CN102843760B - Downlink power distributing method in a kind of LTE system - Google Patents

Abstract

The embodiment of the invention discloses the downlink power distributing method in a kind of Long Term Evolution LTE system.The method comprises: pre-determine out P _athe corresponding relation in value and PPR interval, wherein, adjacent PPR interval forms continuum jointly, if a P _avalue is greater than another P _avalue, so, this P _aany PPR value in the PPR interval that value is corresponding is less than this another P _aany PPR value in the PPR interval that value is corresponding; Determine the PPR value that UE is current, judge which PPR is this PPR value belong to interval, by interval for this PPR corresponding P _avalue distributes to this UE; According to the P distributed for this UE _avalue, determines the descending power value sending information to this UE.Application the present invention can improve the throughput of edge customer, improves the fairness between user.

Description

Downlink power distributing method in a kind of LTE system

Technical field

The present invention relates to communication technical field, particularly relate to the downlink power distributing method in a kind of Long Term Evolution (LTE) system.

Background technology

In LTE system, the power resource of downlink traffic channel manages by base station is unified.The descending power size of base station service UE is by parameter P _a, P _bjointly determine with downlink reference signal power.Wherein P _bbe cell-level parameter with downlink reference signal power, broadcast in the cell.P _avalue is UE special parameter, reflect base station assigns to every resource particle (Resource Element of the DSCH Downlink Shared Channel (PDSCH) in the type A OFDM symbol of UE, RE) energy (Energy Per RE, EPRE) with the ratio of the EPRE of cell reference signals, the P of each UE will be distributed to by layer three signaling in base station _avalue informs each UE.Therefore, under certain cell configuration, P is determined _avalue just can determine the down transmitting power of UE.

At present, P is defined in agreement _aspan be {-6 ,-4.77 ,-3 ,-1.77,0,1,2,3}.

Downlink power distributing method common in LTE system is, the UE different to each arranges identical down transmitting power, and namely base station is that all UE that it is administered configure identical P _avalue.

There is following defect in described common downlink power distributing method:

Residing for UE, geographical position is different, the available power received and institute's disturbed area not very large, therefore, when the UE for being in diverse geographic location arranges identical down transmitting power, for comparatively large and be subject to the UE of adjacent cell interference at cell edge path loss, received signal to noise ratio is lower, cause the user throughput of cell edge lower, and it is less and by the less UE of adjacent cell interference for center of housing estate path loss, received signal to noise ratio is higher, but signal to noise ratio cannot improve the user throughput in center of housing estate region further when being greater than certain threshold value, and, if take excessive transmitting power, also can cause larger interference to adjacent cell UE.Visible, for each UE in same community distributes identical descending power, and the signal to noise ratio difference of each UE is larger in same community, cause the throughput differences of the throughput of center of housing estate and cell edge larger, the service performance that the UE of center of housing estate and the UE of cell edge obtains differs greatly, and the fairness between UE is poor.

Summary of the invention

In view of this, the invention provides the downlink power distributing method in a kind of LTE system, to improve the user throughput of cell edge.

Technical scheme of the present invention is specifically achieved in that

A downlink power distributing method in Long Term Evolution LTE system, the method comprises:

Pre-determine out P _athe corresponding relation in value and PPR interval, wherein, adjacent PPR interval forms continuum jointly, if a P _avalue is greater than another P _avalue, so, this P _aany PPR value in the PPR interval that value is corresponding is less than this another P _aany PPR value in the PPR interval that value is corresponding;

Determine the PPR value that UE is current, judge which PPR is this PPR value belong to interval, by interval for this PPR corresponding P _avalue distributes to this UE;

According to the P distributed for this UE _avalue, determines the descending power value sending information to this UE;

Wherein, P _avalue is base station assigns to the ratio of the EPRE of every RE ENERGY E PRE of the DSCH Downlink Shared Channel PDSCH in the type A OFDM symbol of UE and cell reference signals;

PPR value calculates according to the Reference Signal Received Power RSRP value of UE Serving cell and the RSRP value of UE adjacent cell.

