CN101309228B - Frequency domain initial position setting method of physical stochastic access channel - Google Patents

Abstract

The invention provides a setting method of the frequency domain initial position of the physical random accessing channel, which includes that at least one of the conditions is judged, including the total RB number which is corresponding to the configured upstream system bandwidth, the preamble format of the PRACH and the maximum SRS bandwidth; the frequency domain initial position of the PRACH is set according to the judgment result. Because the frequency domain initial position of the PRACH is reasonably set through the setting method according to the total RB number which is corresponding to the configured upstream system bandwidth, the preamble format of the PRACH and the maximum SRS bandwidth, the disturbance of the PRACH with the PUCCH and the SRS is avoided; meanwhile, the PUSCH is avoided from being divided into multiple segments so that the scheduling flexibility is improved.

Description

The method to set up of Physical Random Access Channel frequency domain initial position

Technical field

The present invention relates to the communications field, in particular to a kind of method to set up of Physical Random Access Channel frequency domain initial position.

Background technology

The frame structure (be called again the Equations of The Second Kind frame structure, namely framestructure type 2) of LTE (Long Term Evolution, Long Term Evolution) system TDD (Time DivisionDuplex, time division duplex) pattern as shown in Figure 1.In this frame structure, the radio frames of a 10ms (307200Ts, 1ms=30720Ts) is divided into two fields, each half frame length 5ms (153600Ts).The subframe that it is 1ms that each field comprises 5 length.The effect of each subframe is as shown in table 1, and wherein D (Downlink) representative is used for the descending sub frame of transmission of downlink signal.U (Uplink) representative is used for the sub-frame of uplink of transmission upward signal.In addition, upstream or downstream subframe is divided into again the time slot of 2 0.5ms.S (Special) represents special subframe; comprise three special time slots, i.e. DwPTS (Downlink Pilot Time Slot, descending pilot frequency time slot), GP (Guard Period; protect the interval) and UpPTS (UplinkPilot Time Slot, uplink pilot time slot).In real system, the uplink and downlink formulatory indices can be notified to mobile phone by broadcast.

The preparation of table 1 uplink and downlink

The frame structure (being called again first kind frame structure, i.e. frame structure type 1) of the FDD of LTE system (Frequency Division Duplex, Frequency Division Duplexing (FDD)) pattern as shown in Figure 2.The radio frames of a 10ms is divided into the time slot of 20 0.5ms, and adjacent 2 time slots form the subframe that length is 1ms, and namely subframe i is comprised of time slot 2i and 2i+1, i=0 wherein, and 1 ..., 9.Under fdd mode, 10 subframes all are used for the transmission of upstream or downstream signal, distinguish by different frequency bands between the uplink and downlink.

The structure of LTE system physical accidental access channel (PRACH, Physical Random AccessChannel, or be called random access chance, i.e. random access opportunity) as shown in Figure 3.Preamble (leading) is comprised of CP and Sequence two parts, and different preamble format (leading form) means different CP and/or Sequence length.The preamble format kind of at present LTE system TDD mode support is as shown in table 2.

The leading form of table 2

Preamble format	T CP	T SEQ
			0	3168·T s	24576·T s
1	21024·T s	24576·T s
			2	6240·T s	2·24576·T s
3	21024·T s	2·24576·T s
			4(frame structure type 2 only)	448·T s	4096·T s

In the above-mentioned leading form, preamble format 0～3 transmits in common sub-frame of uplink, and preamble format 4 transmits in UpPTS.

Preamble format 0 transmits in a common sub-frame of uplink;

Preamble format 1,2 transmits in two common sub-frame of uplink;

Preamble format 3 transmits in three common sub-frame of uplink;

Preamble format 4 transmits (original position sends the 5158Ts position in advance at the place, end of UpPTS) in UpPTS

At frequency domain, a PRACH accounts for 6 Resource Block (RB, Resource Block), and each RB comprises 12 subcarriers, and the bandwidth of each subcarrier is 15kHz.The PRACH that time-domain position is identical distinguishes by frequency domain.

