation of the result behind two square operations of corresponding each sampling phase signal is obtained the energy of corresponding each sampling phase signal; The energy of each sampling phase signal that obtains for steps A 3 in steps A 4 carries out irrelevant the adding up (can select to add up or do not add up) of rear end, obtains the energy accumulation result of each sampling phase signal; Then in steps A 5 for the result among the above-mentioned steps A4, corresponding each phase place is carried out calculus of differences, promptly deducts the energy value of last time with current energy value, obtains the energy difference score value; The absolute value of the energy difference result that obtains for steps A 6 in steps A 7 carries out the threshold value judgement, to judge whether to exist sign mutation, if absolute value is greater than threshold value, illustrate and have sign mutation, then select α 1 as filter factor in steps A 8, promptly α=α 1, otherwise there is not sign mutation in explanation, therefore select α 2 as filter factor in steps A 9, promptly α=α 2; After filter factor is determined, in the energy accumulation result of steps A 10 for each sampling phase signal of steps A 4 acquisitions, carry out first order IIR filtering according to the corresponding criterion of sampled point respectively, filter coefficient is the α that determines in steps A 8 or the steps A 9, obtains the filtered energy of each sampling phase signal correspondence; At the filtered energy of steps A 11 for each sampling phase correspondence of steps A 10 acquisitions, carry out the multi-path location judgement, obtain the phase information of each multipath signal, at last in the phase information output of steps A 12 with above-mentioned multipath signal.
Determine by system emulation in this example of numerical value of above-mentioned steps A8 and steps A 9 described filter coefficient α 1, α 2, and α 1＜α 2.The threshold value that above-mentioned steps A7 adopts is also determined by system emulation.
When in above-mentioned A7, judging whether to have sign mutation,, can select fast but the low filter of stability, otherwise select stable but the relatively poor filter of rapidity uses the above-mentioned filter that chooses to carry out filtering in step 10 if there is sign mutation.When selective filter, both can select finite impulse response filter (FIR), also can select IIR filter (IIR).
Fig. 7 is the example structure figure of device of the present invention.Multipath searching device shown in Figure 7 comprises despreading descrambling unit 41, peak filter 43, threshold judgement unit 44, also comprises energy calculation unit 110, the irrelevant unit 111 that adds up, filter factor determining unit 116 and each phase filtering unit 112, wherein:
Energy calculation unit 110 is used to finish the energy calculating to each phase signal of despreading descrambling element output signal correspondence, and result of calculation inputs to the irrelevant unit 111 that adds up;
The irrelevant unit 111 that adds up is used to finish the irrelevant of each signal phase energy and adds up, and accumulation result exports each phase filtering unit 112 and filter factor determining unit 116 to;
Filter factor determining unit 116 is used for determining the filter factor that each phase filtering unit uses according to the irrelevant signal corresponding phase that adds up unit 111 outputs;
Each phase filtering unit 112, be used for carrying out the filtering of each phase place of signal according to the signal corresponding phase signal of the irrelevant unit output that adds up and the filter factor of each phase signal that the filter factor determining unit is determined, this this example of unit is IIR filter (IIR).
Described filter factor determining unit 116 comprises Difference Calculation module 113, absolute calculation module 114 and filter factor selection module 115, with reference to figure 8.Wherein:
Filter factor is selected module 115, is used for determining according to the threshold value of absolute calculation module and regulation the filter factor of the corresponding phase of each phase filtering unit needs.
I, the Q two-way restituted signal function that is obtained each phase place by baseband signal finished in despreading descrambling unit 41, is input as the baseband signal of system, exports each phase place ground floor low-pass filter unit 120.
Based on the described device of above-mentioned Fig. 7, energy calculation unit 110 is finished the energy computing function to corresponding each phase place of each phase place despreading descrambling unit 41 output signal, inputs to the irrelevant unit 111 that adds up.The relevant accumulation function of each phase place energy is finished in the irrelevant unit 111 that adds up, and it is input as the output of energy calculation unit 110, and it exports each phase place IIR low-pass filter unit 112 and Difference Calculation module 113 to.Each phase place IIR low-pass filter unit 112 is finished and is chosen the output of some time-delays power spectrum corresponding phase according to filter factor determining unit 115, carry out IIR filtering, filtered time-delay power spectrum exports peak filter 43 to, by peak filter 43 filtered time-delay power spectrum, the peak value judgement is finished in the phase place of output peak value and energy to threshold judgement unit 44.Whether the threshold value threshold judgement timesharing position that threshold judgement unit 44 is finished according to peak energy and calculating is the function of multi-path location, the threshold value thresholding that it is input as peak phase and energy and calculates, it is output as the multipath phase place outside the present embodiment multipath, and the despreading descrambling unit 41 that arrives front-end processing.
