CN101222248B

CN101222248B - Disturbance control method based on OSI bit

Info

Publication number: CN101222248B
Application number: CN200710000318XA
Authority: CN
Inventors: 方源立
Original assignee: ZTE Corp
Current assignee: State Grid Corp of China SGCC; State Grid Beijing Electric Power Co Ltd
Priority date: 2007-01-08
Filing date: 2007-01-08
Publication date: 2011-10-26
Anticipated expiration: 2027-01-08
Also published as: CN101222248A

Abstract

The invention discloses an interference control method based on OSI bit, comprising the following steps: the OSI bit and filter parameters of a subzone are received through a port; a terminal completes soft demodulation of the OSI bit information of an originating terminal; according to the received filter parameters, filtering processing of the soft OSI bit is completed by a filter; finally, power steplength is adjusted according to the output value of the filter. The method can effectively control the interference on other subzones caused by AT, and can inhibit the intense fluctuation of the OSI bit, thereby realizing smooth interference control and reduces the interference on other subzones; meanwhile, the method can furthest improve the stability and interference control performance of a system on the premise of safety and reliability; moreover, the method also increases the capacity of the system.

Description

Interference control method based on the OSI bit

Technical field

The present invention relates to a kind of interference control method of wireless communication system, relate in particular to the reverse interference control method in OFDM (OFDMA, the Orthogonal Frequency Division Multiple Access) communication system.

Background technology

Broadband wireless access technologys such as Wimax have formed challenge to cellular mobile communication technology, have accelerated the more evolved Study on Technology of 3G (Third Generation) Moblie and the standardized process of high transfer rate.3GPP of International Standards Organization and 3GPP2 have all started evolved Study on Technology of a 3G new round and standardization effort.Aloft interface layer two reaches the formulation of more high-rise standard to 3GPP2 wave point evolution (AIE-Air interference Evolution) project, the formulation aspect of air interface physical layer standard has obtained progress at present.

Loose backward compatibility (LBC at AIE, Loosely Backward Compatible) in the pattern, orthogonal frequency division multiplexi (OFDM, Orthogonal Frequency Division Multiplex) becomes the basic multiple access technology of AIE free from controvery with its technical advantage.Introduce the OFDM technology and make system's available resources become time domain and frequency domain two dimension resource pool, even add that code source becomes three-dimensional resource pool.OFDM self can eliminate in the sub-district and disturb, but can't eliminate presence of intercell interference, how to eliminate presence of intercell interference and improve Cell Edge User and (AT, Access Terminal) the OFDMA Traffic Channel that accesses terminal is carried out the key technology point that power control etc. becomes AIE.

When cell mobile communication systems adopted based on the Traffic Channel technology of OFDMA, key issue was the interference to adjacent cell of accessing terminal.

As shown in Figure 1, the Serving cell of AT1 is AP (Access Point) 1 (also can be referred to as the base station), when transmitting data on reverse traffic channel, interference has been caused in the sub-district of AP2 and AP3 covering.

The channel that existing AIE project LBC pattern comprises is as shown in Table 1:

Table one

In existing LBC scheme, AP is at the F-OSICH of forward direction superframe and the F-FOSICH channel is broadcasted OSI (other sector interference) information respectively and FOSI (Fast other sectorinterference) information is given the AT of adjacent cells, indicate the disturbed condition of suffered these AT in this sub-district, OSI only is included in each superframe head, FOSI has transmission in each frame of superframe, with respect to OSI, speed is faster, but coverage is littler than OSI.

The span of OSI, FOSI is ' 0 ', ' 1 ', ' 2 '.When base station measurement to certain sub-district IOT (interference over thermal) when being lower than the working point of expectation, the value of OSI, FOSI is 0; When IOT surpassed the working point of expectation, OSI, FOSI value were 1 or 2, the working point that has surpassed expectation that wherein the IOT value of 2 expression measurements is too much.

In the AP side, the OSI information of F-OSICH is modulated onto on the TDM PILOT (time-division pilot tone) of forward direction superframe head as phase information.The FOSI information of F-OSICH is modulated onto on 8 OFDM symbols in every frame.

U.S. Patent number US2006209721; in the disclosed technical scheme of denomination of invention Interference control in a wirelesscommunication system; AT directly adopts the OSI bit that receives that reverse traffic channel is carried out the power adjustment; this method two shortcomings are arranged: when (1) changes by 0 to 2 and 2 to 0 as OSI; the transmitting power of AT is adjusted step-length and may be had greatly changed; to around other sub-district can cause larger interference; (2) because OSI and FOSI information do not have error protection; AT separates timing may be because abominable wireless environment causes bit erroneous judgement and false-alarm; more than two shortcomings finally cause disturbing and can not effectively eliminate, to such an extent as to the decline of the reduction of power system capacity and systematic function.

