CN102036301B - Method and device for transmitting downlink demodulation reference signals of relay link and relay system - Google Patents

Abstract

The invention discloses a method and device for transmitting downlink demodulation reference signals of a relay link and a relay system. The method is used for mapping the demodulation reference signals to a time-frequency two-dimensional resource, wherein the demodulation reference signals are non-precoding reference signals and used for carrying out coherent demodulation to the downlink data transmission of the relay link. The invention solves the problem on the transmission of the demodulation reference signals of the relay link, ensures the reliability of the data transmission of the relay link, has no influence on a terminal in the same cell, and simultaneously reduces the expenses of the demodulation reference signals and the complexity of design.

Description

The transmission method of downlink demodulation reference signals of relay link, device and relay system

Technical field

The present invention relates to wireless communication field, in particular to transmission method, device and the relay system of a kind of downlink demodulation reference signals of relay link (Demodulation Reference Signal is called for short DMRS).

Background technology

At present, the demand for development of mobile communication to support higher transmission rate, more perfect quorum sensing inhibitor and higher resource utilization.In order to reach the requirement of high transfer rate, next generation mobile communication system will adopt higher frequency bandwidth transmission signals, and higher frequency bandwidth will bring larger path loss simultaneously, affects the network coverage.Relaying (Relay) technology can not only increase covering and balances and increase cell throughout, and, via node (Relay Node, be called for short RN) compared to base station, there is relatively little deployment cost, therefore, relaying technique is regarded as 3GPP (the 3rd Generation Partnership Project, be called for short 3GPP) Long Term Evolution (Long Term Evolution, be called for short LTE) evolution technology-senior Long Term Evolution (LTE-Advanced, be called for short LTE-A) system in a key technology.

LTE/LTE-A system is with based on OFDM (Orthogonal FrequencyDivision Multiplexing, referred to as OFDM) technology.In an ofdm system, when the communication resource is-form of frequently bidimensional.Such as, in LTE system, the communication resource is all that each radio frames (radioframe) length is 10ms with frame (frame) for unit divides on time orientation, comprise the subframe (sub-frame) that 10 length are 1ms, as shown in Figure 1.According to the difference of Cyclic Prefix (Cyclic Prefix, referred to as CP) length, each subframe can comprise 12 or 14 OFDM symbol.In frequency direction, resource with subcarrier (sub-carrier) for unit divide, specifically in the communications, the least unit of Resourse Distribute is Resource Block (Resource Block, referred to as RB), a Physical Resource Block (Physical RB, referred to as PRB) of corresponding physical resource.A PRB comprises 12 subcarriers at frequency domain.In each OFDM symbol, the resource of a corresponding subcarrier is called resource element (Resource Element is called for short RE).

After introducing relay station, be equivalent to the many jumpings of the transmission of data, for double bounce system, the communication pattern of base station-terminal originally becomes the communication pattern of base station-relay station-terminal, wherein base station-relay station link is called as repeated link (backhaul link), relay station-terminal link is called as access link (access link), and base station-terminal link is called as the link that direct transfers (direct link).In multihop system, under a part of terminal is linked into relay station, complete communication service by relay station.After introducing relay station; need to ensure the backwards compatibility for terminal; namely terminal (the such as LTE Release-8 of version before ensureing; be called for short Rel-8) also can be linked into relay station under; at this time just need under the prerequisite not affecting the communication of relay station subordinate terminal, mark off a part of resource to guarantee the communication between base station and relay station.

For lte-a system, determine in current lte-a system that base station-relay station communication communicates with relay station-terminal to carry out in a time division manner, concrete, in descending sub frame, mark off a part for base station-relay station communication, these subframes are called as relaying (Relay) subframe.For the Rel-8 terminal of relay station subordinate, Relay subframe is indicated as MBSFN (Multicast Broadcast Single Frequency Network, Multicast Broadcast Single Frequency Network, referred to as MBSFN) subframe, thus Rel-8 terminal can skip these subframes, while completing base station-relay station communication, ensure that the backwards compatibility for Rel-8 terminal.In lte-a system, the structure of Relay subframe as shown in Figure 2.

