CN103546190A - Method for searching for downlink synchronous codes and user equipment - Google Patents
Method for searching for downlink synchronous codes and user equipment Download PDFInfo
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Abstract
The embodiment of the invention provides a method for searching for downlink synchronous codes and user equipment. The method is used for reducing the calculation amount for searching for the downlink synchronous codes and is high in searching accuracy. According to the method, a cell signal is received in advance. The method comprises the steps that a sample signal of the cell signal is determined; binarization processing is conducted on a value of each sampling point in the sample signal; each inflection point in the sample signal after binarization processing is conducted is determined; each inflection point comprises a sampling point jumped from 0 to 1 and a sampling point jumped from 1 to 0 in the binarized signal; according to the distance between the inflection points, the positions of the downlink synchronous codes are determined.
Description
Technical field
The present invention relates to moving communicating field, relate in particular to a kind of method and subscriber equipment of searching downlink synchronous code.
Background technology
In mobile communication system, after terminal powers on, need to search the community that it may exist around, and select suitable community login, can intercept afterwards the paging on network or make a call connecting, above process is called cell initial search (Initial Cell Search, ICS).Before terminal login community, needed wave point synchronizing process ，Yu community to set up synchronous.
At global system for mobile communications (Global System for Mobile communication, GSM) and Wideband Code Division Multiple Access (WCDMA) access (Wideband Code Division Multiple Access, WCDMA) in system, there is a public synchronous code, as subscriber equipment (User Equipment, while UE) this synchronous code being detected, ，Jiu Nengyu community is set up synchronous.And there is not similar common synchronization code in the systems such as TD SDMA access (Time Division Synchronous CDMA, TD-SCDMA).In this type systematic, a plurality of mutually orthogonal descending synchronous codes (synchronous downlink, SYNC_DL) are used in neighbor cell, therefore, need to detect the position of SYNC_DL, could resolve SYNC_DL and select suitable community login.
The scheme of determining at present SYNC_DL position mainly contains the full comparison method of full search, Window search method, and the search method based on frame structure.
The full comparison method of full search: mainly comprise the time domain full comparison method of full search and two kinds of methods of the frequency domain full comparison method of full search, its principle is maximum likelihood (the Maximum Lilehood of standard, ML) detect, be that to take a chip (chip) be step-length to UE, the signal of receiving and all possible 32 SYNC_DL are carried out related calculation, and choosing the corresponding sequence of maximum is SYNC_DL.For whole subframe 6400chip, directly search and be referred to as full search, and often search a chip, just make comparisons with 32 SYNC_DL sequences more, be referred to as full comparison.
Window search method: Fig. 1 has provided the basic principle of Window search method, it mainly the matching criterior based on certain search the descending pilot frequency time slot (Downlink Pilot Time Slot, DwPTS) at SYNC_DL place.Its principle is, Moving Window length is the Window of 8 symbols (Symbol), calculate the power summation Pinner of 4 middle Symbol of window and power and the Pside of each 2 Symbol of window both sides, and calculate its ratio P=Pside/Pinner, when P is min(P) time, can be according to the position of the location positioning DwPTS of this moment Window.
Search method based on frame structure: according to the frame structure definition of TD-SCDMA, there is the GP of certain length the front and back of SYNC_DL, under ideal conditions, in GP, the signal of transmitting is continuous logical zero, SYNC_DL sequence is different " 0～1 " sequence, pertinent literature has provided the method for another kind of search SYNC_DL based on this basis: due to SYNC_DL, uplink synchronous code (synchronous uplink, SYNC_UL) and intermediate code (Midamble) do not need spread spectrum, also without scrambling, process, therefore the output signal that can directly get matched filter is analyzed, its cardinal principle is to utilize respectively counter to logical zero and logical one counting, when receiving continuously the logical zero of 96chip, can determine that this position is GP between GP(SYNC_DL after SYNC_DL sequence and SYNC_UL), with this, in next subframe, find the position of SYNC_DL sequence, then it is done to coherent detection can obtain SYNC_DL sequence.
