CN103581959A

CN103581959A - Method, equipment and system for improving downlink coverage of cell

Info

Publication number: CN103581959A
Application number: CN201210264099.7A
Authority: CN
Inventors: 刘劲楠
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2012-07-27
Filing date: 2012-07-27
Publication date: 2014-02-12
Anticipated expiration: 2032-07-27
Also published as: WO2014015684A1; CN103581959B

Abstract

The embodiment of the invention provides a method, equipment and system for improving downlink coverage of a cell, and relates to the field of communication. The method, equipment and system for improving downlink coverage of the cell solve the problem that downlink coverage of the cell is insufficient. The method comprises the steps that a base station determines UE with limited downlink coverage, a downlink loss value from the base station to the UE is obtained and a coverage compensation parameter is obtained according to the downlink loss value; the base station executes the coverage compensation process according to the coverage compensation parameter and sends the coverage compensation parameter to the UE through a physical layer signaling or a high layer signaling or the combination of the physical layer signaling and the high layer signaling so that the UE can demodulate the received data according to the coverage compensation parameter. The method, equipment and system are used for improving downlink coverage of the cell.

Description

A kind of method, apparatus and system of improving cell downlink covering

Technical field

The present invention relates to the communications field, relate in particular to a kind of method, apparatus and system that cell downlink covers of improving.

Background technology

Modern wireless communication systems, more and more emphasize spectrum efficiency and the support to large data throughput, as third generation partner program (3rd Generation Partnership Project, 3GPP) research, Long Term Evolution (the Long Term Evaluation of design, LTE) system, Institute of Electrical and Electric Engineers (Insititute of Electrical and Electronics Engineers, IEEE) World Interoperability for Microwave Access, WiMax ((the World Interoperability forMicrowave Access of research, WiMAX) system etc., its maximum data speed can reach 100Mbps.

But, because the type of service of transmitting has determined the size of transmit information data and the delay requirement of transmission, therefore, for different transport service types, these systems, when emphasizing the transmission that large data are handled up greatly, may exist the user of specific time delay, special speed is covered to not enough situation.

Summary of the invention

Embodiments of the invention provide a kind of method, apparatus and system that cell downlink covers of improving, and to solve cell downlink, cover not enough problem.

First aspect, provides a kind of method that cell downlink covers of improving, and comprising:

The terminal UE that descending covering is limited is determined in base station;

Described base station obtains from described base station to the descending circuit loss value of described UE, and obtains covering compensating parameter according to described descending circuit loss value;

Described base station is carried out and is covered compensation process according to described covering compensating parameter, and by the combination of physical layer signaling or high-level signaling or described physical layer signaling and described high-level signaling, to described UE, send described covering compensating parameter, so that described UE carries out demodulation according to described covering compensating parameter to the data that receive.

In the possible implementation of first aspect the first, described physical layer signaling comprises Downlink Control Information DCI signaling;

Described high-level signaling comprises radio resource control RRC signaling;

The combination of described physical layer signaling and high-level signaling comprises the combination of using DCI signaling and RRC signaling.

In conjunction with first aspect or the possible implementation of first aspect the first, in the possible implementation of the second, the UE that descending covering is limited is determined in described base station, specifically comprises:

Described base station receives the wrong responses NACK of described UE feedback, and when being defined as modulation that described UE distributes and encoding scheme MCS and being the lowest class, determines that the descending covering of described UE is limited.

In conjunction with first aspect, to the possible implementation of first aspect the second, in the third possible implementation, described base station obtains from described base station to the descending circuit loss value of described UE, specifically comprises:

Base station receives the channel quality indicator (CQI) value of described UE feedback, and passes through formula according to described CQI value: P _l=P _s-P _r, calculate described descending circuit loss value; Wherein, P _lfor described descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, P _r=SNR+N, wherein, P _rfor the received power value of described UE in downlink traffic channel, SNR is signal to noise ratio corresponding to described CQI value, the noise power that N is each carrier wave; Or,

Base station receives the reference signal power value that UE measurement reports, and passes through formula according to the performance number of described reference signal: P _l=P _s-P _rSRP, calculate described descending circuit loss value; Wherein, P _lfor described descending circuit loss value, P _sfor the performance number that described downlink reference signal is launched in base station, P _rSRPdescribed reference signal power value for described UE reception; Or,

Base station receives the descending circuit loss value reporting after described UE measures.

In conjunction with first aspect, to the third possible implementation of first aspect, in the 4th kind of possible implementation, describedly according to described descending circuit loss value, obtain covering compensating parameter, specifically comprise:

Pass through formula: N _s=R _s+ P _l-P _s+ Δ, calculates and covers compensating factor, and obtain covering compensating parameter according to described covering compensating factor; Wherein, N _sfor described covering compensating factor, P _lfor described descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, R _sthe MCS using in Traffic Channel for described UE is the receiving sensitivity under the lowest class, and Δ is preset value, is nonnegative real number.

In conjunction with the 4th kind of possible implementation of first aspect, in the 5th kind of possible implementation, also comprise: when definite described covering compensating factor is negative, returns and re-execute the described step of determining the UE that descending covering is limited.

In conjunction with the 4th kind of possible implementation of first aspect or the 5th kind of possible implementation, in the 6th kind of possible implementation, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: according to described covering compensating factor, adjust mixed automatic retransfer request HARQ maximum retransmission;

Described according to described covering compensating parameter execution covering compensation process, comprising:

Utilize the HARQ maximum retransmission after described adjustment to upgrade former HARQ maximum retransmission.

In conjunction with the 4th kind of possible implementation of first aspect or the 5th kind of possible implementation, in the 7th kind of possible implementation, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: pass through formula: calculate repetition factor, wherein, N _pfor described repetition factor, N _sfor described covering compensating factor;

Information bit before each coding is done to N _pdoubly repeat; Or,

Data bit after whole coding is done to N _pdoubly repeat; Or,

Symbol after all modulation is done to N _pdoubly repeat.

In conjunction with the 4th kind of possible implementation of first aspect or the 5th kind of possible implementation, in the 8th kind of possible implementation, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: pass through formula:

calculate spreading factor, wherein, N _pfor described spreading factor, N _sfor described covering compensating factor;

By frequency expansion sequence, the symbol after modulating is carried out to N _pdirect sequence spread spectrum doubly.

In conjunction with eight kinds of possible implementations of the 4th kind of possible implementation to the of first aspect, in the 9th kind of possible implementation, at described UE, according to described covering compensating parameter, the data that receive are carried out, after demodulation, also comprising:

If what described base station received described UE feedback correctly replys ACK, described base station is calculated covering compensating factor again, and again obtain covering compensating parameter according to the described covering compensating factor again calculating, and carry out described covering compensation process according to the described covering compensating parameter again obtaining;

If described base station receives the NACK of described UE feedback, by adjusting described preset value, adjust described covering compensating factor.

