CN103095625B - Scramble initial value collocation method - Google Patents

Abstract

The invention provides a scramble initial value collocation method which is used in a system with discontinuous work frequency ranges. The method comprises that when scramble initial value needs to be set for a sub-band, the formula that x1(0) = 1, x1(n) = 0, n = 1, 2, ... , 30 is used, the first m sequence x1( ) used for generating a scramble sequence is initialized, and according to a sub-band reference number and a community identification number of the sub-band, the second m sequence x2() used for generating the scramble sequence is initialized. By means of the scramble initial value collocation method, time-domain signal peak-to-average ratio of the system with discontinuous spectral bandwidths can be lowered.

Description

A kind of collocation method of scramble initial value

Technical field

The present invention relates to the resource configuration technology in mobile communication system, particularly relate to a kind of collocation method of scramble initial value.

Background technology

Scrambler can make digital transmission system have the transparency to various digital information, makes randomization by binary digital information, makes signal spectrum disperse and keeps steady.In 3GPP Long Term Evolution (LTE) system, the scrambler to each physical channel design, uses the characteristic of scrambler to reduce interfering with each other of signal between community.For descending control format indicating channel (PCFICH), in each subframe, by the OFDM number that CFI (control format instruction) indicates PDCCH in this subframe to take, CFI carries out chnnel coding 32 bit according to the table 5.3.4-1 of 3GPP agreement 36.212860 version.

Bit block b (0) after coding ..., b (31) uses cell specific scrambling code sequence to carry out scrambling, forms the bit block of scrambling namely $\tilde{b}\left(i\right)+(b\left(i\right)+c\left(i\right))\mathrm{mod}2$

Wherein, scramble sequence c (i) use length be 31 Gold sequence generate, length is M _pNpseudo random sequence c (n), n=0,1 ..., M _pN-1 is defined as

c(n)＝(x ₁(n+N _C)+x ₂(n+N _C))mod 2

x ₁(n+31)＝(x ₁(n+3)+x ₁(n))mod 2

x ₂(n+31)＝(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n))mod 2

Wherein N _c=1600, first m sequence x ₁() is by x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30 carry out initialization, second m sequence x ₂() by carry out initialization, the initialization value c of this sequence _initinitialization is carried out according to the following formula when every frame starts:

Wherein, n _srepresent the timeslot number of a radio frames, represent community ID.

Because each subframe in each community only has a PCFICH, and only account for 4 REG, and in actual applications, the PCFICH of different districts may be mapped on identical resource location, in the case, by using different scramblers, can reach and reduce the object that between community, PCFICH interferes with each other.

3GPP Long Term Evolution (LTE) system descending control format indicating channel distributes in whole system bandwidth, and a subframe only has a PCFICH channel, therefore, in above-mentioned existing PCFICH scrambling code sequence generation method, scramble initial value is set and only considered timeslot number in radio frames and physical-layer cell ID, reduce to be reached by scrambling the object that between community, control signal interferes with each other.

And private network communication system takies discontinuous spectral bandwidth usually, each 25kHz is a subband, hold at eNodeB, each subband has PCFICH channel, take identical resource location, each subband carries out separately IFFT and generates time-domain signal, carries out the superposition of time domain, then sent by antenna port after being then modulated on corresponding carrier frequency.

In actual applications, often there will be the situation that codeword information that on multiple subband, control channel carries is identical, now, if adopt above-mentioned LTE control channel disturb code generating method, then can produce identical scramble sequence.Like this, before carrying out IFFT conversion, multiple subband can generate identical frequency-region signal (f ₁, f ₂... f _n), so through IFFT, filter filtering after being modulated to respective carrier frequency, the time-domain signal signal of synthesis can be similar to and represent with following formula:

$\mathrm{signal}(\mathrm{1,2},..,N)=\mathrm{ifft}(f_1,f_1...f_N)*e^{-j2\mathrm{\π}{f}_0/f_s*(\mathrm{1,2},...,N)}$

$+\mathrm{ifft}(f_1,f_1...f_N)*e^{-j2\mathrm{\π}{f}_1/f_s*(\mathrm{1,2},...,N)}+...+\mathrm{ifft}(f_1,f_1...f_N)*e^{-j2\mathrm{\π}{f}_{\mathrm{TotalSubBand}}/f_s*(\mathrm{1,2},...,N)}$

$=\mathrm{ifft}(f_1,f_1...f_N)*e^{-j2\mathrm{\π}*(\mathrm{1,2},...,N)}(e^{f_0/f_s}+e^{f_1{/f}_s}+...+e^{f_{\mathrm{TotalSubBand}}/f_s})$

Wherein, TotalSubBand is sub band number.

As can be seen from formula above, when sub band number is very large, very high peak-to-average force ratio (PAPR) can be caused, and then affect the tranception-quality of signal

Summary of the invention

In view of this, main purpose of the present invention is the collocation method providing a kind of scramble initial value, and the method can reduce the time-domain signal peak-to-average force ratio of spectral bandwidth discontinuous system.

In order to achieve the above object, the technical scheme that the present invention proposes is:

A collocation method for scramble initial value, the method is used for, in the discontinuous system of working frequency range, comprising the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂().

In sum, the collocation method of the scramble initial value that the present invention proposes, subband number is introduced when generating scrambler, different scrambler sequence initial values is arranged to different sub-band, thus different scrambler sequence can be produced on this basis, make the time domain data randomization on multiple subband, reach the object reducing peak-to-average force ratio.

