CN105307260A - Method for sending synchronous signal sequence - Google Patents

Abstract

The invention discloses a method for sending a synchronous signal sequence. The method comprises the following steps: for each ordinary frequency point in a synchronous frame, generating a primary synchronous signal sequence and a secondary synchronous signal sequence occupying the ordinary frequency point according to an absolute frequency point index number and a cell identifier of the ordinary frequency point; mapping the primary synchronous signal sequence onto a primary synchronous time-frequency resource corresponding to the ordinary frequency point in the synchronous frame; mapping the secondary synchronous signal sequence onto a secondary synchronous time-frequency resource corresponding to the ordinary frequency point in the synchronous frame; and for each ordinary frequency point, generating a time domain continuous signal of the ordinary frequency point transmitted by corresponding OFDM symbols in the synchronous frame on a single antenna port by means of sequence symbols mapped onto the synchronous time-frequency resources, and carrying out corresponding transmission. The method disclosed by the invention can be used for effectively avoiding the problem of a high peak-to-average ratio due to superposition of synchronous signals, and is suitable for private network wireless communication systems with carrier aggregation characteristics.

Description

The sending method of synchronous signal sequence

Technical field

The present invention relates to mobile communication technology, particularly relate to a kind of sending method of synchronous signal sequence.

Background technology

TD-LTE system synchronously have employed two kinds of custom-designed physical signallings, each community is broadcasted, and they are master sync signal (PSS) and auxiliary synchronous signals (SSS) respectively.The detection of these two kinds of signals not only makes time and Frequency Synchronization, and provides UE physical-layer cell identifier and circulating prefix-length, notice UE Frequency Division Duplexing (FDD) that community uses (FDD) or time division duplex (TDD).

In TDD cell, no matter system bandwidth how, time domain and the frequency domain position of PSS and SSS are fixed, PSS is positioned on 72, the centre subcarrier of the 3rd OFDM (OFDM) symbol of time slot 2 and time slot 12, and SSS is positioned on 72, the centre subcarrier of last OFDM symbol of time slot 1 and time slot 11.

The ZC sequence that master sync signal is 63 by length forms, the centre element destroyed that is perforated is in order to avoid direct current carrier, this sequence is only relevant with sector ID, for the PSS sequence of 3 in LTE, the sector ID of corresponding each community, good autocorrelation and cross correlation can be met by 3 the ZCPSS sequences selected, there is the characteristic of low peak average ratio.

The BPSK that SSS sequence is 31 by two length on frequency domain modulates that auxiliary synchronous code is staggered to be formed, and this sequence is relevant with sector ID and cell set ID, and is used for the frame header position of a differentiation radio frames, has the characteristic of low peak average ratio.

For a community, because sector ID and cell set ID fix, therefore, the master sync signal of generation and auxiliary synchronous signals sequence are the sequences determined.

The synchronizing signal generating method of above-mentioned TD-LTE system, is only applicable to the wireless communication system with single-frequency point, and for having the private network wireless communication system of carrier aggregation feature, then inapplicable.Make a concrete analysis of as follows:

Fig. 1 is the spectrum diagram of such private network wireless communication system.As shown in Figure 1, have in the system of carrier aggregation feature and comprise multiple common frequency, namely each 25kHz is a frequency, for ensureing that UE carries out normal carrier synchronization and time synchronized on each common frequency, hold at eNodeB, each common frequency equals the radio frames (this frame is called synchronization frame) of 0 sends synchronizing signal simultaneously at radio frame number mould 40, take identical resource location, each frequency carries out separately IFFT and generates time-domain signal, then carry out the superposition of time domain after being modulated on corresponding carrier frequency, then sent by antenna port.If each frequency of such private network wireless communication system adopts the synchronizing signal generating method of TD-LTE, so before carrying out IFFT conversion, multiple frequency can generate identical frequency-region signal (f ₁, f ₂... f _n), so through IFFT, filter filtering after being modulated to respective carrier frequency, during the Signal averaging of multiple carrier frequency, if the phase place of multiple signal is consistent, the instantaneous power of the superposed signal obtained far away higher than the average power of signal, will can cause very high peak-to-average force ratio (PAPR) problem.