On frequency domain, common sub-frame of uplink can transmit PRACH, Physical Shared Channel (PUSCH, Physical uplink shared channel), Physical Uplink Control Channel (PUCCH, Physical uplink control channel), the physical channel/signal such as detection reference signal (SRS, Sounding reference signal).UpPTS bag can the transmitting SRS signal and leading form be 4 PRACH.In common sub-frame of uplink, the structure of PUCCH and SRS signal as shown in Figure 4.The bandwidth of SRS signal adopts tree to prepare, the corresponding tree of each SRS bandwidth preparation (being SRS bandwidth configuration), the maximum bandwidth of this SRS bandwidth preparation that top SRS bandwidth (SRS-Bandwidth) is corresponding.Total RB number corresponding to definition upstream bandwidth preparation is N _RB ^UL, table 3 has provided as 6≤N _RB ^ULThe example of SRS bandwidth preparation in≤40 o'clock, wherein the b=0 correspondence the maximum bandwidth of various SRS bandwidth preparations.

Table 3

The frequency domain initial position of PRACH refers in all PRACH, the position of first RB that the PRACH of frequency domain position minimum (being that the RB index is minimum) is shared.The frequency domain position of other PRACH is all based on this position calculation out: for leading form 0～3, calculate the frequency domain position of the identical PRACH of time-domain position by formula (1).

Wherein, n _PRBRAoffset ^RAFrequency domain initial position for PRACH; N _RB ^ULBe total RB number corresponding to up-link bandwidth preparation; f _RAFrequency domain index for the identical PRACH of time-domain position.For leading format 4, calculate the frequency domain position of the identical PRACH of time-domain position by formula (2)

$n_{\mathrm{PRB}}^{\mathrm{RA}}=\left\{\begin{array}{cc}{n}_{\mathrm{PRBoffset}}^{\mathrm{RA}}+{6f}_{\mathrm{RA}},& \mathrm{if}(\left(n_f\mathrm{mod}2\right)\&times;(2-N_{\mathrm{SP}})+t_{\mathrm{RA}}^1)\mathrm{<figure-callout\; id="2"\; label="mod"\; filenames="S2008101376416E00012.png,S2008101376416E00021.png"\; state="\{\{state\}\}">mod</figure-callout>}2=0\\ N_{\mathrm{RB}}^{\mathrm{UL}}-6-n_{\mathrm{PRBoffset}}^{\mathrm{RA}}-{6f}_{\mathrm{RA}},& \mathrm{otherwise}\end{array}\right.$

Wherein, n _fBe radio frames numbering, N _SPIt is the number of a 10ms radio frames downstream-to-upstream transfer point.

The initial position of PRACH frequency domain has directly determined the distribution of other PRACH on the frequency domain, therefore will affect the frequency domain multiplexing relation of PRACH and PUCCH and SRS.In the prior art, rational solution is proposed arranging of PRACH frequency domain initial position, and if optionally arrange and cause arranging unreasonable, then will produce interferences to PUCCH, and also PUSCH might be divided into multistage, the complexity that increase is dispatched.

Summary of the invention

The present invention aims to provide a kind of method to set up of Physical Random Access Channel PRACH frequency domain initial position, to solve the interference problem of PRACH and PUCCH and SRS.

According to an aspect of the present invention, a kind of method to set up of Physical Random Access Channel frequency domain initial position is provided, may further comprise the steps: judge following at least one condition: the up-link bandwidth is prepared the leading form of corresponding total RB number, PRACH, maximum SRS bandwidth, and the frequency domain initial position of PRACH is set according to judged result.The frequency domain initial position of PRACH refers in all PRACH, the position of first RB that the PRACH of frequency domain position minimum (being that the RB index is minimum) is shared.

Preferably, judgement up-link bandwidth is prepared corresponding total RB and is counted N _RB ^ULBe not more than predetermined threshold or less than predetermined threshold, the frequency domain initial position that then according to judged result PRACH is set specifically comprises: the frequency domain initial position that PRACH is set is 0; Or the frequency domain initial position that PRACH is set is

Or

Preferably, predetermined threshold is 10.