Fig. 9 is the Difference Calculation modular structure figure that Fig. 8 adopts.Among Fig. 9, subtracter 120 is finished this input signal and is subtracted each other (calculating difference) work with energy signal last time.Wherein, last time energy signal was stored in the random access memory ram 121, and its address and read-write control signal are produced by address-generation unit 122 and control unit 123 respectively.Control unit 123 also produces the required address control signal of address-generation unit 122 simultaneously.Above-mentioned address-generation unit 122 and control unit 123 have constituted the controller of Difference Calculation module 113 jointly.
Subtracter 120 is finished input signal and the corresponding phase difference of energy signal (subtraction) calculation function last time that is stored among the RAM121, is input as input signal and energy signal last time, and the output differential signal is exported as system.RAM (121) finishes under address-generation unit 122 and control unit 123 controls, storage and the function of exporting the last time energy signal of each phase place correspondence, be input as the control signal of address-generation unit 122 read/write address signals and control unit 123, export last time energy signal to subtracter 120.Address-generation unit 122 is finished under the control of control unit 123, produces the function of the corresponding read/write address of RAM121, is input as the control signal of control unit 123, and output read/write address signal is to RAM121.
Control unit 123 is finished the sequencing control function to whole system, outputs control signals to RAM121 and address-generation unit 122.
Figure 10 is each phase filtering cellular construction figure that Fig. 7 adopts.Among Fig. 7, the output of each phase place IIR low-pass filter unit 112 by the product (finishing) of intake and filter coefficient α and output with multiplier 71 through time-delay (finishing) and coefficient 1-α (calculating) long-pending (finishing) with multiplier 72 by adder 130 by delay register 73 and (carrying out computing) by adder 74, subtracter 130 is finished the function of calculating 1-α.
Claims (8)
1, the multipath searching method in a kind of code division multiple access system comprises:
Step 1: baseband signal is carried out front-end processing, the I of each sampling phase correspondence of picked up signal, Q two paths of data;
Step 2: I, the Q two paths of data of each sampling phase correspondence that step 1 is obtained are handled respectively, obtain the energy of each sampling phase signal;
Step 3: the energy of each sampling phase signal that step 2 is obtained carries out the irrelevant of rear end and adds up, and obtains each sampling phase signal energy accumulation result;
Step 4: judge whether to exist sign mutation,, filter coefficient α=α 1 is set, otherwise filter coefficient α=α 2 is set if exist;
Wherein: α 1 is the less filter coefficient of predetermined numerical value; α 2 is the bigger filter coefficients of predetermined numerical value;
Step 5: to each sampling phase signal energy accumulation result that obtains in the step 3, the filter coefficient that adopts step 4 to determine according to the corresponding criterion of sampled point carries out filtering respectively, obtains the filtered signal energy of each sampling phase correspondence;
Step 6: the filtered signal energy of each sampling phase correspondence that obtains for step 5, carry out the multi-path location judgement, obtain and export the phase information of each multipath.
2, the multipath searching method in the code division multiple access system according to claim 1, it is characterized in that: described step 4 further comprises:
Step 41: for each sampling phase signal energy accumulation result that step 3 obtains, corresponding each phase place is carried out calculus of differences, output energy difference score value;
Step 42: the absolute value of the energy difference that obtains for step 41 carries out the threshold value judgement, if the absolute value absolute value of energy difference greater than threshold value then α=α 1, otherwise α=α 2;
3, the multipath searching method in the code division multiple access system according to claim 1 is characterized in that: adopt IIR filter (IIR) that each sampling phase signal energy accumulation result that obtains is carried out filtering in the step 5.
4, the multipath searching method in a kind of code division multiple access system comprises:
Steps A 1: baseband signal is carried out front-end processing, the I of each sampling phase correspondence of picked up signal, Q two paths of data;
Steps A 2: each sampling phase correspondence that steps A 1 is obtained I, Q two paths of data handle respectively, obtain the energy of each sampling phase signal;
Steps A 3: the energy of each sampling phase that steps A 2 is obtained carries out the irrelevant of rear end and adds up, and obtains each sampling phase signal energy accumulation result;
Steps A 4: judge whether to exist sign mutation,, select fast but the low filter of stability, otherwise select stable but the relatively poor filter of rapidity if exist;
Steps A 5: to each sampling phase signal energy accumulation result that obtains in the steps A 3, the filter that adopts steps A 4 to determine according to the corresponding criterion of sampled point carries out filtering respectively, obtains the filtered signal energy of each sampling phase correspondence;
Steps A 6: the filtered signal energy of each sampling phase correspondence that obtains for steps A 5, carry out the multi-path location judgement, obtain and export the phase information of each multipath.