Summary of the invention

Technical problem solved by the invention provides a kind of interference control method based on the OSI bit, improves the reliability of F-OSICH and F-FOSICH, reduces the bursty interference of AT to adjacent cells, has improved the performance of whole communication system.

Technical scheme is as follows:

Based on the interference control method of OSI bit, step is as follows:

(1) receives the OSI bit and the filter parameter of sub-district by eating dishes without rice or wine;

(2) terminal is carried out soft demodulation to the OSI bit information of making a start;

(3) according to the described filter parameter that receives, described soft OSI bit is carried out Filtering Processing by filter;

(4) adjust power step size according to the output valve of described filter.

Further, in the step (1), described filter parameter comprises timeconstant.

Further, in the step (3), the filter parameter according to receiving carries out Filtering Processing by filter to soft OSI bit.

Further, in the step (3), described filter adopts FIR filter or iir filter.

Further, step (4) is specially: according to the output valve of filter, adopt the method for hard decision, obtain the OSI value of hard decision, adjust power step size according to the OSI value of described hard decision.

Adopt the method for the invention, compared with prior art, improved the OSI information reliability, power control to terminal is more accurate, the power adjustment is more level and smooth, reduced the adjustment on a large scale of AT transmitting power and, improved the performance of whole communication system because the AT transmitting power mistake adjustment that the OSI erroneous judgement causes has reduced the bursty interference of AT to adjacent cells.

In a word, the inventive method can be controlled AT effectively interference is caused in other sub-district, can improve the reliability of OSI bit, suppress the strong fluctuating of OSI bit, Interference Control stably is provided, reduced interference, made system under safe and reliable prerequisite, improve the stability of a system and Interference Control performance to greatest extent, improved the capacity of system other sub-district.

Description of drawings

Fig. 1 is a communication system schematic diagram in the prior art;

Fig. 2 is the flow chart that the present invention carries out Interference Control.

Embodiment

With reference to the accompanying drawings, the preferred embodiments of the present invention are described in detail.

With reference to shown in Figure 2, after AT is linked into the base station, when the data of beginning Traffic Channel transmit, carry out the power adjustment of Traffic Channel according to following steps.

Step S201: the OSI bit and the filter parameter that receive the sub-district by eating dishes without rice or wine.

Filter parameter herein comprises timeconstant.

Step S202: terminal is carried out soft demodulation to the OSI bit information of making a start.

Step S203:, the soft OSI bit of importing is carried out Filtering Processing according to the described filter parameter that receives.

Can adopt FIR filter or iir filter that the soft OSI bit of input is carried out Filtering Processing.

Soft bit herein is meant the Bit data that obtains by soft demodulation.

Wherein, the iir filter example is as follows:

y(n)＝(1-1/τ)×y(n-1)+(1/τ)×x(n)

Wherein, x (n) is the soft OSI bit information of input, and τ is a time constant, and y (n) is the filter value of output.

Step S204: the output valve according to filter is adjusted transmitting power.

The data that obtain based on soft demodulation are data that comprise soft information such as decimal, need to obtain 0 or 1 actual bit value through hard decision, the OSI value that the hard decision method obtains is meant carries out threshold judgement to filtering data, gets 0,1 or 2 equivalences in different thresholding intervals.

According to the output valve of filter, adopt the method for hard decision, obtain the OSI value of hard decision, according to the hard decision result, adopt power control algorithm based on OSI, adjust transmitting power.

Claims

1. interference control method based on the OSI bit, step is as follows:

(1) indicates OSI bit and filter parameter by the load of air interface reception sub-district;

(2) the OSI bit information of making a start is carried out soft demodulation;

(3) according to the described filter parameter that receives, soft OSI bit is carried out Filtering Processing by filter;

(4) adjust power step size according to the output valve of described filter.

2. the interference control method based on the OSI bit according to claim 1 is characterized in that, in the step (1), described filter parameter comprises timeconstant.

3. the interference control method based on the OSI bit according to claim 2 is characterized in that, in the step (3), the filter parameter according to receiving carries out Filtering Processing by filter to soft OSI bit.

4. the interference control method based on the OSI bit according to claim 3 is characterized in that, in the step (3), described filter adopts FIR filter or iir filter.

5. the interference control method based on the OSI bit according to claim 1, it is characterized in that step (4) is specially:, adopt the method for hard decision according to the output valve of filter, obtain the OSI value of hard decision, adjust power step size according to the OSI value of described hard decision.