In conjunction with first aspect to the 9th kind of possible implementation of first aspect, in the tenth kind of possible implementation, described covering compensating parameter comprises: HARQ maximum retransmission or repetition factor or spreading factor and the parameter that generates frequency expansion sequence necessity.

Second aspect, provides a kind of base station, comprising:

Processing unit, for determining the limited UE of descending covering, obtains from described base station to the descending circuit loss value of described UE, and obtains covering compensating parameter according to described descending circuit loss value, and carry out and cover compensation process according to described covering compensating parameter;

Transmitting element, for by the combination of physical layer signaling or high-level signaling or described physical layer signaling and described high-level signaling, sends described covering compensating parameter to described UE, so that described UE carries out demodulation according to described covering compensating parameter to the data that receive.

In the possible implementation of second aspect the first, described physical layer signaling comprises Downlink Control Information DCI signaling;

Described high-level signaling comprises radio resource control RRC signaling;

In conjunction with second aspect or the possible implementation of second aspect the first, in the possible implementation of the second, also comprise:

Receiving element, after the data that send in base station described in described UE demodulation, receives the wrong responses NACK of described UE feedback;

Described processing unit specifically for, at described receiving element, receive after described NACK, and described processing unit is when being defined as modulation that described UE distributes and encoding scheme MC S and being the lowest class, determines that the descending covering of described UE is limited.

In conjunction with second aspect, to the possible implementation of second aspect the second, in the third possible implementation, described receiving element is specifically for receiving the channel quality indicator (CQI) value of described UE transmission;

Described processing unit, specifically for receiving at described receiving element after described CQI value, passes through formula according to described CQI value: P _l=P _s-P _r, calculate described descending circuit loss value; Wherein, P _lfor described descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, P _r=SNR+N, wherein, P _rfor the received power value of described UE in downlink traffic channel, SNR is signal to noise ratio corresponding to described CQI value, the noise power that N is each carrier wave; Or,

The reference signal power value that described receiving element reports specifically for receiving UE measurement;

Described processing unit, specifically for receiving after described reference signal power value at described receiving element, passes through formula according to the performance number of described reference signal: P _l=P _s-P _rSRP, calculate described descending circuit loss value; Wherein, P _lfor described descending circuit loss value, P _sfor the performance number that described downlink reference signal is launched in base station, P _rSRPdescribed reference signal power value for described UE reception; Or,

Described receiving element is specifically for receiving the descending circuit loss value reporting after described UE measures.

In conjunction with second aspect, to the third possible implementation of second aspect, in the 4th kind of possible implementation, described processing unit is specifically for passing through formula: N _s=R _s+ P _l-P _s+ Δ, calculates and covers compensating factor, and obtain covering compensating parameter according to described covering compensating factor; Wherein, N _sfor described covering compensating factor, P _lfor described descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, R _sthe MCS using in Traffic Channel for described UE is the receiving sensitivity under the lowest class, and Δ is preset value, is nonnegative real number.

In conjunction with the 4th kind of possible implementation of second aspect, in the 5th kind of possible implementation, described processing unit, also for when definite described covering compensating factor is negative, returns and re-executes the described limited UE of descending covering of determining.

In conjunction with the 4th kind of possible implementation of second aspect or the 5th kind of possible implementation, in the 6th kind of possible implementation, described processing unit is specifically for adjusting HARQ maximum retransmission according to described covering compensating parameter, and utilizes the HARQ maximum retransmission after described adjustment to upgrade former HARQ maximum retransmission.

In conjunction with the 4th kind of possible implementation of second aspect or the 5th kind of possible implementation, in the 7th kind of possible implementation, described processing unit is specifically for passing through formula:

calculate repetition factor, wherein, N _pfor described repetition factor, N _sfor described covering compensating factor; Described processing unit is concrete also for the information bit before each coding is done to N _pdoubly repeat; Or, the data bit after whole coding is done to N _pdoubly repeat; Or, the symbol after all modulation is done to N _pdoubly repeat.

In conjunction with the 4th kind of possible implementation of second aspect or the 5th kind of possible implementation, in the 8th kind of possible implementation, described processing unit is specifically for passing through formula:

calculate spreading factor, wherein, N _pfor described spreading factor, N _sfor described covering compensating factor, and by frequency expansion sequence, the symbol after modulating is carried out to N _pdirect sequence spread spectrum doubly.

In conjunction with eight kinds of possible implementations of the 4th kind of possible implementation to the of second aspect, in the 9th in possible implementation, described receiving element, also for the data that receive being carried out after demodulation according to described covering compensating parameter at described UE, receives ACK or the NACK of described UE feedback;

If described processing unit also receives the ACK of described UE feedback for described receiving element, again calculate and cover compensating factor, and again obtain covering compensating parameter according to the described covering compensating factor again calculating, and carry out described covering compensation process according to the described covering compensating parameter again obtaining; If described receiving element receives the NACK of described UE feedback, by adjusting described preset value, adjust described covering compensating factor.

In conjunction with second aspect to the 9th kind of possible implementation of second aspect, in the tenth kind of possible implementation, described covering compensating parameter comprises: HARQ maximum retransmission or repetition factor or spreading factor and the parameter that generates frequency expansion sequence necessity.

The third aspect, provides a kind of communication system, comprising: base station and terminal,

Described base station is the base station described in second aspect;

The covering compensating parameter that described terminal sends for receiving described base station, and according to described covering compensating parameter, the data that receive are carried out to demodulation, and to described base station feedback ACK or NACK.

Adopt such scheme, base station is carried out and is covered compensation process according to the covering compensating parameter obtaining, and this covering compensating parameter is sent to UE, with limit UE, according to this covering compensating parameter, the data that receive are carried out to demodulation, like this, the enhancing that base station can cover covering limited users, covers not enough problem thereby solved cell downlink.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, to the accompanying drawing of required use in embodiment or description of the Prior Art be briefly described below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skills, do not paying under the prerequisite of creative work, can also obtain according to these accompanying drawings other accompanying drawing.

A kind of method schematic diagram that improves cell downlink covering that Fig. 1 provides for the embodiment of the present invention;

The another kind that Fig. 2 provides for the embodiment of the present invention improves the schematic flow sheet of cell downlink covering method;

The structural representation of a kind of base station that Fig. 3 provides for the embodiment of the present invention;

The structural representation of the another kind of base station that Fig. 4 provides for the embodiment of the present invention;

A kind of communication system that Fig. 5 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is clearly and completely described, obviously, described embodiment is only the present invention's part embodiment, rather than whole embodiment.Embodiment based in the present invention, those of ordinary skills, not making the every other embodiment obtaining under creative work prerequisite, belong to the scope of protection of the invention.