Prior art major defect is:
The full comparison method of full search of time domain, frequency domain is in global scope, to do relevant search, although its disposable accuracy of setting up down-going synchronous is high, amount of calculation is too large; Window search method, the search method based on frame structure are intended in advance the location positioning of SYNC_DL or dwindle its scope, thereby remake subsequently correlation computations and correctly demodulate SYNC_DL, although reduced computation complexity, still improve circuit complexity, also sacrificed the success rate of a part of demodulation.
Summary of the invention
The embodiment of the present invention provides a kind of method and subscriber equipment of searching downlink synchronous code, for reducing searching downlink synchronous code amount of calculation, and there is higher search precision.
The concrete technical scheme that the embodiment of the present invention provides is as follows:
First aspect, a kind of method of searching downlink synchronous code, receives cell signal in advance, and the method comprises:
Determine the sample signal of cell signal;
Value to each sampled point in described sample signal is carried out binary conversion treatment;
Determine each flex point in the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step;
According to the distance between each flex point, determine the position of descending synchronous code.
Distance between next flex point after each flex point and this flex point has embodied the subframe structure feature of sample signal, and like this, subscriber equipment basis can be according to subframe structure signature search descending synchronous code, and search procedure is calculated simple, and precision is high.
In conjunction with first aspect, in the possible implementation of the first,
Described according to the distance between each flex point, determine the position of descending synchronous code, specifically comprise:
According to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range; Wherein, described predeterminable range is according to the structure of time slot of descending pilot frequency time slot, to determine in advance;
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending synchronous code.
In conjunction with the possible implementation of the first of first aspect, in the possible implementation of the second, according to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending synchronous code, comprising:
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot;
According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.
In conjunction with the possible implementation of the first of first aspect, in the third possible implementation, described according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range, specifically comprise:
According to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance;
From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
In conjunction with first aspect, in the 4th kind of possible implementation, the sample signal of described definite cell signal, comprising:
By the data of a subframe lengths in described cell signal, be defined as the sample signal of described cell signal.
In conjunction with the 4th kind of possible implementation of first aspect, in the 5th kind of possible implementation, the method further comprises:
Data to a subframe lengths in described cell signal are carried out down-sampling processing, obtain the sample signal of described cell signal.
Like this, through the down-sampling of certain multiple, process, reduced signal data amount, further reduced computation complexity.
In conjunction with the 5th kind of possible implementation of first aspect, in the 6th kind of possible implementation, before the data of a subframe lengths in described cell signal are carried out to down-sampling processing, the method also comprises:
Data to a subframe lengths in described cell signal are carried out the disposal of gentle filter.
Like this, effectively suppressed the burr in noise and signal, further, the noise while having reduced follow-up binary conversion treatment and signal pulse disturb.
In conjunction with first aspect, in the 7th kind of possible implementation, the value of each sampled point in described sample signal is carried out to binary conversion treatment, specifically comprise:
In described sample signal, the value of each sampled point, choose the maximum occurrences of default the first number, according to the maximum occurrences of described default the first number, calculate the power characterization value of described sample signal; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community;
According to described power characterization value, be identified for the threshold value of binary conversion treatment;
According to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment.
Like this, threshold value must be to obtain according to the power statistic of useful signal, has guaranteed the effect of binary conversion treatment.
In conjunction with the 7th kind of possible implementation of first aspect, in the 8th kind of possible implementation, according to the maximum occurrences of described default the first number, calculate the power characterization value of described sample signal, specifically comprise:
Determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
In conjunction with the 7th kind of possible implementation of first aspect, in the 9th kind of possible implementation, according to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment, specifically comprise:
When the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2;
The value of remaining sampled point in described sample signal is designated as to 1.
Like this, filtering the interference of low-power signal, reduced flex point quantity.