In Relay subframe, RN sends control information to subordinate terminal in front 1 or 2 OFDM symbol, pass through the switching interval from the state of transmission to the switching of accepting state afterwards, downlink data of relay link information is received from base station, and then through the conversion interval from accepting state to the switching of the state of transmission.The efficient resource being only concerned about that in Relay subframe, base station is transmitted to relay station in the present invention.In Relay subframe, the Traffic Channel of base station to relay station (Relay-Physical Downlink Shared Channel will be comprised, be called for short R-PDSCH), control channel (Relay-Physical Downlink Control Channel, be called for short R-PDCCH) and possible broadcast channel (Relay-Physical BroadcastChannel is called for short R-PBCH) etc.The transmitting of above-mentioned channel, all will based on the support of corresponding demodulated reference signal.

In lte-a system, consider the feature of the channel that relay link downlink transmits and resource structures, the sending method of corresponding DMRS will be different from the link that direct transfers.Relay link downlink control data, such as relaying Physical Downlink Control Channel (R-PDCCH) etc., and the data in repeated link Physical Broadcast Channel (R-PBCH), may be community specific (cell-specific) for relay station, cannot carry out precoding transmissions, the precoding DMRS so discussed in LTE-A now will not be suitable for the demodulation of these channels.

Meanwhile, because the expense of the public reference signal (cell-specific referencesignal is called for short CRS) of LTE system is larger, and efficiency comparison is low, therefore can support to use MBSFN sub-frame transmission unicast service in lte-a system.Because the multicast domain of MBSFN sub-frame does not exist CRS, if base station uses MBSFN sub-frame to transmit data to relay station, so under current technology, relay station will not have operable reference signal to carry out data demodulates.

On the other hand, in lte-a system, the antenna port number of base station may reach 8.When adopting transmit diversity mode to transmit data, diversity gain can't have clear improvement along with the increase of diversity order, but because diversity order is corresponding with corresponding reference signal port, namely diversity order increase can cause the port number of corresponding DMRS to increase, and the expense of reference signal and the complexity of design also will be caused to increase.This is also a problem needing to solve at repeated link.Meanwhile, under transmit diversity transmission mode, receiving terminal needs the emission port number knowing demodulated reference signal, to determine that corresponding reference signal pattern carries out data demodulates.

Improve the reliability of transfer of data compared to diversity transmission, multiplexing transmission then can improve power system capacity.Under space division multiplexing transmission mode, be the equal of the data of the multiple layer of multiplexing transmission (layer) on identical running time-frequency resource, the data of multiple layers carried out the process of precoding before mapping.Specifically multiplexing number of layers is determined according to the order (rank) of multiple-input and multiple-output (Multi-InputMulti-Output, referred to as MIMO) channel.

At present in the discussion of 3GPP LTE-A correlation technique, the discussion of relay link downlink DMRS and associated problem does not also launch, and not yet proposes effective solution.

Summary of the invention

There is no the problem of the processing scheme of downlink demodulation reference signals of relay link in relevant discussion for 3GPP LTE-A and propose the present invention, for this reason, main purpose of the present invention is the transmission plan providing a kind of downlink demodulation reference signals of relay link, to solve the problem.

To achieve these goals, according to an aspect of the present invention, a kind of transmission method of downlink demodulation reference signals of relay link is provided.

Transmission method according to downlink demodulation reference signals of relay link of the present invention comprises: when demodulated reference signal is mapped in-and frequently in two-dimentional resource, wherein, demodulated reference signal is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission.

Preferably, downlink data of relay link comprise following one of at least: the data of relay link downlink control data, repeated link Physical Broadcast Channel and the data of repeated link Physical Downlink Shared Channel, wherein, relay link downlink control data comprise following one of at least: the data of repeated link Physical Downlink Control Channel, relay link downlink control format indication information, relay link downlink mixed automatic retransfer indication information.

Preferably, time-frequently two-dimentional resource comprise in frequency direction the Physical Resource Block that transmitting downlink data distributes.