Summary of the invention

In view of this, main purpose of the present invention is the sending method providing a kind of synchronous signal sequence, and the method is applicable to be had in the private network wireless communication system of carrier aggregation feature.

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

A sending method for synchronous signal sequence, comprising:

For each common frequency in synchronization frame, according to absolute frequency call number and the cell ID of this common frequency, generate the master sync signal sequence and the auxiliary synchronous signals sequence that take this common frequency; By on the synchronous running time-frequency resource of master corresponding for this common frequency in described master sync signal sequence mapping to described synchronization frame; By on auxiliary synchronous running time-frequency resource corresponding for this common frequency in described auxiliary synchronous signals sequence mapping to described synchronization frame;

For each described common frequency, utilize the sequence symbol be mapped on described synchronous running time-frequency resource, generate the time domain continuous signal that this common frequency each OFDM symbol corresponding in described synchronization frame is launched on single antenna port, and launch accordingly.

In sum, the sending method of the synchronous signal sequence that the present invention proposes, according to absolute frequency call number and the cell ID of common frequency, generate the master sync signal sequence and the auxiliary synchronous signals sequence that take this common frequency, effectively can avoid the high peak-to-average power ratio problem caused by superposition of synchronizing signal, therefore, be applicable to have in the private network wireless communication system of carrier aggregation feature.

Accompanying drawing explanation

Fig. 1 is private network communication system spectrum schematic diagram;

Fig. 2 is the schematic flow sheet of the embodiment of the present invention one.

Embodiment

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

Core concept of the present invention is: when generating master sync signal sequence and the auxiliary synchronous signals sequence of each common frequency, consider absolute frequency call number, make the synchronous signal sequence of different common frequency not identical, with the high peak-to-average power ratio problem caused by the superposition avoiding identical synchronizing signal.

Fig. 2 is the schematic flow sheet of the embodiment of the present invention one, and as shown in Figure 2, the sending method of the synchronous signal sequence that this embodiment realizes mainly comprises:

Step 201, for each common frequency in synchronization frame, according to absolute frequency call number and the cell ID of this common frequency, generate and take master sync signal sequence and the auxiliary synchronous signals sequence of this common frequency; By on the synchronous running time-frequency resource of master corresponding for this common frequency in described master sync signal sequence mapping to described synchronization frame; By on auxiliary synchronous running time-frequency resource corresponding for this common frequency in described auxiliary synchronous signals sequence mapping to described synchronization frame.

In this step, introduce the absolute frequency call number of common frequency, so with the generation difference of existing synchronous signal sequence, the synchronizing signal of different common frequency can be made not identical, thus the high peak-to-average power ratio problem of generation when can avoid the synchronizing signal superposition of multiple frequency.

In actual applications, described master sync signal sequence and auxiliary synchronous signals sequence can adopt identical method to generate, because in the private network wireless communication system with carrier aggregation feature, master sync signal sequence and auxiliary synchronous signals sequence all take 7 OFDM symbol, each OFDM symbol occupies 10 sub-carrier resources, like this, master sync signal sequence and auxiliary synchronous signals sequence all need to be mapped in 70 time/frequency source block, therefore, need to generate the pseudo random sequence with 70 sampled points.

Particularly, the generation of described master sync signal sequence can realize by the following method:

Step x1, according to c (n)=(x ₁(n+N _c)+x ₂(n+N _c)) mod2 generation random sequence c (n) (n=0,1 ..., 69).

Wherein, x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, x ₁(n+31)=(x ₁(n+3)+x ₁(n)) mod2; ${\mathrm{\Σ}}_{i=0}^{30}{x}_2\left(i\right)\·2^i=2866\·(2*\mathrm{SubBandIndex}+1)\·2^9+N_{\mathrm{ID}}^{\mathrm{cell}},$ SubBandIndex is the absolute frequency call number of common frequency, for cell ID, x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n)) mod2; N _c=1600.

Step x2, utilize described random sequence c (n), according to $r_{\mathrm{ss}1}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1))$ Obtain described synchronous signal sequence r _ss1(m) (m=0,1 ..., 69).