The embodiment of the present invention provides a kind of method that cell downlink covers of improving, and as shown in Figure 1, the executive agent of the method is base station, and the method comprises:

The limited UE of descending covering (User Equipment, subscriber equipment, i.e. terminal) is determined in S101, base station.

Alternatively, after the data that send in this base station of UE demodulation, this base station receives the NACK (wrong responses) of this UE feedback, and at MCS (the Modulation and Coding Scheme that is defined as this UE distribution, modulation and encoding scheme) while being the lowest class, determine that the descending covering of this UE is limited.The limited UE of descending covering is exactly the elementary UE of MCS.

Particularly, because the lower grade of MCS, corresponding spectrum efficiency is lower, SINR (the Signal to Interference plus Noise Ratio of work, Signal to Interference plus Noise Ratio) just lower, the downlink transfer distance that base station can be supported is far away, therefore, when base station is defined as MCS that this UE distributes and is the lowest class, represent that the downlink transfer distance that can support base station has reached maximum distance, if now base station still receives the NACK of this UE feedback, represent that this maximum distance also cannot guarantee that UE carries out correct demodulation, determine that the descending covering of this UE is limited.

For example, in LTE system, MCS is defined as follows shown in table:

MCS grade	Modulation system	Code check * 1024	Spectrum efficiency
				0	-	-	-
1	QPSK	78	0.1523
				2	QPSK	120	0.2344
3	QPSK	193	0.3770
				4	QPSK	308	0.6016
5	QPSK	449	0.8770
				6	QPSK	602	1.1758

7	16QAM	378	1.4766
				8	16QAM	490	1.9141
9	16QAM	616	2.4063
				10	64QAM	466	2.7305
11	64QAM	567	3.3223
				12	64QAM	666	3.9023
13	64QAM	772	4.5234
				14	64QAM	873	5.1152
15	64QAM	948	5.5547

In table, defined altogether MCS grade in 15, i.e. MCS1 to MCS15 (MCS0 does not define in LTE system), MCS1 is the lowest class, MCS15 is highest ranking.Base station receives CQI (indication of the Channel quality Indicator channel quality) value that UE reports, and the CQI value reporting according to UE and the grade for this UE distribution MCS to the measurement result of up channel, if base station is when the grade of the MCS distributing for this UE is MCS1, and receiving UE is NACK to the response feedback of downlink data HARQ (Hybrid Automatic Repeat-reQuest mixes automatically and repeat requests), determine that the descending covering of this UE is limited, wherein, CQI value has been indicated the grade of the MCS that UE reports.Here the explanation that the LTE system of just take is carried out as example, as concrete restriction.

S102, base station obtain from this base station to the descending circuit loss value of UE, and obtain covering compensating parameter according to this descending circuit loss value.

Obtaining descending circuit loss value specifically can obtain by either type in following three kinds of modes:

Mode one: base station receives the CQI of this UE feedback, and passes through formula according to this CQI value: P _l=P _s-P _r, calculate this descending circuit loss value.

Wherein, P _lfor this descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, P _r=SNR+N, wherein, P _rfor the received power value of this UE in downlink traffic channel, SNR (Signal-to-Noise Ratio, signal to noise ratio) is signal to noise ratio corresponding to this CQI value, the noise power that N is each carrier wave.

For example, in LTE system, if the MCS grade of the CQI that UE reports indication is MCS4, and when definite Block Error Rate is percent 10, the SNR that MCS is corresponding is-2.2dB, and N is the noise power on each 15khz carrier wave, and N=-174+101g (15 * 10 ³)=-132.24, can obtain: P _r=SNR+N=-2.2-132.24=-134.44dBm, if P _sfor 40dBm, by above-mentioned formula, can be obtained: descending circuit loss value P _l=P _s-P _r=40-(134.44)=174.44dB.

Mode two: base station receives the reference signal power value that UE measurement reports, and passes through formula according to the performance number of this reference signal: P _l=P _s-P _rSRP, calculate this descending circuit loss value.

Wherein, P _lfor this descending circuit loss value, P _sfor the performance number that this downlink reference signal is launched in base station, P _rSRPthis reference signal power value for this UE reception.

For example,, in LTE system, if the P that UE measures on CRS (Cell-specific Reference Signal cell specific reference signal) _rSRPfor-100dBm, the transmission power level P of base station on CRS _sfor 40dBm.UE will be the P of CRS in mobility measurements report _rSRPby up message report to base station.Descending circuit loss value P can be calculated by formula below in base station _l:

P _L＝P _S-P _RSRP＝40-(-100)＝140dB。

Mode three: base station receives the descending circuit loss value reporting after UE measures.

Be that calculating in mode two also can be carried out in UE side, at UE, calculate descending circuit loss value P _l=P _s-P _rSRPafter=40-(100)=140dB, this UE is by the P calculating _lvalue sends to base station by upstream message.

It should be noted that, aforesaid way one need to suppose that UE is only subject to AWGN (Additive White Gaussion Noise, additive white Gaussian noise) interference, and be not subject to the interference of other homogenous frequency signals, therefore result of calculation is a perfect condition value, and under the scene of frequently disturbing at multiple sectors at same, error is larger, therefore, in actual applications, preferably adopt mode two or mode three to obtain descending circuit loss value.

In addition, after obtaining this descending circuit loss value, formula is passed through according to this descending circuit loss value in base station: N _s=R _s+ P _l-P _s+ Δ, calculates this covering compensating factor, and obtains covering compensating parameter according to this covering compensating factor.

Wherein, N _sfor this covers compensating factor, unit is dB, P _lfor this descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, R _sthe MCS using in Traffic Channel for this UE is the receiving sensitivity under the lowest class, and Δ is preset value, is nonnegative real number.

For example,, in LTE system, if R _sfor-100dBm, P _lfor 160dB, P _sfor 40dBm, according to above-mentioned formula: N _s=R _s+ P _l-P _s+ Δ, can obtain N _s=10+ Δ, that is to say, N _s>=10dB, but in order to improve the service efficiency of transmission channel, introduce a preset value Δ, this preset value Δ can arrange according to practical application or empirical value, and its effect is under wireless channel conditions, gives the covering compensating factor N that needs compensation _swhen reality is used, provide certain protection to measure in advance, to this preset value Δ, the present invention is not construed as limiting, and like this, adjusts preset value Δ can, when guaranteeing enough descending coverings, improve the service efficiency of transmission channel by base station.

Further, if when the definite covering compensating factor obtaining in base station is negative, returns and re-execute the described step of determining the UE that descending covering is limited, if the UE reaffirming is still this UE, illustrate that this UE is in the situation that power is enough, still can not carry out correct demodulation, determine that this UE is abnormal.