Preferably, judge that the leading form of PRACH is 4, the frequency domain initial position that then according to judged result PRACH is set specifically comprises: the frequency domain initial position that PRACH is set is 0.

Preferably, judgement up-link bandwidth is prepared corresponding total RB and is counted N _RB ^ULBe not less than predetermined threshold or greater than predetermined threshold, maximum SRS bandwidth equals 4, and the leading form of PRACH is not 4, the frequency domain initial position that then according to judged result PRACH is set specifically comprises: the frequency domain initial position that PRACH is set is 0; Or the frequency domain initial position that PRACH is set is Or

Preferably, predetermined threshold is 10.

Preferably, judge that the corresponding total RB of up-link bandwidth counts N _RB ^ULBe not less than predetermined threshold or greater than predetermined threshold, maximum SRS band is wider than 4, and the leading form of PRACH is not 4, and the frequency domain initial position that then according to judged result PRACH is set specifically comprises: the frequency domain initial position that PRACH is set is

Or

M wherein _{SRS, 0}Be maximum SRS bandwidth in the preparation of SRS bandwidth.

Preferably, predetermined threshold is 10.

The method to set up of the PRACH frequency domain initial position of above-described embodiment is because prepare the frequency domain initial position that corresponding total RB number, the leading form of PRACH, maximum SRS bandwidth reasonably are provided with PRACH according to the up-link bandwidth, so avoided the interference of PRACH and PUCCH and SRS, simultaneously can also avoid PUSCH is divided into multistage as far as possible, improve the flexibility of scheduling.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, and illustrative examples of the present invention and explanation thereof are used for explaining the present invention, do not consist of improper restriction of the present invention.In the accompanying drawings:

Fig. 1 shows the frame structure of LTE system TDD mode;

Fig. 2 shows the frame structure of LTE system fdd mode;

Fig. 3 shows the PRACH structure;

Fig. 4 shows the structure of PUCCH and SRS;

Fig. 5 shows the flow chart according to the PRACH frequency domain initial position method to set up of the embodiment of the invention.

Embodiment

Below with reference to the accompanying drawings and in conjunction with the embodiments, describe the present invention in detail.

Fig. 5 shows the flow chart according to the PRACH frequency domain initial position method to set up of the embodiment of the invention, may further comprise the steps:

Step S10, judge following at least one condition: the up-link bandwidth is prepared the leading form of corresponding total RB number, PRACH, maximum SRS bandwidth;

Step S20 arranges the frequency domain initial position of PRACH according to judged result.The frequency domain initial position of PRACH refers in all PRACH, the position of first RB that the PRACH of frequency domain position minimum (being that the RB index is minimum) is shared.

This setting is because prepare the frequency domain initial position that corresponding total RB number, the leading form of PRACH, maximum SRS bandwidth reasonably are provided with PRACH according to the up-link bandwidth, so avoided the interference of PRACH and PUCCH and SRS, simultaneously can also avoid PUSCH is divided into multistage as far as possible, improve the flexibility of scheduling.

Preferably, judge that the up-link bandwidth prepares that corresponding total RB number is not more than predetermined threshold or less than predetermined threshold (for example 10), then

The frequency domain initial position that ■ arranges PRACH is 0; Or

The frequency domain initial position that ■ arranges PRACH is

Or

Preferably, be 4 PRACH for leading form, it is 0 that frequency domain initial position is set;

Preferably, judge that the corresponding total RB number of up-link bandwidth is not less than predetermined threshold or greater than predetermined threshold (for example 10), maximum SRS bandwidth equals 4, and the leading form of PRACH is not 4, then

The frequency domain initial position that ■ arranges PRACH is 0; Or

The frequency domain initial position that ■ arranges PRACH is

Or

Preferably, judge that the corresponding total RB number of up-link bandwidth is not less than predetermined threshold or greater than predetermined threshold (for example 10), maximum SRS band is wider than 4, and the leading form of PRACH is not 4, then determines that according to the maximum bandwidth of SRS signal the frequency domain initial position of PRACH is

Or M wherein _{SRS, 0}Be maximum SRS bandwidth in certain SRS bandwidth preparation.