As seen from the above technical solution, the present invention is previously determined P _athe corresponding relation in value and PPR interval, and, P _abe worth larger, this P _athe PPR value that the PPR interval of value correspondence comprises is less, interval by determining the PPR at the PPR value place that UE is current, by interval for this PPR corresponding P _avalue distributes to this UE, achieve UE PPR value more hour, distribute to the P of UE _abe worth larger.

PPR value is wherein the difference that the RSRP value of Serving cell deducts the RSRP mean value gained of the N number of most strong jamming adjacent area of this UE, reflect the signal to noise ratio of UE to a certain extent, usually, the signal to noise ratio being positioned at the UE of center of housing estate is higher, corresponding PPR value is larger, by the present invention, distribute less P by the UE for being positioned at center of housing estate _avalue, and distance center of housing estate is far away, the PPR value of UE is general less, and the present invention is that these UEs far away apart from center of housing estate distribute relatively large P _avalue, the PPR value being generally positioned at the UE of cell edge is minimum, and the UE therefore for being positioned at cell edge distributes maximum P _avalue.

Visible, by the present invention, the transmitting power of UE is increased along with the rising of this community path loss and interference level, and the UE being positioned at community diverse location can both obtain good service performance, therefore, it is possible to improve the fairness between user, improve the user throughput of cell edge.

Accompanying drawing explanation

Fig. 1 is the downlink power distributing method flow chart in LTE system provided by the invention.

Fig. 2 is the downlink power distributing method flow chart under mobile context provided by the invention.

Embodiment

Fig. 1 is the downlink power distributing method flow chart in LTE system provided by the invention.

As shown in Figure 1, the method comprises:

Step 101, pre-determines out P _athe corresponding relation in value and PPR interval.

Wherein, P _avalue is that base station assigns is to the ratio of every RE energy (EPRE) of the DSCH Downlink Shared Channel (PDSCH) in the type A of UE (type A) OFDM symbol with the EPRE of cell reference signals; PPR value is the difference that Reference Signal Received Power (RSRP) value of UE Serving cell deducts the RSRP mean value gained of the N number of most strong jamming adjacent area of this UE.

Wherein, adjacent PPR interval forms continuum jointly, if a P _avalue is greater than another P _avalue, so, this P _aany PPR value in the PPR interval that value is corresponding is less than this another P _aany PPR value in the PPR interval that value is corresponding.

In other words, P _athe corresponding relation in value and PPR interval should meet following two conditions:

Condition one, if a PPR value is greater than another PPR value, then the P that this PPR value is corresponding _avalue should be not more than P corresponding to this another PPR value _avalue.

Condition two, each PPR value can both map out unique P _avalue.

Step 101 is pre-treatment step, determines P _aafter the corresponding relation in value and PPR interval, this corresponding relation can be stored in network side, be that UE distributes P at every turn _aduring value, can directly perform from step 102.

Step 102, the Serving cell RSRP value that network side reports according to UE and adjacent area RSRP value determine the PPR value that UE is current.

In this step, the difference that the RSRP value of UE Serving cell is deducted the RSRP mean value gained of the N number of most strong jamming adjacent area of this UE by network side is defined as the PPR value of this UE.

Network side determines that the formula of the PPR value of UE is specifically as follows:

$\mathrm{PPR}\left(i\right)=\mathrm{RSR}{P}_{\mathrm{Serving}}\left(i\right)-\frac{1}{N}\underset{n=1}{\overset{N}{\mathrm{\Σ}}}{\mathrm{RSRP}}_{\mathrm{StrongestNeighbour}}(i,n)$

Wherein, PPR (i) is UE _ipPR value, RSRP _serving(i) and RSRP _{strongestNeighbour}(i, n) is respectively UE _ireceive the RSRP value from Serving cell and the n-th strong jamming adjacent area.

N value wherein can be 1.Preferably, N value is not less than 2.When N value is not less than 2, PPR value can reflect that the actual of UE is disturbed level more exactly.

Step 103, it is interval that network side judges which PPR is the current PPR value of this UE belong to, by interval for this PPR corresponding P _avalue distributes to this UE.

Step 104, network side is according to the P distributed for this UE _avalue, determines the descending power value sending information to this UE.