In addition, base station obtains covering compensating parameter according to covering compensating factor and comprises following three kinds of modes, and the present invention is not construed as limiting this:

Mode one: base station covers compensating parameter according to this and adjusts HARQ (Hybrid Automatic Repeat Request, mixed automatic retransfer request) maximum retransmission.

Wherein, gain corresponding to this HARQ maximum retransmission meets this covering compensating parameter.

For example, in LTE system, if HARQ maximum retransmission is 4 times, and it is 6dB that 4 HARQ retransmit corresponding gain, but needing to cover covering compensating parameter corresponding to compensation is 10dB, maximum re-transmission for 4 times still can not meet the requirement that covers expansion, therefore HARQ maximum retransmission can be adjusted into and be greater than 4 times, as 6 times or 8 times, to meet the requirement that covers expansion.

It should be noted that, gain corresponding to above-mentioned HARQ maximum retransmission is that the grade of MCS and the mapping table of gain that UE distributes obtains by base station by inquiry base station; Or, according to practical experience, obtain, for example, the gain of the different number of retransmissions that the grade of different MCS is corresponding is known in base station by modes such as link simulation, instrument tests, thereby obtain to meet according to gain, cover the HARQ maximum retransmission that expansion requires.

Mode two: formula is passed through in base station calculate repetition factor.

Wherein, N _pfor repetition factor, N _sfor covering compensating factor.

Mode three: formula is passed through in base station:

calculate spreading factor.

Wherein, N _pfor spreading factor, N _sfor covering compensating parameter; This frequency expansion sequence is the concentrated a row or column of arbitrary frequency expansion sequence.For example, N _p=4 o'clock, Spread Spectrum Sequence Set can be that following length is 4 matrix H:

H = [\begin{matrix} + 1 & + 1 & + 1 & + 1 \\ + 1 & - 1 & + 1 & - 1 \\ + 1 & + 1 & - 1 & - 1 \\ + 1 & - 1 & - 1 & + 1 \end{matrix}]

Length is that 4 frequency expansion sequence can be to appoint a row or column in matrix H above.The call parameter that generates frequency expansion sequence in this example is frequency expansion sequence length N _pand the number value of the row or column of frequency expansion sequence.

For another example,, if frequency expansion sequence is Zadoff-Chu sequence, long is N _pthe generation formula of certain frequency expansion sequence is:

x_{q} (m) = e^{- j \frac{πqm (m + 1)}{N_{p}}}, 0 \leq m \leq N_{p} - 1

The call parameter that generates frequency expansion sequence in this example is frequency expansion sequence length N _pand sequence number q.

Covering compensation process is carried out according to covering compensating parameter in S103, base station, and by the combination of physical layer signaling or high-level signaling or this physical layer signaling and this high-level signaling, to this UE, send this covering compensating parameter, so that this UE carries out demodulation according to this covering compensating parameter to the data that receive.

Wherein, concrete covering compensation process comprises following three kinds of modes, and the present invention is not construed as limiting this:

Mode one: base station utilizes the HARQ maximum retransmission after described adjustment to upgrade former HARQ maximum retransmission.

Further, above-mentioned base station to UE transmission covering compensating parameter tool can be: base station sends this HARQ maximum retransmission to this UE, so that this UE, before HARQ number of retransmissions reaches HARQ maximum retransmission, carries out buffer memory or merging by the data of demodulation mistake.

For example: the solution that receives data and carry out physical layer as UE is in harmonious proportion decoding, if decode results mistake represents that UE passes through the demodulating data that this data can not be correct, UE can carry out buffer memory by the soft Bit data of the incorrect decoding of this demodulation.When UE receives that base station sends to the data of UE for the second time, UE will merge processing with the soft Bit data of the demodulation coding out of demodulation for the second time for the first time.The mode merging depends on the send mode of the concrete HARQ of use.When for the first time with send for the second time be identical data time, UE side can be used the mode merging based on Chase to merge; When for the first time with send for the second time be the different coding version of identical data time, in UE side, use the mode of steadily increase redundancy to merge decoding.Chase merges and the mode of steadily increase redundancy merging decoding belongs to prior art well known by persons skilled in the art, does not do here further and describes.

Mode two: the information bit before encoding to each in base station is N _pdoubly repeat.

For example: the information bit before coding is b1, b2 ..., bM, is N by the mode of method two _pduring the repetition of=4 times, by the data bit obtaining after following repetition:

b1b1b1b1，b2b2b2b2，...，bMbMbMbM

Or the data bit of base station after to whole coding is N _pdoubly repeat.

Be N with information bit _pthe mode doubly repeating is similar, is not just that information bit is operated here, but the data bit after coding is done to N _poperation.

Or the symbol after modulate all constellations base station is N _pdoubly repeat.

For example: the symbol table that data are carried out after constellation modulation is shown: d1, d2 ..., dN, carries out N _pthe operation of=4 times is as follows:

d1d1d1d1，d2d2d2d2，...，dNdNdNdN

Further, above-mentioned base station sends covering compensating parameter tool to UE and can be: base station is sent to UE by this repetition factor, repeats, and then obtain separating the data after repetition so that this UE carries out corresponding solution according to this repetition factor.

Mode three: base station is carried out N by frequency expansion sequence to the symbol after modulating _pdirect sequence spread spectrum doubly.

For example: the symbol table that data are carried out after constellation modulation is shown: d1, d2 ...., dN, using length is 4 frequency expansion sequence hs=[+1 ,-1 ,+1 ,-1] carry out N _pthe operation of=4 times is as follows:

d1、-d1、d1、-d1，d2、-d2、d2、-d2，...，dN、-dN、dN、-dN

Above-mentioned modulation can be the modulation of being undertaken by planisphere, for example QPSK (Quaternary Phase Shift Keying quaternary PSK) modulation, 16QAM (Quadrature Amplitude Modulation, quadrature amplitude modulation) modulation, 64QAM modulation, 256QAM modulation etc., the present invention is not construed as limiting this.

It should be noted that, because above-mentioned mode one will realize the correct transmission of a packet, need re-transmission repeatedly, and the time that retransmits uplink and downlink round trip is at least 8ms at every turn, 4 times retransmit the time delay of bringing is 32ms, 8 times retransmit the time delay of bringing is 64ms, so it is only applicable to customer service as insensitive in time delays such as web page browsing, file transfer; And as long as aforesaid way two and mode three have been carried out suitable covering compensation, only need once to transmit the object that just can reach correct transmission, therefore be both applicable to the insensitive customer service of time delay, also be applicable to as the customer service of the delay sensitives such as VOIP (Voice over Internet Protocol, voice over internet protocol) business, game.