5, the multipath searching device in a kind of code division multiple access system, comprise despreading descrambling unit, peak filter, threshold judgement unit, it is characterized in that, also comprise energy calculation unit, the irrelevant unit that adds up, filter factor determining unit and each phase filtering unit, wherein:
Energy calculation unit is used to finish the energy calculating to each phase signal of despreading descrambling element output signal correspondence, and result of calculation inputs to the irrelevant unit that adds up;
The irrelevant unit that adds up is used to finish the irrelevant of each signal phase energy and adds up, and accumulation result exports each phase filtering unit and filter factor determining unit to;
The filter factor determining unit is used for determining the filter factor that each phase filtering unit uses in corresponding phase according to the irrelevant signal that adds up unit output;
Each phase filtering unit is used for carrying out the filtering of each phase signal according to the corresponding phase signal of the irrelevant unit output that adds up and each phase filtering coefficient that the filter factor determining unit is determined.
6, the multipath searching method in the code division multiple access system according to claim 5 is characterized in that, described filter factor determining unit comprises Difference Calculation module, absolute calculation module and filter factor selection module, wherein:
The Difference Calculation module is used for choosing some time-delays power spectrum corresponding phase signal from the irrelevant signal that adds up unit output and carries out the signal energy calculus of differences, and operation result outputs to the absolute calculation module;
The absolute calculation module is used to finish the calculating of the absolute value of energy difference, and result of calculation outputs to filter factor and selects module;
Filter factor is selected module, is used for determining according to the threshold value of absolute calculation module and regulation the filter factor of the corresponding phase of each phase filtering unit needs.
According to the multipath searching method in claim 5 or the 6 described code division multiple access systems, it is characterized in that 7, described each phase filtering unit is IIR filter (IIR).
8, the multipath searching method in the code division multiple access system according to claim 6 is characterized in that, described Difference Calculation module comprises:
Subtracter is used to finish this input signal and the last time reducing mutually of energy signal;
Memory is used to store last time energy signal;
Controller is used for the last time signal data output of control storage.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100409589C (en) * | 2005-06-16 | 2008-08-06 | 中兴通讯股份有限公司 | Multipath searching method for broadband CDMA system |
| WO2008122153A1 (en) * | 2007-04-09 | 2008-10-16 | Masshall Limited | Dynamic multi-path detecting method and device in cdma communication system |
| CN1992542B (en) * | 2005-12-26 | 2011-05-11 | 中兴通讯股份有限公司 | Implementation method of multipath search in CDMA |
| US8340159B2 (en) | 2006-01-27 | 2012-12-25 | Thomson Licensing | Method and apparatus for multiresolution / multipath searcher |
| CN102904605A (en) * | 2012-09-25 | 2013-01-30 | 京信通信系统（中国）有限公司 | Method and device for determining multipath information and rake receiver |
| CN102958078A (en) * | 2011-08-31 | 2013-03-06 | 北京中电华大电子设计有限责任公司 | Method and device for processing abnormal signal in 802.11 baseband processor |
| CN105981304A (en) * | 2014-01-31 | 2016-09-28 | 高通股份有限公司 | A Low-Power Circuit And Implementation For Despreading On A Configurable Processor Datapath |
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| DE19623665C1 (en) * | 1996-06-13 | 1997-04-30 | Siemens Ag | Received signal mixture separation for multi-subscriber transmission |
| JP3274388B2 (en) * | 1997-07-25 | 2002-04-15 | 株式会社東芝 | RAKE receiver and spread spectrum communication apparatus provided with the RAKE receiver |
| CN1113495C (en) * | 2000-01-27 | 2003-07-02 | 华为技术有限公司 | Multipath search method and device for CDMA communication system |
| CN1150711C (en) * | 2001-08-15 | 2004-05-19 | 信息产业部电信传输研究所 | Adaptive predicting smoothing RAKE reception method and receiver |
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Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100409589C (en) * | 2005-06-16 | 2008-08-06 | 中兴通讯股份有限公司 | Multipath searching method for broadband CDMA system |
| CN1992542B (en) * | 2005-12-26 | 2011-05-11 | 中兴通讯股份有限公司 | Implementation method of multipath search in CDMA |
| US8340159B2 (en) | 2006-01-27 | 2012-12-25 | Thomson Licensing | Method and apparatus for multiresolution / multipath searcher |
| WO2008122153A1 (en) * | 2007-04-09 | 2008-10-16 | Masshall Limited | Dynamic multi-path detecting method and device in cdma communication system |
| CN102958078A (en) * | 2011-08-31 | 2013-03-06 | 北京中电华大电子设计有限责任公司 | Method and device for processing abnormal signal in 802.11 baseband processor |
| CN102904605A (en) * | 2012-09-25 | 2013-01-30 | 京信通信系统（中国）有限公司 | Method and device for determining multipath information and rake receiver |
| CN102904605B (en) * | 2012-09-25 | 2014-10-15 | 京信通信系统（中国）有限公司 | Method and device for determining multipath information and rake receiver |
| CN105981304A (en) * | 2014-01-31 | 2016-09-28 | 高通股份有限公司 | A Low-Power Circuit And Implementation For Despreading On A Configurable Processor Datapath |
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