Second aspect, a kind of subscriber equipment, this equipment comprises:
Receiving element, for receiving in advance cell signal;
Sample signal determining unit, for determining the sample signal of cell signal;
Binary conversion treatment unit, for carrying out binary conversion treatment to the value of each sampled point in described sample signal;
Flex point determining unit, for determining each flex point of the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step;
Position determination unit, for according to the distance between each flex point, determines the position of descending synchronous code.
Distance between next flex point after each flex point and this flex point has embodied the subframe structure feature of sample signal, and like this, subscriber equipment basis can be according to subframe structure signature search descending synchronous code, and search procedure is calculated simple, and precision is high.
In conjunction with second aspect, in the possible implementation of the first, described position determination unit, specifically comprises:
Metrics calculation unit, for according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range; Wherein, described predeterminable range is according to the structure of time slot of descending pilot frequency time slot, to determine in advance;
Position of downlink synchronous code determining unit, for according to the distance between described and next flex point close to the flex point of predeterminable range, determine the position of descending synchronous code.
In conjunction with the possible implementation of the first of second aspect, in the possible implementation of the second,, described position of downlink synchronous code determining unit, specifically for:
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot;
According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.
In conjunction with the possible implementation of the first of second aspect, in the third possible implementation, described metrics calculation unit, specifically for:
According to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance;
From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
In conjunction with second aspect, in the 4th kind of possible implementation, described sample signal determining unit, specifically for:
By the data of a subframe lengths in described cell signal, be defined as the sample signal of described cell signal.
In conjunction with the 4th kind of possible implementation of second aspect, in the 5th kind of possible implementation, described sample signal determining unit, is further used for:
Data to a subframe lengths in described cell signal are carried out down-sampling processing, obtain the sample signal of described cell signal.
Like this, through the down-sampling of certain multiple, process, reduced signal data amount, further reduced computation complexity.
In conjunction with the 5th kind of possible implementation of second aspect, in the 6th kind of possible implementation, described sample signal determining unit also for:
Before the data of a subframe lengths are carried out down-sampling processing in to described cell signal, the data of a subframe lengths in described cell signal are carried out to the disposal of gentle filter.
Like this, effectively suppressed the burr in noise and signal, further, the noise while having reduced follow-up binary conversion treatment and signal pulse disturb.
In conjunction with second aspect, in the 7th kind of possible implementation, described binary conversion treatment unit, comprising:
Useful signal power calculation unit, chooses the maximum occurrences of presetting the first number for the value of each sampled point in described sample signal, calculate the power characterization value of described sample signal according to the maximum occurrences of described default the first number; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community;
Threshold calculations unit, for according to described power characterization value, is identified for the threshold value of binary conversion treatment;
Binarization unit, for carrying out binary conversion treatment according to described threshold value to the value of each sampled point in described sample signal.
Like this, threshold value must be to obtain according to the power statistic of useful signal, has guaranteed the effect of binary conversion treatment.
In conjunction with the 7th kind of possible implementation of second aspect, in the 8th kind of possible implementation, when described useful signal power calculation unit is used for calculating the power characterization value of described sample signal according to the maximum occurrences of described default the first number, specifically for:
Determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
In conjunction with the 7th kind of possible implementation of second aspect, in the 9th kind of possible implementation, described binarization unit specifically for:
When the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2;
The value of remaining sampled point in described sample signal is designated as to 1.
Like this, filtering the interference of low-power signal, reduced flex point quantity.