Preferably, above-mentioned predetermined threshold can get 10.

Below in conjunction with embodiment, describe the present invention in detail.Suppose that predetermined threshold is 10

Implement one

The leading form of PRACH is preamble format 0, and total RB number corresponding to up-link bandwidth is 8.Then according to top method, the frequency domain initial value that PRACH is set is 0, namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=0.$

Implement two

The leading form of PRACH is preamble format 0, and total RB number corresponding to up-link bandwidth is 8.Then according to top method, the frequency domain initial value that PRACH is set is

Namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=1.$

Implement three

The leading form of PRACH is preamble format 4, and then according to top method, the frequency domain initial value that PRACH is set is 0, namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=0.$

Implement four

The leading form of PRACH is preamble format 0, and total RB number corresponding to up-link bandwidth is 50.The maximum SRS bandwidth m of system's preparation _{SRS, 0}=40, then according to top method, the frequency domain initial value that PRACH is set is

Namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=5.$

Implement five

The leading form of PRACH is preamble format 0, and total RB number corresponding to up-link bandwidth is 16.The maximum SRS bandwidth m of system's preparation _{SRS, 0}=4, then according to top method, the frequency domain initial value that PRACH is set is 0, namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=0.$

Implement six

The leading form of PRACH is preamble format 0, and total RB number corresponding to up-link bandwidth is 16.The maximum SRS bandwidth m of system's preparation _{SRS, 0}=4, then according to top method, the frequency domain initial value of PRACH is

Namely $n_{\mathrm{PRBoffset}}^{\mathrm{RA}}=5.$

As can be seen from the above description, said method of the present invention can be avoided the interference of PRACH and PUCCH and SRS, can also avoid PUSCH is divided into multistage simultaneously as far as possible, improves the flexibility of scheduling.

Obviously, those skilled in the art should be understood that, above-mentioned each module of the present invention or each step can realize with general calculation element, they can concentrate on the single calculation element, perhaps be distributed on the network that a plurality of calculation elements form, alternatively, they can be realized with the executable program code of calculation element, thereby, they can be stored in the storage device and be carried out by calculation element, perhaps they are made into respectively each integrated circuit modules, perhaps a plurality of modules in them or step are made into the single integrated circuit module and realize.Like this, the present invention is not restricted to any specific hardware and software combination.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (2)

1. the method to set up of a Physical Random Access Channel PRACH frequency domain initial position is characterized in that,

Judge following at least one condition: the up-link bandwidth is prepared leading form, the maximum probe reference signal SRS bandwidth of corresponding total resources piece RB number, PRACH;

The frequency domain initial position that PRACH is set according to judged result comprises that following judgement up-link bandwidth prepares corresponding total RB number Be not more than predetermined threshold or less than described predetermined threshold, the frequency domain initial position that then according to judged result PRACH is set comprises: the frequency domain initial position that PRACH is set is 0; Or the frequency domain initial position that PRACH is set is

Or

The leading form of judging PRACH is 4, and the frequency domain initial position that then according to judged result PRACH is set comprises: the frequency domain initial position that PRACH is set is 0;

Judgement up-link bandwidth is prepared corresponding total RB number

Be not less than predetermined threshold or greater than described predetermined threshold, maximum SRS bandwidth equals 4, and the leading form of PRACH is not 4, the frequency domain initial position that then according to judged result PRACH is set comprises: the frequency domain initial position that PRACH is set is 0; Or the frequency domain initial position that PRACH is set is

Or

Judge the corresponding total RB number of up-link bandwidth

Be not less than predetermined threshold or greater than described predetermined threshold, maximum SRS band is wider than 4, and the leading form of PRACH is not 4, and the frequency domain initial position that then according to judged result PRACH is set comprises: the frequency domain initial position that PRACH is set is

Or

M wherein _{SRS, 0}Be maximum SRS bandwidth in the preparation of SRS bandwidth.

2. method to set up according to claim 1 is characterized in that, described predetermined threshold is 10.

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