Preferably, time-frequently two-dimentional resource comprise at time orientation the OFDM symbol carrying downlink data of relay link in a downlink relay sub-frame.

Wherein, according to the Physical Cell Identifier number sub-carrier positions that adjustment demodulated reference signal maps in Physical Resource Block.

Wherein, the OFDM symbol position that demodulated reference signal maps is fixed in Physical Resource Block.

Wherein, according to the OFDM symbol position that system bandwidth adjustment demodulated reference signal maps, or the OFDM symbol position that the difference adjustment demodulated reference signal of the OFDM symbol taken according to downlink data of relay link maps.

Preferably, the layer that demodulated reference signal and the port that downlink data of relay link transmits or downlink data of relay link transmit associates corresponding.

Preferably, under transmit diversity transmission mode, demodulated reference signal is corresponding with the port association that downlink data of relay link transmits, wherein, when downlink data of relay link transmits at the port that multiple downlink data of relay link transmits, the demodulated reference signal that association corresponds to different downlink data of relay link transmit port is mutually orthogonal.

Preferably, under space division multiplexing transmission mode, demodulated reference signal pattern associates corresponding with the number of layers that downlink data of relay link transmits, and when carrying out multilayer transmission, the demodulated reference signal that association corresponds to each layer is mutually orthogonal.

Wherein, orthogonal manner comprise following one of at least: time division multiplexing TDM, frequency division multiplex FDM, code division multiplex CDM.

To achieve these goals, according to another aspect of the present invention, a kind of processing method of downlink data of relay link is provided.

Processing method according to downlink data of relay link of the present invention comprises: the port number of downlink data of relay link transmission under setting diversity mode, when antenna for base station port number is greater than N, be set as N number of by the port number that downlink data of relay link transmits, N is less than or equal to 4.

Wherein, the mode of setting is: the transfer of data that to use in antenna port N number of in base station carries out under diversity transmission mode; Or base station adopts virtual-antenna port technique, data transmission port is mapped as N number of.

2,4, the port number of public reference signal CRS in present sub-frame wherein, the number of port of downlink data of relay link transmission comprises one of following:.

To achieve these goals, according to a further aspect of the invention, a kind of indicating means of demodulated reference signal port number is provided.

Indicating means according to demodulated reference signal port number of the present invention comprises: base station is to the port number of relay station instruction downlink demodulation reference signals of relay link, and indicating means is indirect indicating means and/or direct indicating means.

Wherein, indirect indicating means comprises one of following: the first mapping relations between the port number of demodulated reference signal and antenna for base station port number are set up in base station, and according to the port number of the first mapping relations instruction demodulated reference signal; The port number of CRC mask to relay station instruction demodulated reference signal of repeated link Physical Broadcast Channel is passed through in base station; The second mapping relations between the port number of demodulated reference signal and the port number of base station public reference signal are set up in base station, and indicate the port number of demodulated reference signal according to the second mapping relations.

Further, the port number of demodulated reference signal and the first mapping relations of antenna for base station port number are set up in base station, first mapping relations comprise one of following: when antenna for base station port number is 1, the port number of demodulated reference signal is 1, when antenna for base station port number is more than or equal to 2, the port number of demodulated reference signal is 2; Or when antenna for base station port number is 1 or 2, the port number of demodulated reference signal is 1 or 2, when antenna for base station port number is more than or equal to 4, the port number of demodulated reference signal is 4.

Preferably, after the second mapping relations between the port number of demodulated reference signal and the port number of base station public reference signal are set up in base station, method also comprises: relay station obtains base station public reference signal port number by the CRC mask of base station physical broadcast channel, is obtained the port number of demodulated reference signal by the second mapping relations; Mapping relations are, the port number of demodulated reference signal equals base station public reference signal port number.

Wherein, direct indicating means comprises: the port number of downlink demodulation reference signal is indicated by the indicating bit in relay link downlink control signal.

To achieve these goals, according to a further aspect of the invention, a kind of base station is provided.