Accompanying drawing explanation
Fig. 1 is the principle schematic of Window search method in prior art;
Fig. 2 is the schematic flow sheet of the method for a kind of searching downlink synchronous code of providing of the embodiment of the present invention;
Fig. 3 is a subframe structure schematic diagram of TD-SCDMA system;
Fig. 4 is the structural representation of DwPTS;
There is not the effect schematic diagram after a sub-frame data binary conversion treatment while disturbing in Fig. 5;
Fig. 6 is the schematic flow sheet of the method for a kind of searching downlink synchronous code of providing of the specific embodiment of the invention;
Fig. 7 is the signal waveforms of the cell signal that obtains in the specific embodiment of the invention;
Fig. 8 is the oscillogram of integrating in the specific embodiment of the invention after two paths of signals;
Fig. 9 is to the oscillogram after sample signal smothing filtering in the specific embodiment of the invention;
Figure 10 carries out 10 times of oscillograms after down-sampling to sample signal in the specific embodiment of the invention;
Figure 11 is the oscillogram of getting in the specific embodiment of the invention after front 15% data;
Figure 12 carries out the oscillogram after binary conversion treatment to sample signal in the specific embodiment of the invention;
Figure 13 is the schematic diagram of the flex point of each after binary conversion treatment and flex point spacing in the specific embodiment of the invention;
Figure 14 is the structural representation of a kind of subscriber equipment of providing of the embodiment of the present invention.
Embodiment
The embodiment of the present invention provides a kind of method and subscriber equipment of searching downlink synchronous code, for reducing the amount of calculation of searching downlink synchronous code, and has higher search precision, has improved the efficiency of definite position of downlink synchronous code.
The embodiment of the present invention, can be applied to use between arbitrary each community the system of different synchronous codes, and this type systematic includes but not limited to TD-SCDMA system.
Below in conjunction with accompanying drawing, the preferential execution mode of the present invention is elaborated.
The method of a kind of searching downlink synchronous code that as shown in Figure 2, the embodiment of the present invention provides comprises:
S201, receive cell signal in advance.
Community can be used any modulation system to modulate and send data-signal.And receive the data-signal from community by UE.The data-signal receiving from community, can be TD-SCDMA community.
S202, determine the sample signal of cell signal.
By the data of a subframe lengths in described cell signal, be defined as the sample signal of described cell signal.
Particularly, when community, signal is carried out to serial to parallel conversion and obtain two-way orthogonal signalling transmission, adopt Quadrature Phase Shift Keying (Quadrature Phase ShiftKeying, QPSK), 8 phase-shift keyings (Phase ShiftKeying, PSK), 16 quadrature amplitude modulation (Quadrature Amplitude Modulation, QAM) etc. during modulation system, first receiving terminal need to merge to process to two paths of signals and obtain a road signal, to reduce amount of calculation.
Further, S202 specifically comprises: the data to a subframe lengths in described cell signal are carried out down-sampling processing, obtain the sample signal of described cell signal.The down-sampling that UE carries out certain multiple to cell signal is processed, and can effectively reduce amount of calculation.Obviously, down-sampling multiple is more, and amount of calculation is fewer, but the precision of search also can decrease.
Further, before the data of a subframe lengths in described cell signal are carried out to down-sampling processing, the method also comprises: the data to a subframe lengths in described cell signal are carried out the disposal of gentle filter.By smothing filtering, suppress the burr in noise and signal, the noise while reducing follow-up binary conversion treatment and signal pulse disturb.
S203, the value of each sampled point in described sample signal is carried out to binary conversion treatment.
The value of each sampled point of sample signal is carried out to binary conversion treatment, and it is 0 or 1 that the value that is about to each sampled point of sample signal redefines, and sample signal is converted into and only includes the architectural feature that 0 and 1 sequence is convenient to obtain sample signal.
Further, value to each sampled point in described sample signal is carried out binary conversion treatment, specifically comprise: in described sample signal, the value of each sampled point, choose the maximum occurrences of default the first number, according to the maximum occurrences of described default the first number, calculate the power characterization value of described sample signal; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community; According to described power characterization value, be identified for the threshold value of binary conversion treatment; According to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment.
The minimum downlink data amount of the single subframe of community can determine,, no matter use which kind of time slot configuration, at least on a part of time slot, community is bound to send downlink data.The power characterization value of determining according to the data on this part of time slot, than the average power of the whole subframe of direct calculating, the power closer to community when normally sending data-signal.
