CN103795515A - Method for sending downlink pilot frequency in private-network communication system - Google Patents

Abstract

The application discloses a method for sending a downlink pilot frequency in a private-network communication system. The method includes: A. setting specific subcarriers in each wireless frame in each sub-band as a pilot-frequency resource group; B. for any a cell, taking the modulus of 4 on a cell identification and determining an OFDM symbol, which the cell pilot frequency is in, in the pilot-frequency resource group according to the modulus taking result. Through application of the application scheme, the pilot frequency of a cell can be free from interferences from services of an adjacent cell or the pilot frequency of the adjacent cell.

Description

In a kind of private network communication system, send the method for descending pilot frequency

Technical field

The application relates to mobile communication technology field, relates in particular to a kind of method that sends descending pilot frequency in private network communication system.

Background technology

Private network communication system takies discontinuous spectral bandwidth, and its schematic diagram as shown in Figure 1.Each 25kHz is a subband.There are at most 480 subbands.A wireless frame length of the each subband of private network system is 25ms, comprises 45 OFDM symbols.As shown in Figure 2, downlink resource takies 13 OFDM symbols, and random access resource comprises 4 OFDM symbols, and ascending resource comprises 27 OFDM symbols.

As shown in Figure 3, grey mark represents pilot tone position to descending pilot frequency pattern in subband of private network communication system.On each OFDM symbol, there is a Resource Unit (RE, Resource Element) as pilot tone, the position of this pilot tone (k, l, n _pRB) according to cell ID definitely subband index n _pRB, OFDM symbol l determines, specific as follows:

$k=(v_{\mathrm{shift}}+l)\mathrm{mod}{N}_{\mathrm{sc}}^{\mathrm{RB}}$

l＝0,1,...,12

$n_{\mathrm{PRB}}=\mathrm{0,1},...,N_{\mathrm{RB}}^{\mathrm{DL}}$

Wherein $v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}{N}_{\mathrm{SC}}^{\mathrm{RB}},$ $N_{\mathrm{sc}}^{\mathrm{RB}}=10,$ $N_{\mathrm{ID}}^{\mathrm{cell}}=\mathrm{0,1},...,503.$

bandwidth by system determines.

In the time there is co-channel interference in private network communication system, send pilot tone according to the descending pilot frequency pattern shown in Fig. 3, the pilot tone of the business Dui Zhe community of adjacent cell has interference.Affect the accuracy of channel estimating and channel measurement, and then affect the demodulation performance of system.For this reason, need to redesign pilot tone, to improve its jamproof ability.

Summary of the invention

The application provides a kind of method that sends descending pilot frequency in private network communication system, and pilot tone that can Shi Ben community is not subject to the interference of adjacent area business or adjacent area pilot tone.

The method that sends descending pilot frequency in a kind of private network communication system that the embodiment of the present application provides, comprising:

A, specific subcarrier is set in each subband in each radio frames as pilot resources group;

B, for any community, cell ID, to 4 deliverys, is determined to the OFDM symbol at this district pilots place in pilot resources group according to delivery result.

Preferably, be 2 as the number of the subcarrier of pilot resources group, as all or part of OFDM symbol in the descending time slot of the subcarrier of pilot resources group as pilot tone.

Preferably, pilot resources group is fixed as front 12 OFDM symbols of the 3rd and the 8th subcarrier of the each subband of each radio frames.

As can be seen from the above technical solutions, for each subband arranges proprietary pilot resources group, in proprietary pilot resources group, distinguish the pilot tone of different districts by the mode of time-division, thereby pilot tone that can Shi Ben community is not subject to the interference of adjacent area business or adjacent area pilot tone, reaches the object of anti-co-channel interference.

Accompanying drawing explanation

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

Fig. 2 is subband time interval resource structural representation;

Fig. 3 is private network descending pilot frequency pattern of the prior art;

In a kind of private network communication system that Fig. 4 provides for the embodiment of the present application, send the method flow schematic diagram of descending pilot frequency;

The descending pilot frequency pattern schematic diagram of the private network communication system that Fig. 5 provides for the embodiment of the present application.

Embodiment

The present invention, by private network communication system, for each subband arranges proprietary pilot resources group, in proprietary pilot resources group, distinguishes the pilot tone of different districts, to reach the object of anti-co-channel interference by the mode of time-division.

For making know-why, feature and the technique effect of present techniques scheme clearer, below in conjunction with specific embodiment, present techniques scheme is described in detail.

In a kind of private network communication system that the embodiment of the present application provides, send the method flow of descending pilot frequency as shown in Figure 4, comprising:

Step 401: specific subcarrier is set in each subband in each radio frames as pilot resources group.

Preferably, be 2 as the number of the subcarrier of pilot resources group, as all or part of OFDM symbol in the descending time slot of the subcarrier of pilot resources group as pilot tone.

In the embodiment of the present application, pilot resources group is fixed as front 12 OFDM symbols of the 3rd and the 8th subcarrier of the each subband of each radio frames.

Step 402: cell ID, to 4 deliverys, is determined to the OFDM symbol at this district pilots place in pilot resources group according to delivery result.The resource location that does not send pilot tone in pilot resources group does not send any signal.

Preferably, determine position (k, l, the n of pilot tone according to following formula _pRB):

k＝2，7

l＝v _shift,v _shift+4,v _shift+8

n _PRB＝0,1,...,479

Wherein $v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}4,$

Wherein,

for cell ID, n _pRBfor absolute subband index.

Figure 5 shows that the descending pilot frequency pattern of the private network communication system that the embodiment of the present application provides.Wherein, the position of flakes shadow representation pilot resources group, the pilot tone position of one of them community of latticed shadow representation.

By application the application scheme, pilot tone that can Shi Ben community is not subject to the interference of adjacent area business or adjacent area pilot tone, reaches the object of anti-co-channel interference.

The foregoing is only the application's preferred embodiment; not in order to limit the application's protection range; all within the spirit and principle of present techniques scheme, any modification of making, be equal to replacement, improvement etc., within all should being included in the scope of the application's protection.

Claims (3)

1. a method that sends descending pilot frequency in private network communication system, is characterized in that, comprising:

A, specific subcarrier is set in each subband in each radio frames as pilot resources group;

B, for any community, cell ID, to 4 deliverys, is determined to the OFDM symbol at this district pilots place in pilot resources group according to delivery result.

2. method according to claim 1, is characterized in that, is 2 as the number of the subcarrier of pilot resources group, as all or part of OFDM symbol in the descending time slot of the subcarrier of pilot resources group as pilot tone.

3. method according to claim 2, is characterized in that, pilot resources group is fixed as front 12 OFDM symbols of the 3rd and the 8th subcarrier of the each subband of each radio frames.

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