Further, above-mentioned base station sends covering compensating parameter tool to UE: base station is sent to UE by the parameter of this spreading factor and generation frequency expansion sequence necessity, so that this UE separates spread spectrum accordingly according to the parameter of this spreading factor and generation frequency expansion sequence necessity, and then obtains separating the data after spread spectrum.

In addition, above-mentioned physical layer signaling comprises DCI (Downlink Control Infornation, Downlink Control Information) signaling.

Alternatively, base station can send this covering compensating parameter to UE by specific information bit territory in multiplexing existing DCI signaling; Also can in DCI signaling, increase new DCI territory and send this covering compensating parameter to UE; Can also to UE, send this covering compensating parameter by special physical layer channel, this special physical layer channel can be multiplexing existing physical layer channel, or the physical layer channel newly increasing.The present invention is not construed as limiting this.

Above-mentioned high-level signaling comprises RRC (Radio Resource Control, Radio Resource is controlled) signaling.

Alternatively, base station can send this covering compensating parameter to UE by direct or indirect mode, and direct mode directly sends the numerical value of this covering compensating parameter to UE, and indirect mode sends the numerical value after quantizing to UE.

For example, if cover compensating parameter, be (2 ¹, 2 ², 2 ³, 2 ⁴) in any, direct mode is will (2 with 4 bits ¹, 2 ², 2 ³, 2 ⁴) in any be sent to UE, indirect mode will (2 ¹, 2 ², 2 ³, 2 ⁴) with 2 bits, to carry out coded quantization be (2,4,8,16), 2 corresponding bits are respectively (00,01,10,11), and any in (00,01,10,11) is sent to UE, because only needing 2 bits, indirect mode just can be sent to UE by covering compensating parameter, and direct mode may take more bit, therefore adopt indirect mode can significantly reduce the expense of signaling, for use physical layer channel, send this covering compensating parameter all the more so.

The combination of above-mentioned physical layer signaling and high-level signaling comprises the combination of using DCI signaling and RRC signaling.

For example, system can be chosen a kind of simultaneously from the extended method of repetition or spread spectrum, by DCI signaling, only by a few bits, indicates repetition or spreading factor (N _p), and then by a few bits, indicate the RRC signaling of selecting which kind of type.As above in example, can indicate N by the DCI signaling of 2 bits _pfor which value in (2,4,8,16), and then indicate and used which kind of RRC signaling with 2 bits.As:

Generate the parameter of frequency expansion sequence necessity, comprise the generation parameter of Spread Spectrum Sequence Set, and the frequency expansion sequence concentrated row or column of the frequency expansion sequence using for generating.

Further, at this UE, according to this covering compensating parameter, the data that receive are carried out after demodulation, if this base station receives the ACK of this UE feedback, this base station is calculated covering compensating factor again, and the covering compensating factor again calculating according to this obtains covering compensating parameter again, and the covering compensating parameter again obtaining according to this is carried out this covering compensation process, like this, because the lower grade of MCS, the service efficiency of channel is lower, therefore, again the covering compensating parameter obtaining can be when guaranteeing enough descending coverings, improve the grade of MCS, thereby improve the service efficiency of transmission channel.

If this base station receives the NACK of this UE feedback, by adjusting this preset value, adjust this covering compensating factor, thereby make UE carry out correct demodulation to the data that receive.

It should be noted that, the parameter of above-mentioned HARQ maximum retransmission, repetition factor, spreading factor and generation frequency expansion sequence necessity is above-mentioned covering compensating parameter.

Adopt such scheme, the enhancing that base station can cover covering limited users by covering compensating parameter, covers not enough problem thereby solved cell downlink.

Preferably, the embodiment of the present invention provides a kind of method that cell downlink covers of improving, and as shown in Figure 2, the method comprises:

The UE that downlink user is limited is determined in S201, base station.

Alternatively, after the data that send in this base station of UE demodulation, this base station receives the NACK of this UE feedback, and when the MCS that is defined as this UE distribution is the lowest class, determines that the descending covering of this UE is limited.The limited UE of descending covering is exactly the elementary UE of MCS.

Particularly, because the lower grade of MCS, corresponding spectrum efficiency is lower, and the SINR of work is just lower, and the downlink transfer distance that base station can be supported is far away, therefore, when base station is defined as MCS that this UE distributes and is the lowest class, represent that the downlink transfer distance that can support base station has reached maximum distance, if now base station still receives the NACK of this UE feedback, represent that this maximum distance also cannot guarantee that UE carries out correct demodulation, determine that the descending covering of this UE is limited.

S202, base station obtain from this base station to the descending circuit loss value of UE.

Wherein, P _lfor this descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, P _r=SNR+N, wherein, P _rfor the received power value of this UE in downlink traffic channel, SNR is signal to noise ratio corresponding to this CQI value, the noise power that N is each carrier wave.

Wherein, P _lfor this descending circuit loss value, P _sfor the performance number that this downlink reference signal is launched in base station, P _rSRPthis reference signal power value for this UE reception

P _L＝P _S-P _RSRP＝40-(-100)＝140dB。

Be that calculating in method two also can be carried out in UE side, at UE, calculate descending circuit loss value P _l=P _s-P _rSRPafter=40-(100)=140dB, this UE is by the P calculating _lvalue sends to base station by upstream message.

It should be noted that, aforesaid way one need to suppose that UE is only subject to the interference of AWGN, and be not subject to the interference of other homogenous frequency signals, and be not subject to the interference of other homogenous frequency signals, therefore result of calculation is a perfect condition value, and under the scene of frequently disturbing at multiple sectors at same, error is larger, therefore, in actual applications, preferably adopt mode two or mode three to obtain descending circuit loss value.

Formula is passed through according to this descending circuit loss value in S203, base station: N _s=R _s+ P _l-P _s+ Δ, calculates this covering compensating factor.

For example,, in LTE system, if R _sfor-100dBm, P _lfor 160dB, P _sfor 40dBm, according to above-mentioned formula: N _s=R _s+ P _l-P _s+ Δ, can obtain N _s=10+ Δ, that is to say, N _s>=10dB, but in order to improve the service efficiency of transmission channel, introduce a preset value Δ, this preset value Δ can arrange according to practical application or empirical value, and its effect is under wireless channel conditions, gives the blanketing fctor N that needs compensation _swhen reality is used, provide certain protection to measure in advance, to this preset value Δ, the present invention is not construed as limiting, and like this, adjusts preset value Δ can, when guaranteeing enough descending coverings, improve the service efficiency of transmission channel by base station.

S204, base station judge that whether non-this covering compensating factor is negative.

If the determination result is YES, perform step S205 to step S208.

If the determination result is NO, return to step S201.

S205, base station obtain covering compensating parameter according to covering compensating factor.