After the power characterization value of definite sample signal, between power characterization value and 0, choose the threshold value that a numerical value is defined as binary conversion treatment, due to disturbing factor, GP can be slightly larger than 0, for GP is showed with 0 as far as possible, and avoid the part beyond GP to represent with 0, getting threshold value is 0.04 to 0.2 of power characterization value as far as possible.
Further, according to the maximum occurrences of described default the first number, calculate the power characterization value of described sample signal, specifically comprise: determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
Further, according to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment, specifically comprise: when the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2; The value of remaining sampled point in described sample signal is designated as to 1.
Owing to disturbing and signal self reason, the part beyond GP is certain to have the sampled point that is less than threshold value, but this type of sampled point often only can discrete appearance.Therefore, the sampled point that only continuous a plurality of values is less than to threshold value is designated as 0, can reduce the appearance of flex point, reduces unnecessary amount of calculation.
S204, determine each flex point in the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step.
S205, according to the distance between each flex point, determine the position of descending synchronous code.
The power of the GP of sample signal should be 0 entirely in theory, the power that the interior descending synchronous code of sample signal etc. includes the data of effective information is not 0, here be designated as 1, because the position of synchronous code in each subframe is fixed, subframe structure before and after synchronous code is similar, arbitrary subframe signal is when representing with 0,1, and 0 has some identical features with 1 distribution.By adding up the distance between each flex point, find the flex point that meets these same characteristic features, just can determine the position of descending synchronous code.
Further, S205 specifically comprises: according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range; Wherein, described predeterminable range is according to the structure of time slot of descending pilot frequency time slot, to determine in advance; According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot; According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.Be the descending pilot frequency time slot at first searching downlink synchronous code place, then searching downlink synchronous code.
Further, described according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range, specifically comprise: according to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance; From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
Particularly, according to a time slot before descending pilot frequency time slot, determine the first scope, according to the structure of time slot of descending pilot frequency time slot, determine the second scope, according to the protection interval between descending pilot frequency time slot and uplink pilot time slot, determine the 3rd scope.By the structure of time slot feature of subframe, determine above constraints and flex point is carried out to Preliminary screening, can improve the precision of search.
Below in conjunction with specific embodiment, be described further.
The length of each subframe of TD-SCDMA system is fixed as 6400 chips (chip); include 3 special time slots; respectively DwPTS; protection interval (Guard Period; GP) and uplink pilot time slot (Uplink Pilot Time Slot; UpPTS), DwPTS is comprised of GP and SYNC_DL.System definition 32 code characters, every group of corresponding SYNC_DL sequence.The location positioning of SYNC_DL in each subframe, every 5ms sends once in down link data.
As shown in Figure 3, be the subframe structure schematic diagram of the time slot configuration scheme that adopts in this specific embodiment, wherein, descending pilot frequency time slot comprises 96 chip, and protection interval comprises 96 chip, and uplink pilot time slot comprises 160 chip.DwPTS comprises GP and SYNC_DL, is respectively 32 chip and 64 chip, and its structure as shown in Figure 4.
Community at least sends downlink data in first time slot (TS0) and DwPTS, account for about 15% of whole slot length, therefore, when the roughly power of the normal transmitted signal of calculation plot is power characterization value, according to approaching or equaling 15% ratio, choose sample signal and calculate, determine the threshold value of binaryzation.
And, signal to be carried out after binary conversion treatment, the problem of search DwPTS can be converted near the problem of special flex point search DwPTS.As shown in Figure 5, in conjunction with the actual effect of emulation, when not there is not any interference, there is following feature in this special flex point obj_point:
1, the value of flex point is 0;
2, the distance of obj_point and obj_point left side flex point is 864chip;
3, the distance of obj_point and first flex point of obj_point the right is 48chip;
4, the distance of obj_point first flex point of the right and obj_point second right flex point is 64chip, and the data of these 64 chip are SYNC_DL;
5, the distance of obj_point second right flex point and obj_point third right flex point is at least 64chip.
According to above feature, determine the constraints of obj_point and search in flex point, just can determine DwPTS position.