Particularly, the generation of described auxiliary synchronous signals sequence can realize by the following method:

Step y1, according to c (n)=(x ₁(n+N _c)+x ₂(n+N _c)) mod2 generation random sequence c (n) (n=0,1 ..., 69),

Wherein, x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, x ₁(n+31)=(x ₁(n+3)+x ₁(n)) mod2; ${\mathrm{\Σ}}_{i=0}^{30}{x}_2\left(i\right)\·2^i=2866\·(2*\mathrm{SubBandIndex}+1)\·2^9+N_{\mathrm{ID}}^{\mathrm{cell}},$ SubBandIndex is the absolute frequency call number of common frequency, for cell ID, x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n)) mod2; N _c=1600.

Step y2, utilize described random sequence c (n), according to $r_{\mathrm{ss}2}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\·c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\·c(2m+1))$ Obtain described synchronous signal sequence r _ss2(m) (m=0,1 ..., 69).

Preferably, when realizing the mapping between synchronizing signal and running time-frequency resource, the mode of first frequency domain k time domain l again can be adopted to carry out, namely, the synchronizing signal be made up of 70 sampled points (master sync signal or auxiliary synchronous signals) is divided into 7 sections, the length of every section is 10 points, is mapped to by the sequence symbol of same section in identical OFDM symbol, specific as follows:

According to by described master sync signal sequence r _ss1m () is mapped on the synchronous running time-frequency resource of master that in described synchronization frame, this common frequency is corresponding, wherein, be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding.

According to by described auxiliary synchronous signals sequence r _ss2m () is mapped on the auxiliary synchronous running time-frequency resource that in described synchronization frame, this common frequency is corresponding, wherein, be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding.

Here it should be noted that, in the private network wireless communication system of existing discontinuous spectrum bandwidth, auxiliary synchronous running time-frequency resource in synchronization frame is after main isochronous resources, namely front 7 OFDM symbol are for carrying auxiliary synchronous signals, rear 7 OFDM symbol for carrying master sync signal, therefore, in above-mentioned mapping process, for master sync signal and for auxiliary synchronous signals, then

Said method have employed the mode of first frequency domain k time domain l again, is not limited to this in actual applications, also can adopt the mode of first time domain frequency domain again, not repeat them here.

Step 202, for each described common frequency, utilize the sequence symbol be mapped on described synchronous running time-frequency resource, generate the time domain continuous signal that this common frequency each OFDM symbol corresponding in described synchronization frame is launched on single antenna port, and launch accordingly.

In this step, in the generation of time domain continuous signal, the circulating prefix-length of OFDM symbol is different, and in order to distinguish primary and secondary synchronization signals, the mutual interference of both minimizings, will be according to arrange.

Preferably, following method can be adopted in this step to generate described time domain continuous signal:

When n _{cp, l}× T _s≤ t < (N _{cp, l}+ N) × T _stime, according to generate descending n-th _rBthe time domain continuous signal that on the synchronization frame of individual common frequency, l OFDM symbol is launched on single antenna port wherein, l is the numbering of OFDM symbol, Δ f=2kHz, N=64, t _sfor the sampling interval, f _sfor baseband sampling rate, f _s=128kHz; be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding; be the total number of sub-carriers that a common frequency comprises, for the OFDM symbol sum that synchronizing signal takies; n _{cP, l}it is the circulating prefix-length of l OFDM symbol; t is delivery time.

Work as l=0,0≤t < N _{cp, 0}× T _stime, according to generate described time domain continuous signal

Work as l=7,0≤t < N _{cp, 7}× T _stime, according to generate described time domain continuous signal

In this step, the transmitting of time domain continuous signal with existing LTE system, that is, n-th _rBin synchronization frame on individual frequency, OFDM symbol should according to the sequential transmission that l increases progressively from l=0, and in subframe, the OFDM symbol of l > 0 is in the moment ${\mathrm{\&Sigma;}}_{l^{\&prime;}=0}^{l-1}(N_{\mathrm{CP},l^{\&prime;}}+N)T_s$ Start to launch.