This step can comprise following three kinds of modes:

Mode one: base station covers compensating parameter according to this and adjusts HARQ maximum retransmission.

Mode two: formula is passed through in base station

calculate repetition factor.

Wherein, N _pfor repetition factor, N _sfor covering compensating factor.

Mode three: formula is passed through in base station:

calculate spreading factor.

Wherein, N _pfor spreading factor, N _sfor covering compensating parameter; This frequency expansion sequence is the concentrated a row or column of arbitrary frequency expansion sequence.

For example, N _p=4 o'clock, Spread Spectrum Sequence Set can be that following length is 4 matrix H:

H = [\begin{matrix} + 1 & + 1 & + 1 & + 1 \\ + 1 & - 1 & + 1 & - 1 \\ + 1 & + 1 & - 1 & - 1 \\ + 1 & - 1 & - 1 & + 1 \end{matrix}]

x_{q} (m) = e^{- j \frac{πqm (m + 1)}{N_{p}}}, 0 \leq m \leq N_{p} - 1

Covering compensation process is carried out according to covering compensating parameter in S206, base station.

b1b1b1b1，b2b2b2b2，...，bMbMbMbM

Or the data bit of base station after to whole coding is N _pdoubly repeat.

d1d1d1d1，d2d2d2d2，...，dNdNdNdN

For example: the symbol table that data are carried out after constellation modulation is shown: d1, d2 ..., dN, using length is 4 frequency expansion sequence hs=[+1 ,-1 ,+1 ,-1] carry out N _pthe operation of=4 times is as follows:

d1、-d1、d1、-d1，d2、-d2、d2、-d2，...，dN、-dN、dN、-dN

Above-mentioned modulation can be the modulation of being undertaken by planisphere, for example QPSK modulation, and 16QAM modulation, 64QAM modulation, 256QAM modulation etc., the present invention is not construed as limiting this.

It should be noted that, because above-mentioned mode one will realize the correct transmission of a packet, need re-transmission repeatedly, and the time that retransmits uplink and downlink round trip is at least 8ms at every turn, 4 times retransmit the time delay of bringing is 32ms, 8 times retransmit the time delay of bringing is 64ms, so it is only applicable to customer service as insensitive in time delays such as web page browsing, file transfer; And as long as aforesaid way two and mode three have been carried out suitable covering compensation, only need once to transmit the object that just can reach correct transmission, therefore be both applicable to the insensitive customer service of time delay, be also applicable to as the customer service of the delay sensitives such as VOIP business, game.

S207, base station, by the combination of physical layer signaling or high-level signaling or this physical layer signaling and this high-level signaling, send this covering compensating parameter to this UE.

Corresponding step S206, base station sends covering compensating parameter to UE and comprises following three kinds of modes:

Mode one, base station sends HARQ maximum retransmission to this UE, so that this UE, before HARQ number of retransmissions reaches HARQ maximum retransmission, carries out buffer memory or merging by the data of demodulation mistake.

For example: when UE receives data and carries out the solution mediation decoding of physical layer, if decode results mistake, represent that UE passes through this obstructed demodulating data that enough can be correct of data, UE can carry out buffer memory by the soft Bit data of the incorrect decoding of this demodulation.When UE receives that base station sends to the data of UE for the second time, UE will merge processing with the soft Bit data of the demodulation coding out of demodulation for the second time for the first time.The mode merging depends on the sending method mode of the concrete HARQ of use.When for the first time with send for the second time be identical data time, UE side can be used the mode merging based on Chase to merge; When for the first time with send for the second time be the different coding version of identical data time, in UE side, use the mode of steadily increase redundancy to merge decoding.Chase merges and the mode of steadily increase redundancy merging decoding belongs to prior art well known by persons skilled in the art, does not do here further and describes.

Mode two, base station is sent to UE by repetition factor, repeats, and then obtain separating the data after repeating so that this UE carries out corresponding solution according to this repetition factor.

Mode three, base station is sent to UE by the parameter of this spreading factor and generation frequency expansion sequence necessity, so that this UE separates spread spectrum accordingly according to the parameter of this spreading factor and generation frequency expansion sequence necessity, and then obtains separating the data after spread spectrum.

Wherein, above-mentioned physical layer signaling comprises DCI signaling.

Particularly, base station can send this covering compensating parameter to UE by specific information bit territory in multiplexing existing DCI signaling; Also can in DCI signaling, increase new DCI territory and send this covering compensating parameter to UE; Can also to UE, send this covering compensating parameter by special physical layer channel, this special physical layer channel can be multiplexing existing physical layer channel, or the physical layer channel newly increasing.The present invention is not construed as limiting this.

Above-mentioned high-level signaling comprises RRC signaling.

Particularly, base station can send this covering compensating parameter to UE by direct or indirect mode, and direct mode directly sends the numerical value of this covering compensating parameter to UE, and indirect mode sends the numerical value after quantizing to UE.

For example, if cover compensating parameter, be (2 ¹, 2 ², 2 ³, 2 ⁴) in any, direct mode is will (2 with 4 bits ¹, 2 ², 2 ³, 2 ⁴) in any be sent to UE, indirect mode will (2 ¹, 2 ², 2 ³, 2 ⁴) with 2 bits, to carry out coded quantization be (2,4,8,16), 2 corresponding bits are respectively (00,01,10,11), and any in (00,01,10,11) is sent to UE, because only needing 2 bits, indirect mode just can be sent to UE by covering compensating parameter, and direct mode may take more bit, therefore adopt indirect mode can significantly reduce the expense of signaling, for use physical layer channel, send this covering compensating parameter all the more so.。

S208, this UE carry out demodulation according to this covering compensating parameter to the data that receive.

Further, at this UE, according to this covering compensating parameter, the data that receive are carried out after demodulation, if this base station receives the ACK of this UE feedback, return to step S202 and again calculate covering compensating factor, and the covering compensating factor again calculating according to this obtains covering compensating parameter again, and the covering compensating parameter again obtaining according to this is carried out this covering compensation process, like this, because the lower grade of MCS, the service efficiency of channel is lower, therefore, again the covering compensating parameter obtaining can be when guaranteeing enough descending coverings, improve the grade of MCS, thereby improve the service efficiency of transmission channel.

It should be noted that, for above-mentioned embodiment of the method, for simple description, thus it is all expressed as to a series of combination of actions, but those skilled in the art should know, the present invention is not subject to the restriction of described sequence of movement.Secondly, those skilled in the art also should know, the embodiment described in specification all belongs to preferred embodiment, and related action and module might not be that the present invention is necessary.