In TD-SCDMA system, the complete step of UE search SYNC_DL as shown in Figure 6, specifically comprises following content:
S601, obtain mutually orthogonal modulation signal I (i) and the Q (i) of two-way that community one frame time sends simultaneously, as shown in Figure 7;
S602, integration two paths of signals, obtain a road sample data
, ask two paths of data absolute value and, as shown in Figure 8;
S603, sample data is carried out to smothing filtering, filtering result as shown in Figure 9;
S604, sample signal is carried out to 10 times of down-samplings, after down-sampling, sample size is 640, as shown in figure 10;
S605, according to size sequence, take out the large end of sample signal front 15% and be the data of 96, as shown in figure 11;
The mean value of the data of S606, calculating front 15%, this mean value characterizes the power of current demand signal;
S607, this mean value is multiplied by 0.15, as the threshold value of binary conversion treatment;
S608, the sample signal before utilizing state machine to down-sampling carry out binary conversion treatment, only continuous, 4 and the above point that is less than threshold value are set to 0, and obtaining at least 272 is 0 sampled point, accounts for 4% of sequence, as shown in figure 12;
S609, determine each flex point (point), and each flex point spacing (len), as shown in figure 13;
S610, the default constraint of basis are searched for, and corner position is to meet constraint at 4020 o'clock, determines DwPTS position;
Constraint content is determined according to obj_point feature, arranges as follows:
What make that abs (len (k+1)-48) gets minimum value is 0 flex point; Or, make abs (len (k)-864) <30, in the flex point of abs (len (k+2)-64) <10 and abs (len (k+3)) >64, what make that abs (len (k+1)-48) gets minimum value is 0 flex point; Wherein, abs is for asking absolute value.
S611, according to DwPTS position further search determine the position of SYNC_DL.
As shown in figure 14, a kind of subscriber equipment that the embodiment of the present invention provides comprises:
Receiving element 1401, for receiving in advance cell signal;
Sample signal determining unit 1402, for determining the sample signal of cell signal;
Binary conversion treatment unit 1403, for carrying out binary conversion treatment to the value of each sampled point in described sample signal;
Flex point determining unit 1404, for determining each flex point of the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step;
Further, described position determination unit 1405, specifically comprises:
Position of downlink synchronous code determining unit 1425, for according to the distance between described and next flex point close to the flex point of predeterminable range, determine the position of descending synchronous code.
Further, described position of downlink synchronous code determining unit 1425, specifically for:
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot;
According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.
Further, described metrics calculation unit 1415, specifically for: according to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance;
From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
Described sample signal determining unit 1402, specifically for data to a subframe lengths in described cell signal, is defined as the sample signal of described cell signal.
Further, described sample signal determining unit 1402, for the data of a subframe lengths of described cell signal are carried out to down-sampling processing, obtains the sample signal of described cell signal.
Further, described sample signal determining unit 1402 also for: before the data of a subframe lengths of described cell signal are carried out to down-sampling processing, the data of a subframe lengths in described cell signal are carried out to the disposal of gentle filter.
Further, described binary conversion treatment unit 1403, comprising:
Useful signal power calculation unit 1413, chooses the maximum occurrences of presetting the first number for the value of each sampled point in described sample signal, calculate the power characterization value of described sample signal according to the maximum occurrences of described default the first number; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community;
Further, described useful signal power calculation unit 1413 is when calculating the power characterization value of described sample signal according to the maximum occurrences of described default the first number, specifically for: determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
Further, described binarization unit 1433 specifically for: when the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2; The value of remaining sampled point in described sample signal is designated as to 1.
In sum, the embodiment of the present invention provides a kind of method and subscriber equipment of searching downlink synchronous code, is applied to Radio Network System, method than prior art, amount of calculation is low, and circuit is realized simple, and has higher search precision and be demodulated to power.
