CN103796215A - Method for sending downlink pilot frequency in special network communication system - Google Patents

Abstract

The invention discloses a method for sending a downlink pilot frequency in a special network communication system. The method comprises: A, arranging a specific OFDM symbol in each sub-band as a pilot frequency resource group; B, for each OFDM symbol bearing a pilot frequency in the pilot frequency resource group, generating a piece of pilot frequency symbol data; and C, according to the generated piece of pilot frequency symbol data, generating eight pieces of pilot frequency symbol data through an eightfold spread spectrum mode, and performing mapping on eight resources units of an OFDM symbol bearing a pilot frequency, the pilot frequencies of different districts employing different spreading codes. By applying the scheme provided by the invention, the pilot frequency of a local district can be protected from the interference of neighboring district services or neighboring district pilot frequencies.

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 OFDM symbol is set in each subband as pilot resources group;

B, for the OFDM symbol of each carrying pilot tone in pilot resources group, produce a pilot symbol data;

C, generate 8 pilot symbol data according to a produced pilot symbol data by the mode of 8 times of spread spectrums, be mapped on 8 Resource Units of OFDM symbol of this carrying pilot tone; Wherein, the pilot tone of different districts adopts different spreading codes.

Preferably, be 3 as the number of the OFDM symbol of pilot resources group, and adjacent equating as the spacing between the OFDM symbol of pilot resources group.

Preferably, pilot resources group is fixed as 8 middle Resource Units of the 3rd, 7,11 OFDM symbols of each radio frames.

As can be seen from the above technical solutions, for each subband arranges proprietary pilot resources group, the mode of dividing by code in proprietary pilot resources group is distinguished the pilot tone of different districts, 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 passes through in private network communication system, for each subband arranges proprietary pilot resources group, and in proprietary pilot resources group, the mode of dividing by code, the pilot tone of differentiation different districts, to reach the object of anti-co-channel interference.

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: the interior specific OFDM symbol of each subband is set as pilot resources group.Preferably, be 3 as the number of the OFDM symbol of pilot resources group, and adjacent equating as the spacing between the OFDM symbol of pilot resources group.In the OFDM symbol of pilot resources group, all or part of Resource Unit is as pilot tone.

In the embodiment of the present application, pilot resources group is fixed as 8 Resource Units in the middle of the 3rd, 7,11 OFDM symbols of each radio frames.The descending pilot frequency pattern that Figure 5 shows that the private network communication system that the embodiment of the present application provides, wherein dash area has marked pilot tone position.

Position (k, l, the n of pilot tone _pRB) according to absolute subband index n _pRBdetermine.

k＝1,2,...,8

l＝2,6,10

n _PRB＝0,1,...,479

In actual applications, the position of pilot resources group also can be fixed on other OFDM symbols, and the application's scheme does not limit this.

Step 402: for the OFDM symbol of each carrying pilot tone in pilot resources group, produce a pilot symbol data.

Step 403: generate 8 pilot symbol data according to a produced pilot symbol data by the mode of 8 times of spread spectrums, be mapped on 8 Resource Units of OFDM symbol of this carrying pilot tone; Wherein, the pilot tone of different districts adopts different spreading codes.

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 OFDM symbol is set in each subband as pilot resources group;

B, for the OFDM symbol of each carrying pilot tone in pilot resources group, produce a pilot symbol data;

C, generate 8 pilot symbol data according to a produced pilot symbol data by the mode of 8 times of spread spectrums, be mapped on 8 Resource Units of OFDM symbol of this carrying pilot tone; Wherein, the pilot tone of different districts adopts different spreading codes.

2. method according to claim 1, is characterized in that, is 3 as the number of the OFDM symbol of pilot resources group, and adjacent equating as the spacing between the OFDM symbol of pilot resources group.

3. method according to claim 2, is characterized in that, pilot resources group is fixed as 8 Resource Units in the middle of the 3rd, 7,11 OFDM symbols of each radio frames.

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