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 (6)

1. a sending method for synchronous signal sequence, is characterized in that, comprising:

For each common frequency in synchronization frame, according to absolute frequency call number and the cell ID of this common frequency, generate the master sync signal sequence and the auxiliary synchronous signals sequence that take this common frequency; By on the synchronous running time-frequency resource of master corresponding for this common frequency in described master sync signal sequence mapping to described synchronization frame; By on auxiliary synchronous running time-frequency resource corresponding for this common frequency in described auxiliary synchronous signals sequence mapping to described synchronization frame;

For each described common frequency, utilize the sequence symbol be mapped on described synchronous running time-frequency resource, generate the time domain continuous signal that this common frequency each OFDM symbol corresponding in described synchronization frame is launched on single antenna port, and launch accordingly.

2. method according to claim 1, is characterized in that, the generation of described master sync signal sequence comprises:

According to c (n)=(x ₁(n+N _c)+x ₂(n+N _c)) mod2 generation random sequence c (n) (n=0,1 ..., 69),

Wherein, x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, x ₁(n+31)=(x ₁(n+3)+x ₁(n)) mod2; ${\mathrm{\&Sigma;}}_{i=0}^{30}{x}_2\left(i\right)\&CenterDot;2^i=2866\&CenterDot;(2*\mathrm{SubBandIndex}+1)\&CenterDot;2^9+N_{\mathrm{ID}}^{\mathrm{cell}},$ SubBandIndex is the absolute frequency call number of common frequency, for cell ID, x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n)) mod2; N _c=1600;

Utilize described random sequence c (n), according to $r_{\mathrm{ss}1}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\&CenterDot;c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\&CenterDot;c(2m+1))$ Obtain described synchronous signal sequence r _ss1(m) (m=0,1 ..., 69).

3. method according to claim 1, is characterized in that, the generation of described auxiliary synchronous signals sequence comprises:

According to c (n)=(x ₁(n+N _c)+x ₂(n+N _c)) mod2 generation random sequence c (n) (n=0,1 ..., 69),

Wherein, x ₁(0)=1, x ₁(n)=0, n=1,2 ..., 30, x ₁(n+31)=(x ₁(n+3)+x ₁(n)) mod2; ${\mathrm{\&Sigma;}}_{i=0}^{30}{x}_2\left(i\right)\&CenterDot;2^i=2866\&CenterDot;(2*\mathrm{SubBandIndex}+1)\&CenterDot;2^9+N_{\mathrm{ID}}^{\mathrm{cell}},$ SubBandIndex is the absolute frequency call number of common frequency, for cell ID, x ₂(n+31)=(x ₂(n+3)+x ₂(n+2)+x ₂(n+1)+x ₂(n)) mod2; N _c=1600;

Utilize described random sequence c (n), according to $r_{\mathrm{ss}2}\left(m\right)=\frac{1}{\sqrt{2}}(1-2\&CenterDot;c\left(2m\right))+j\frac{1}{\sqrt{2}}(1-2\&CenterDot;c(2m+1))$ Obtain described synchronous signal sequence r _ss2(m) (m=0,1 ..., 69).

4. method according to claim 2, is characterized in that, according to by described master sync signal sequence r _ss1m () is mapped on the synchronous running time-frequency resource of master that in described synchronization frame, this common frequency is corresponding, wherein, be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding.

5. method according to claim 3, is characterized in that, according to by described auxiliary synchronous signals sequence r _ss2m () is mapped on the auxiliary synchronous running time-frequency resource that in described synchronization frame, this common frequency is corresponding, wherein, be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding.

6. method according to claim 1, is characterized in that, the generation of described time domain continuous signal comprises:

When n _{cp, l}× T _s≤ t < (N _{cp, l}+ N) × T _stime, according to generate descending n-th _rBthe time domain continuous signal that on the synchronization frame of individual common frequency, l OFDM symbol is launched on single antenna port wherein, l is the numbering of OFDM symbol, Δ f=2kHz, N=64, t _sfor the sampling interval, f _sfor baseband sampling rate, f _s=128kHz; be n-th _rBthe time/frequency source block indicated by a l OFDM symbol kth subcarrier that individual common frequency is corresponding; be the total number of sub-carriers that a common frequency comprises, for the OFDM symbol sum that synchronizing signal takies; n _{cP, l}it is the circulating prefix-length of l OFDM symbol; t is delivery time;

Work as l=0,0≤t < N _{cp, 0}× T _stime, according to generate described time domain continuous signal

Work as l=7,0≤t < N _{cp, 7}× T _stime, according to generate described time domain continuous signal