In method shown in Fig. 1, P _athe corresponding relation in value and PPR interval can be linear, specifically can determine P according to formula y=-kx+b _athe corresponding relation in value and PPR interval, wherein, k and b is datum, and k > 0, y is discrete P _avalue, P _athe span of value is specifically as follows { 3,2,1,0 ,-1.77 ,-3 ,-4.77 ,-6}.

Determine that the method for described corresponding relation specifically can comprise according to y=-kx+b:

By P _aeach value substitute into formula y=-kx+b, according to P _athe value of value and k, b is determined and the value of x the value of this x is defined as this P _athe higher limit in the PPR interval that value is corresponding, by this P _athe lower limit in the PPR interval that value is corresponding is defined as than this P _athe P of value higher order _athe higher limit of value, most high-order P _athe lower limit of value is minus infinity or is preset value, lowest-order P _athe upper limit of value is positive infinity or is another preset value.

By the value of the parameter k in adjustment formula y=-kx+b and b, P can be adjusted _athe PPR interval range that value is corresponding.According to cell scenario and user distribution situation, reasonable parameters k and b, in adjustment community, the power distribution of UE, can reach the balance of edge performance and overall performance.Particularly, k value is larger, and PPR interval is less, and k value is less, and PPR interval is larger; B value is larger, configures identical P _athe PPR threshold value of value correspondence is higher, configuration high power P _athe user of value is more, otherwise b value is less, configuration low-power P _athe user of value is more.

Invention also contemplates that user mobility scene, because when customer location change causes signal quality and interference to change, down transmitting power should be adjusted accordingly, the invention provides the corresponding flow process of down transmitting power configuration change, also can reach the effect promoting edge user throughput under making descending power be configured in the scene of user's movement, specifically refer to Fig. 2.

Fig. 2 is the downlink power distributing method flow chart under mobile context provided by the invention.

As shown in Figure 2, the method comprises:

Step 201, network side receives the RSRP value of the N number of most strong jamming adjacent area of the RSRP value of Serving cell that UE reports and this UE.

Step 202, network side calculates the current PPR value of this UE according to the RSRP value of the N number of most strong jamming adjacent area of the RSRP value of the up-to-date Serving cell reported of this UE and this UE.

Step 203, the PPR value of this UE that network side goes out according to latest computed, by interval for the PPR at this PPR value place corresponding P _avalue is defined as the P of latest computed _avalue.

Step 204, network side judges the P of this latest computed _avalue and the last P distributing to this UE _awhether be identically worth, if identical, perform step 205, if not identical, perform step 206.

Step 205, keeps the P distributing to this UE _abe worth constant, return step 201.

Step 206, network side will distribute to the P of this UE _avalue is updated to the P of this latest computed _avalue, and by the P of this latest computed _avalue issues UE.

In this step, network side can by layer three signaling by the P of latest computed _avalue issues UE.

Especially, if network side does not receive the RSRP value of UE Serving cell or adjacent cell in time, network side can be UE and arranges default P _avalue, this parameter is the default parameter of cell-level configuration.

Visible, downlink power distributing method provided by the invention is the P that user's configuration of center of housing estate is lower _avalue is the P that Cell Edge User configuration is higher _avalue, P _avalue mapping method receives this community RSRP based on UE and receives the difference of adjacent cell RSRP and arrange, and the transmitting power of UE is increased along with the rising of this community path loss and interference level.

For Cell Edge User, owing to being provided with higher transmitting power, carry out frequency selective scheduling simultaneously in base station and select the resource that interference power is less to send data, signal to noise ratio is improved, thus improves the throughput of this part user; And for Cell Center User, because signal to noise ratio is in higher level, suitably reduce transmitting power less to its performance impact.This programme ensures that while promoting marginal user performance the hydraulic performance decline of central user is little, reaches the compromise of edge performance and overall performance.

The present invention is when in conjunction with interference coordination, and between adjacent cell, high power frequency band staggers, and edge customer, at high power frequency band scheduling, avoids the strong jamming that adjacent cell high power frequency band causes, and effectively can promote the throughput of edge customer.