Those skilled in the art should understand, embodiments of the invention can be provided as method, system or computer program.Therefore, the present invention can adopt complete hardware implementation example, implement software example or in conjunction with the form of the embodiment of software and hardware aspect completely.And the present invention can adopt the form that wherein includes the upper computer program of implementing of computer-usable storage medium (including but not limited to magnetic disc store and optical memory etc.) of computer usable program code one or more.
The present invention is with reference to describing according to flow chart and/or the block diagram of the method for the embodiment of the present invention, equipment (system) and computer program.Should understand can be in computer program instructions realization flow figure and/or block diagram each flow process and/or the flow process in square frame and flow chart and/or block diagram and/or the combination of square frame.Can provide these computer program instructions to the processor of all-purpose computer, special-purpose computer, Embedded Processor or other programmable data processing device to produce a machine, the instruction of carrying out by the processor of computer or other programmable data processing device is produced for realizing the device in the function of flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame appointments.
These computer program instructions also can be stored in energy vectoring computer or the computer-readable memory of other programmable data processing device with ad hoc fashion work, the instruction that makes to be stored in this computer-readable memory produces the manufacture that comprises command device, and this command device is realized the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame.
These computer program instructions also can be loaded in computer or other programmable data processing device, make to carry out sequence of operations step to produce computer implemented processing on computer or other programmable devices, thereby the instruction of carrying out is provided for realizing the step of the function of appointment in flow process of flow chart or a plurality of flow process and/or square frame of block diagram or a plurality of square frame on computer or other programmable devices.
Obviously, those skilled in the art can carry out various changes and modification and not depart from the spirit and scope of the present invention the present invention.Like this, if within of the present invention these are revised and modification belongs to the scope of the claims in the present invention and equivalent technologies thereof, the present invention is also intended to comprise these changes and modification interior.
Claims (20)
1. a method for searching downlink synchronous code, is characterized in that, receives in advance cell signal, and the method comprises:
Determine the sample signal of cell signal;
Value to each sampled point in described sample signal is carried out binary conversion treatment;
Determine each flex point in the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step;
According to the distance between each flex point, determine the position of descending synchronous code.
2. the method for claim 1, is characterized in that, described according to the distance between each flex point, determines the position of descending synchronous code, specifically comprises:
According to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range; Wherein, described predeterminable range is according to the structure of time slot of descending pilot frequency time slot, to determine in advance;
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending synchronous code.
3. method as claimed in claim 2, is characterized in that, according to the distance between described and next flex point, close to the flex point of predeterminable range, determines the position of descending synchronous code, comprising:
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot;
According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.
4. method as claimed in claim 2, is characterized in that, described according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range, specifically comprise:
According to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance;
From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
5. the method for claim 1, is characterized in that, the sample signal of described definite cell signal, comprising:
By the data of a subframe lengths in described cell signal, be defined as the sample signal of described cell signal.
6. method as claimed in claim 5, is characterized in that, further comprises:
Data to a subframe lengths in described cell signal are carried out down-sampling processing, obtain the sample signal of described cell signal.
7. method as claimed in claim 6, is characterized in that, before the data of a subframe lengths in described cell signal are carried out to down-sampling processing, the method also comprises:
Data to a subframe lengths in described cell signal are carried out the disposal of gentle filter.
8. the method for claim 1, is characterized in that, the value of each sampled point in described sample signal is carried out to binary conversion treatment, specifically comprises:
In described sample signal, the value of each sampled point, choose the maximum occurrences of default the first number, according to the maximum occurrences of described default the first number, calculate the power characterization value of described sample signal; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community;
According to described power characterization value, be identified for the threshold value of binary conversion treatment;
According to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment.
9. method as claimed in claim 8, is characterized in that, calculates the power characterization value of described sample signal according to the maximum occurrences of described default the first number, specifically comprises:
Determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
10. method as claimed in claim 8, is characterized in that, according to described threshold value, the value of each sampled point in described sample signal is carried out to binary conversion treatment, specifically comprises:
When the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2;
The value of remaining sampled point in described sample signal is designated as to 1.