Embodiment

For making the object, technical solutions and advantages of the present invention clearly, below in conjunction with specific embodiment, the present invention is described in further detail.

Core concept of the present invention is: for the discontinuous system of working frequency range, when carrying out scrambler initial value to control channel and Traffic Channel and arranging, introduce subband number, in order to produce different scrambler sequence to different sub-band, make the time domain data randomization on multiple subband, like this, after being modulated to respective carrier frequency and carrying out conjunction road, the peak-to-average force ratio of the time-domain signal of generation just can reduce.

The embodiment of the present invention one mainly comprises the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂().

In said method, carry out initialization for generating second m sequence x of scrambler sequence by introducing subband index number ₂(), like this, just can generate different scrambler sequence to different sub-band.

In actual applications, said method is utilized to obtain first m sequence x ₁() and second m sequence x ₂after (), those skilled in the art can generate corresponding scrambler sequence according to existing method, do not repeat them here.

Particularly, following several method can be adopted to obtain second m sequence x ₂().

Method one: according to $c_{\mathrm{init}}=(2*\mathrm{SubBandIndex}+1)\×({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, SubBandIndex is subband index number, for Cell Identity CI.

Method two: according to $c_{\mathrm{init}}=(2\×\mathrm{SubBandIndex}+n_s+1)\×({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, SubBandIndex is subband index number, n _sfor configuring the subframe numbers of the channel place radio frames of described subband, for Cell Identity CI.

Method three: according to $c_{\mathrm{init}}=(2{\×n}_{\mathrm{RNTI}}+1)\×(2\×\mathrm{SubBandIndex}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, n _rNTIfor radio network temporary identifier, SubBandIndex is subband index number, for Cell Identity CI.

Method four: according to $c_{\mathrm{init}}=(2{\×n}_{\mathrm{RNTI}}+1)\×(2\×\mathrm{SubBandIndex}+n_s+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, n _rNTIfor radio network temporary identifier, SubBandIndex is subband index number, for Cell Identity CI, n _sfor configuring the subframe numbers of the channel place radio frames of described subband.

Preferably, when described subband be Physical Control Format Indicator Channel (PCFICH), subband shared by Physical HARQ Indicator Channel (PHICH) or Physical Downlink Control Channel (PDCCH) time, said method one or method two can be adopted to obtain second m sequence x ₂().

Preferably, when the subband of described subband shared by Physical Downlink Shared Channel (PDSCH), said method three or method four can be adopted to obtain second m sequence x ₂().

In sum, these are only preferred embodiment of the present invention, be not intended to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a collocation method for scramble initial value, the method is used in the discontinuous system of working frequency range, and it is characterized in that, the method comprises the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂();

Wherein, according to $c_{\mathrm{init}}=(2*\mathrm{SubBandIndex}+1)\×({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, SubBandIndex is subband index number, for Cell Identity CI.

2. method according to claim 1, is characterized in that, described subband is Physical Control Format Indicator Channel PCFICH, Physical HARQ Indicator Channel PHICH or the subband shared by physical downlink control channel PDCCH.

3. a collocation method for scramble initial value, the method is used in the discontinuous system of working frequency range, and it is characterized in that, the method comprises the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂();

Wherein, according to $c_{\mathrm{init}}=(2\×\mathrm{SubBandIndex}+n_s+1)\×({2N}_{\mathrm{ID}}^{\mathrm{cell}}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, SubBandIndex is subband index number, n _sfor configuring the subframe numbers of the channel place radio frames of described subband, for Cell Identity CI.

4. method according to claim 3, is characterized in that, described subband is Physical Control Format Indicator Channel PCFICH, Physical HARQ Indicator Channel PHICH or the subband shared by physical downlink control channel PDCCH.

5. a collocation method for scramble initial value, the method is used in the discontinuous system of working frequency range, and it is characterized in that, the method comprises the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂();

Wherein, according to $c_{\mathrm{init}}=(2\×n_{\mathrm{RNTI}}+1)\×(2\×\mathrm{SubBandIndex}+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, n _rNTIfor radio network temporary identifier, SubBandIndex is subband index number, for Cell Identity CI.

6. method according to claim 5, is characterized in that, the subband of described subband shared by Physical Downlink Shared Channel PDSCH.

7. a collocation method for scramble initial value, the method is used in the discontinuous system of working frequency range, and it is characterized in that, the method comprises the following steps:

When needs arrange scrambler initial value for subband, according to x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, initialization is for generating first m sequence x of scrambler sequence ₁(), according to subband index number and the Cell Identity CI of described subband, initialization is for generating second m sequence x of scrambler sequence ₂();

Wherein, according to $c_{\mathrm{init}}=(2\×n_{\mathrm{RNTI}}+1)\×(2\×\mathrm{SubBandIndex}+n_s+1)\×2^9+N_{\mathrm{ID}}^{\mathrm{cell}}$ Calculate c _init, utilize described c _init, according to initialization is for generating second m sequence x of scrambler sequence ₂(), wherein, n _rNTIfor radio network temporary identifier, SubBandIndex is subband index number, for Cell Identity CI, n _sfor configuring the subframe numbers of the channel place radio frames of described subband.

8. method according to claim 7, is characterized in that, the subband of described subband shared by Physical Downlink Shared Channel PDSCH.