In addition, preferably, the criterion of the measurement UE interference level that the present invention relates to considers several most strong jamming adjacent cell and combines the overall interference situation caused user, can reflect the actual level that is disturbed of UE more exactly, it can be used as configurating downlink power P _athe foundation of value, the reasonability that guaranteed output distributes, thus promote marginal user performance, ensure that overall performance declines little.

The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment made, equivalent replacement, improvement etc., all should be included within the scope of protection of the invention.

Claims (6)

1. the downlink power distributing method in Long Term Evolution LTE system, it is characterized in that, the method comprises:

Pre-determine out P _athe corresponding relation in value and PPR interval, wherein, adjacent PPR interval forms continuum jointly, if a P _avalue is greater than another P _avalue, so, this P _aany PPR value in the PPR interval that value is corresponding is less than this another P _aany PPR value in the PPR interval that value is corresponding;

Determine the PPR value that UE is current, judge which PPR is this PPR value belong to interval, by interval for this PPR corresponding P _avalue distributes to this UE;

According to the P distributed for this UE _avalue, determines the descending power value sending information to this UE;

Wherein, P _avalue is base station assigns to the ratio of the EPRE of every RE ENERGY E PRE of the DSCH Downlink Shared Channel PDSCH in the type A OFDM symbol of UE and cell reference signals;

PPR value calculates according to the Reference Signal Received Power RSRP value of UE Serving cell and the RSRP value of UE adjacent cell;

Describedly pre-determine out P _athe corresponding relation in value and PPR interval comprises:

P is determined according to y=-kx+b _athe corresponding relation in value and PPR interval;

Wherein, k>0, y are discrete P _avalue, according to P _athe value of value and k, b is determined and the value of x the value of this x is defined as this P _athe higher limit in the PPR interval that value is corresponding, by this P _athe lower limit in the PPR interval that value is corresponding is defined as than this P _athe P of value higher order _athe higher limit of value, most high-order P _athe lower limit of value is minus infinity or is preset value, lowest-order P _athe upper limit of value is positive infinity or is another preset value;

The current PPR value of the described UE of determining comprises:

Network side receives the RSRP value of the N number of most strong jamming adjacent area of the RSRP value of Serving cell that UE reports and this UE, and the RSRP value according to the N number of most strong jamming adjacent area of the RSRP value of the up-to-date Serving cell reported of this UE and this UE calculates the current PPR value of this UE;

The described PPR value calculating this UE current comprises:

The difference Reference Signal Received Power RSRP value of UE Serving cell being deducted the RSRP mean value gained of the N number of most strong jamming adjacent area of this UE is defined as the current PPR value of this UE;

Described by interval for this PPR corresponding P _avalue is distributed to this UE and is comprised:

The PPR value of this UE that network side goes out according to latest computed, by interval for the PPR at this PPR value place corresponding P _avalue is defined as the P of latest computed _avalue, judges the P of this latest computed _avalue and the last P distributing to this UE _awhether be identically worth, if identical, keep the P distributing to this UE _abe worth constant, if not identical, will the P of this UE be distributed to _avalue is updated to the P of this latest computed _avalue, and by the P of this latest computed _avalue issues UE.

2. method according to claim 1, is characterized in that, the method also comprises:

The value of k and b is set according to the user distribution situation in cell scenario and/or community.

3. method according to claim 2, is characterized in that, the value of the described k of setting and b comprises:

In community, the PPR Distribution value scope of different UEs is larger, and what k value arranged is less;

And/or, configure identical P _athe PPR threshold value of value correspondence is higher, and what b value arranged is larger.

4. method according to claim 1, is characterized in that,

P _athe span of value comprises { 3,2,1,0 ,-1.77 ,-3 ,-4.77 ,-6}.

5. method according to claim 1, is characterized in that,

Described N be 1 or N be not less than 2.

6. method according to claim 1, is characterized in that, the method also comprises:

If network side does not receive the RSRP value of the Serving cell that UE reports or the RSRP value of adjacent area within the time period of predetermined length, network side is by the P of this UE _avalue is set to default P _avalue.