11. 1 kinds of subscriber equipmenies, is characterized in that, this equipment comprises:
Receiving element, for receiving in advance cell signal;
Sample signal determining unit, for determining the sample signal of cell signal;
Binary conversion treatment unit, for carrying out binary conversion treatment to the value of each sampled point in described sample signal;
Flex point determining unit, for determining each flex point of the described sample signal after binary conversion treatment; The sampled point that it is 1 by 0 saltus step that described flex point comprises in the signal of binaryzation, and the sampled point that is 0 by 1 saltus step;
Position determination unit, for according to the distance between each flex point, determines the position of descending synchronous code.
12. equipment as claimed in claim 11, is characterized in that, described position determination unit, specifically comprises:
Metrics calculation unit, for according to the distance between the next flex point after each flex point and this flex point, determine and next flex point between distance close to the flex point of predeterminable range; Wherein, described predeterminable range is according to the structure of time slot of descending pilot frequency time slot, to determine in advance;
Position of downlink synchronous code determining unit, for according to the distance between described and next flex point close to the flex point of predeterminable range, determine the position of descending synchronous code.
13. equipment as claimed in claim 12, is characterized in that, described position of downlink synchronous code determining unit, specifically for:
According to the distance between described and next flex point, close to the flex point of predeterminable range, determine the position of descending pilot frequency time slot;
According to the position of described descending pilot frequency time slot, determine the position of descending synchronous code.
14. equipment as claimed in claim 12, is characterized in that, described metrics calculation unit, specifically for:
According to the distance between the next flex point after each flex point and this flex point, choose and meet pre-conditioned flex point; Described pre-conditioned, comprising: the distance between the upper flex point before selected flex point and this flex point is in default the first scope; And the next flex point after this flex point and the distance between second flex point after this flex point are in default the second scope; And second flex point after this flex point and the distance between the 3rd flex point after this flex point are in default the 3rd scope; Wherein, described default the first scope, default the second scope and default the 3rd scope are according to the structure of time slot of cell signal, to determine in advance;
From described meet pre-conditioned flex point, choose and next flex point between distance close to the flex point of predeterminable range.
15. equipment as claimed in claim 11, is characterized in that, described sample signal determining unit, specifically for:
By the data of a subframe lengths in described cell signal, be defined as the sample signal of described cell signal.
16. equipment as claimed in claim 15, is characterized in that, described sample signal determining unit, is further used for:
Data to a subframe lengths in described cell signal are carried out down-sampling processing, obtain the sample signal of described cell signal.
17. equipment as claimed in claim 16, is characterized in that, described sample signal determining unit also for:
Before the data of a subframe lengths are carried out down-sampling processing in to described cell signal, the data of a subframe lengths in described cell signal are carried out to the disposal of gentle filter.
18. equipment as claimed in claim 11, is characterized in that, described binary conversion treatment unit, comprising:
Useful signal power calculation unit, chooses the maximum occurrences of presetting the first number for the value of each sampled point in described sample signal, calculate the power characterization value of described sample signal according to the maximum occurrences of described default the first number; Wherein, described default the first number is to determine according to the minimum downlink data amount of the single subframe of described community;
Threshold calculations unit, for according to described power characterization value, is identified for the threshold value of binary conversion treatment;
Binarization unit, for carrying out binary conversion treatment according to described threshold value to the value of each sampled point in described sample signal.
19. equipment as claimed in claim 18, is characterized in that, when described useful signal power calculation unit is used for calculating the power characterization value of described sample signal according to the maximum occurrences of described default the first number, specifically for:
Determine the mean value of the maximum occurrences of described default the first number, the power characterization value that described mean value is described sample signal.
20. equipment as claimed in claim 18, is characterized in that, described binarization unit specifically for:
When the value of the continuous sampled point of at least default the second number is all less than described threshold value in determining described sample signal, the value of described continuous sampled point is all designated as to 0; Described default the second number is more than or equal to 2;
The value of remaining sampled point in described sample signal is designated as to 1.
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