The embodiment of the present invention provides a kind of base station 300, as shown in Figure 3, comprising:

Processing unit 301, for determining the limited UE of descending covering, obtains from this base station to the descending circuit loss value of this UE, and obtains covering compensating parameter according to described descending circuit loss value, and carries out and cover compensation process according to described covering compensating parameter;

Transmitting element 302, for by the combination of physical layer signaling or high-level signaling or described physical layer signaling and described high-level signaling, sends described covering compensating parameter to described UE, so that described UE carries out demodulation according to described covering compensating parameter to the data that receive.

Wherein, this physical layer signaling comprises DCI signaling.

This high-level signaling comprises RRC signaling.

The combination of this physical layer signaling and high-level signaling comprises the combination of using DCI signaling and RRC signaling.

Further, as shown in Figure 4, this base station also comprises: receiving element 303, after the data that send in this base station of this UE demodulation, receives the NACK of this UE feedback;

This processing unit 301 specifically for, at this receiving element 303, receive after this NACK, and this processing unit 301 is when being defined as MCS that this UE distributes and being the lowest class, determines that the descending covering of this UE is limited.

Alternatively, the CQI value that this receiving element 303 sends specifically for receiving this UE;

This processing unit 301, specifically for receiving after this CQI value at this receiving element 303, passes through formula according to this CQI value: P _l=P _s-P _r, calculate this descending circuit loss value; Wherein, P _lfor this descending circuit loss value, P _sfor the transmission power level of base station down, P _r=SNR+N, wherein, P _rfor the received power value of this UE in downlink traffic channel, SNR is signal to noise ratio corresponding to this CQI value, the noise power that N is each carrier wave.

Alternatively, the reference signal power value that this receiving element 303 reports specifically for receiving UE measurement;

This processing unit 301, specifically for receiving after this reference signal power value at this receiving element 303, passes through formula according to the performance number of this reference signal: P _l=P _s-P _rSRP, calculate this descending circuit loss value.

Wherein, P _lfor this descending circuit loss value, P _sfor the performance number that this downlink reference signal is launched in base station, P _rSRPthis reference signal power value of reception for this UE.

P _L＝P _S-P _RSRP＝40-(-100)＝140dB。

Alternatively, this receiving element 303 is specifically for receiving the descending circuit loss value reporting after this UE measures.

Further, this processing unit 301 is specifically for passing through formula: N _s=R _s+ P _l-P _s+ Δ, calculates and covers compensating factor, and obtain covering compensating parameter according to this covering compensating factor; Wherein, N _sfor this covers compensating factor, unit is dB, P _lfor this descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, R _sthe MCS using in Traffic Channel for this UE is the receiving sensitivity under the lowest class, and Δ is preset value, is nonnegative real number.

Further, this processing unit 301, also for when definite this covering compensating factor is negative, returns to the step that re-executes the UE that determines that descending covering is limited.

Alternatively, this processing unit 301 is adjusted mixed automatic retransfer request HARQ maximum retransmission specifically for cover compensating parameter according to this, and utilizes the HARQ maximum retransmission after described adjustment to upgrade former HARQ maximum retransmission.

This transmitting element is sent to this UE by this covering compensating parameter and specifically comprises: to this UE, send this HARQ maximum retransmission, so that this UE, before HARQ number of retransmissions reaches HARQ maximum retransmission, carries out buffer memory or merging by the data of demodulation mistake.

For example, when UE receives data and carries out the solution mediation decoding of physical layer, if decode results mistake, represents that UE passes through this obstructed demodulating data that enough can be correct of data, UE can carry out buffer memory by the soft Bit data of the incorrect decoding of this demodulation.When UE receives that base station sends to the data of UE for the second time, UE will merge processing with the soft Bit data of the demodulation coding out of demodulation for the second time for the first time.The mode merging depends on the send mode of the concrete HARQ of use.When for the first time with send for the second time be identical data time, UE side can be used the mode merging based on Chase to merge; When for the first time with send for the second time be the different coding version of identical data time, in UE side, use the mode of steadily increase redundancy to merge decoding.Chase merges and the mode of steadily increase redundancy merging decoding belongs to prior art well known by persons skilled in the art, does not do here further and describes.

Alternatively, this processing unit 301 is specifically for passing through formula:

calculate repetition factor, wherein, N _pfor this repetition factor, N _sfor this covers compensating factor.

This processing unit 301 is concrete also for the information bit before each coding is done to N _pdoubly repeat.

b1b1b1b1，b2b2b2b2，...，bMbMbMbM

Or, the data bit after whole coding is done to N _pdoubly repeat.

Be N with information bit _pthe mode doubly repeating is similar, is not just that information bit is operated here, but the coded-bit after coding is done to N _poperation.

Or, the symbol after all modulation is done to N _pdoubly repeat.

For example: the symbol table that data are carried out after constellation modulation is shown: d1, d2 ..., dN, carries out N _pthe operation of=4 times of weights is as follows:

d1d1d1d1，d2d2d2d2，...，dNdNdNdN

This transmitting element is sent to UE by this covering compensating parameter and specifically comprises: this transmitting element is sent to this UE by this repetition factor, so that this UE carries out corresponding solution according to this repetition factor, repeats.

calculate spreading factor, wherein, N _pfor this spreading factor, N _sfor this covers compensating factor, and by frequency expansion sequence, the symbol after modulating is carried out to N _pdirect sequence spread spectrum doubly; This frequency expansion sequence is the concentrated a row or column of arbitrary frequency expansion sequence.

H = [\begin{matrix} + 1 & + 1 & + 1 & + 1 \\ + 1 & - 1 & + 1 & - 1 \\ + 1 & + 1 & - 1 & - 1 \\ + 1 & - 1 & - 1 & + 1 \end{matrix}]

x_{q} (m) = e^{- j \frac{πqm (m + 1)}{N_{p}}}, 0 \leq m \leq N_{p} - 1

d1、-d1、d1、-d1，d2、-d2、d2、-d2，...，dN、-dN、dN、-dN

This transmitting element is sent to UE by this covering compensating parameter and specifically comprises: the parameter information of this spreading factor and this frequency expansion sequence is sent to this UE, so that this UE separates spread spectrum accordingly according to the parameter information of this spreading factor and this frequency expansion sequence.

In addition, this receiving element 303, also for the data that receive being carried out after demodulation according to this covering compensating parameter at this UE, receives ACK or the NACK of this UE feedback;

If this processing unit 301 also receives the ACK of this UE feedback for this receiving element 303, again calculate and cover compensating factor, and the covering compensating factor again calculating according to this obtains covering compensating parameter again, and the covering compensating parameter again obtaining according to this is carried out this covering compensation process; If this receiving element 303 receives the NACK of this UE feedback, by adjusting this preset value, adjust this covering compensating factor.

Adopt above-mentioned base station, the enhancing that base station can cover covering limited users by covering compensating parameter, covers not enough problem thereby solved cell downlink.

Affiliated those skilled in the art can be well understood to, and for convenience and simplicity of description, the specific works process of the base station of foregoing description, can, with reference to the corresponding process in preceding method embodiment, not repeat them here.

The embodiment of the present invention provides a kind of communication system, and as shown in Figure 5, this communication system comprises: base station 300 and UE500 that above-described embodiment is described,

The covering compensating parameter that this UE sends for receiving base station 300, and the data of reception are carried out to demodulation according to this coverings compensating parameter, and to base station 300 feeding back ACKs or NACK.

Above-mentioned base station applies improves in above-mentioned the method that cell downlink covers, and the unit in this base station is also corresponding with each step in the method.

It should be noted that, this communication system can be GSM (Global System for Mobile communications, global system for mobile communications), CDMA (Code Division Multiple Access, code division multiple access) system, TDMA (Time Division Multiple Access, time division multiple access) system, WCDMA (Wideband Code Division Multiple Access Wireless, Wideband Code Division Multiple Access (WCDMA)), FDMA (Frequency Division Multiple Addressing, frequency division multiple access) system, OFDMA (Orthogonal Frequency-Division Multiple Access, OFDM) system, Single Carrier Frequency Division Multiple Access (SC-FDMA) system, GPRS (General Packet Radio Service, GPRS) system, LTE (Long Term Evolution, Long Term Evolution) system, and other these type of communication systems.

Adopt above-mentioned communication system, the enhancing that base station can cover covering limited users by covering compensating parameter, covers not enough problem thereby solved cell downlink

One of ordinary skill in the art will appreciate that: all or part of step that realizes said method embodiment can complete by the relevant hardware of program command, aforesaid program can be stored in a computer read/write memory medium, this program, when carrying out, is carried out the step that comprises said method embodiment; And aforesaid storage medium comprises: various media that can be program code stored such as ROM, RAM, magnetic disc or CDs.

The above; be only the specific embodiment of the present invention, but protection scope of the present invention is not limited to this, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; can expect easily changing or replacing, within all should being encompassed in protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of described claim.

Claims

1. improve the method that cell downlink covers, it is characterized in that, comprising:

2. method according to claim 1, is characterized in that, described physical layer signaling comprises Downlink Control Information DCI signaling;

Described high-level signaling comprises radio resource control RRC signaling;

3. method according to claim 1 and 2, is characterized in that, the UE that descending covering is limited is determined in described base station, specifically comprises:

4. according to the method described in claims 1 to 3 any one, it is characterized in that, described base station obtains from described base station to the descending circuit loss value of described UE, specifically comprises:

5. according to the method described in claim 1 to 4 any one, it is characterized in that, describedly according to described descending circuit loss value, obtain covering compensating parameter, specifically comprise:

6. method according to claim 5, is characterized in that, also comprises: when definite described covering compensating factor is negative, returns and re-execute the described step of determining the UE that descending covering is limited.

7. according to the method described in claim 5 or 6, it is characterized in that, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: according to described covering compensating factor, adjust mixed automatic retransfer request HARQ maximum retransmission;

8. according to the method described in claim 5 or 6, it is characterized in that, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: pass through formula:

calculate repetition factor, wherein, N _pfor described repetition factor, N _sfor described covering compensating factor;

Information bit before each coding is done to N _pdoubly repeat; Or,

Data bit after whole coding is done to N _pdoubly repeat; Or,

Symbol after all modulation is done to N _pdoubly repeat.

9. according to the method described in claim 5 or 6, it is characterized in that, describedly according to described covering compensating factor, obtain covering compensating parameter, comprising: pass through formula:

10. according to the method described in claim 5 to 9 any one, it is characterized in that, at described UE, according to described covering compensating parameter, the data that receive carried out, after demodulation, also comprising:

11. according to the method described in claim 1 to 10 any one, it is characterized in that, described covering compensating parameter comprises: HARQ maximum retransmission or repetition factor or spreading factor and the parameter that generates frequency expansion sequence necessity.

12. 1 kinds of base stations, is characterized in that, comprising:

13. base stations according to claim 12, is characterized in that, described physical layer signaling comprises Downlink Control Information DCI signaling;

Described high-level signaling comprises radio resource control RRC signaling;

14. according to the base station described in claim 12 or 13, it is characterized in that, also comprises:

Receiving element, for receiving the NACK of described UE feedback;

Described processing unit specifically for, at described receiving element, receive after described NACK, and when being defined as modulation that described UE distributes and encoding scheme MCS and being the lowest class, determine that the descending covering of described UE is limited.

15. according to claim 12 to the base station described in 14 any one, it is characterized in that the channel quality indicator (CQI) value that described receiving element sends specifically for receiving described UE;

16. according to claim 12 to the base station described in 15 any one, it is characterized in that, described processing unit is specifically for passing through formula: N _s=R _s+ P _l-P _s+ Δ, calculates and covers compensating factor, and obtain covering compensating parameter according to described covering compensating factor; Wherein, N _sfor described covering compensating factor, P _lfor described descending circuit loss value, P _sfor the transmission power level of base station in downlink traffic channel, R _sthe MCS using in Traffic Channel for described UE is the receiving sensitivity under the lowest class, and Δ is preset value, is nonnegative real number.

17. base stations according to claim 16, is characterized in that, described processing unit, also for when definite described covering compensating factor is negative, returns and re-executes the described step of determining the UE that descending covering is limited.

18. according to the base station described in claim 16 or 17, it is characterized in that, described processing unit is specifically for adjusting HARQ maximum retransmission according to described covering compensating parameter, and utilizes the HARQ maximum retransmission after described adjustment to upgrade former HARQ maximum retransmission.

19. according to the base station described in claim 16 or 17, it is characterized in that, described processing unit is specifically for passing through formula: calculate repetition factor, wherein, N _pfor described repetition factor, N _sfor described covering compensating factor; Described processing unit is concrete also for the information bit before each coding is done to N _pdoubly repeat; Or, the data bit after whole coding is done to N _pdoubly repeat; Or, the symbol after all modulation is done to N _pdoubly repeat.

20. according to the base station described in claim 16 or 17, it is characterized in that, described processing unit is specifically for passing through formula:

21. according to claim 16 to the base station described in 20 any one, it is characterized in that, described receiving element, also for the data that receive being carried out after demodulation according to described covering compensating parameter at described UE, receives ACK or the NACK of described UE feedback;

22. according to claim 12 to the base station described in 21 any one, it is characterized in that, described covering compensating parameter comprises: HARQ maximum retransmission or repetition factor or spreading factor and the parameter that generates frequency expansion sequence necessity.

23. 1 kinds of communication systems, is characterized in that, comprising: base station and terminal,

Described base station is the base station described in claim 12 to 22 any one;