Base station according to the present invention comprises: memory module, for storing the demodulated reference signal pattern from base-station transmission; Relating module, for associating according to the port number of transfer of data or number of layers the demodulated reference signal pattern stored in corresponding memory module; Mapping block, when demodulated reference signal is mapped in corresponding by the demodulated reference signal pattern for obtaining according to relating module-the two-dimentional resource of frequency; Sending module, for transmitting corresponding demodulated reference signal, wherein, demodulated reference signal is non-precoded reference signal, for carrying out coherent demodulation to downlink data of relay link.

Preferably, relating module comprises adjustment submodule, for adjusting demodulated reference signal pattern at time orientation and/or frequency direction.

Further, adjustment submodule also comprises, the first adjustment submodule, for the OFDM symbol position mapped according to system bandwidth adjustment demodulated reference signal; Or the OFDM symbol position that the difference adjustment demodulated reference signal of the OFDM symbol taken according to downlink data of relay link maps; Second adjustment submodule, for adjusting the sub-carrier positions that demodulated reference signal maps in Physical Resource Block according to Physical Cell Identifier number.

Preferably, base station also comprises processing module, and for setting the port number of downlink data of relay link transmission under diversity mode, when antenna for base station port number is greater than N, be set as N number of by the port number that downlink data of relay link transmits, N is less than or equal to 4.

Wherein, processing module determines N number of port as downlink data of relay link transmission in the antenna port of base station; Or adopt the mode of virtual port to be mapped as N number of by the port number that downlink data of relay link transmits.

Preferably, base station also comprises indication information generation module, for generating relay link downlink indication information, relay link downlink indication information is used for the port number that transmits to relay station instruction association corresponding to the downlink data of relay link of demodulated reference signal base station or number of layers.

Wherein, indication information generation module indicates one of in the following manner: relay link downlink indication information is the CRC mask of repeated link Physical Broadcast Channel, and the port number of demodulated reference signal is indicated by the CRC mask of repeated link Physical Broadcast Channel; Relay link downlink indication information is the indication information of antenna for base station port number, the first mapping relations between the port number of demodulated reference signal and antenna for base station port number are set up in base station, and indicate the port number of demodulated reference signal according to the first mapping relations; Indication information is the indication information of base station public reference signal port number, the second mapping relations between the port number of demodulated reference signal and base station public reference signal port number are set up in base station, and indicate the port number of demodulated reference signal according to the second mapping relations.

To achieve these goals, according to a further aspect of the invention, a kind of relay station is provided.

Relay station according to the present invention comprises: receiver module, and for receiving downlink demodulation reference signals of relay link, downlink demodulation reference signals of relay link is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission.

Preferably, relay station also comprises indication information receiver module, for receiving the relay link downlink indication information that indication information generation module generates, relay link downlink indication information is used for relay station and determines to associate the port number or number of layers that transmit corresponding to the downlink data of relay link of demodulated reference signal.

To achieve these goals, according to a further aspect of the invention, a kind of relay system is provided.

Relay system according to the present invention comprises: base station and relay station, wherein,

Base station comprises: memory module, for storing the demodulated reference signal pattern from base-station transmission; Relating module, for associating according to the port number of transfer of data or number of layers the demodulated reference signal pattern stored in corresponding memory module; Mapping block, when demodulated reference signal is mapped in corresponding by the demodulated reference signal pattern for obtaining according to relating module-the two-dimentional resource of frequency; Sending module, for transmitting corresponding demodulated reference signal, wherein, demodulated reference signal is non-precoded reference signal, for carrying out coherent demodulation to downlink data of relay link;

Relay station comprises: receiver module, and for receiving downlink demodulation reference signals of relay link, downlink demodulation reference signals of relay link is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission.

Pass through the present invention, when DMRS is mapped in-frequently bidimensional resource forms DMRS pattern, contain the instruction operation of DMRS port simultaneously, solve the transmission problem of downlink demodulation reference signals of relay link, ensure that the reliability that downlink data of relay link transmits, and can not the terminal in same community be had an impact.Meanwhile, adopt data mapping method when diversity transmission, namely set the port number of diversity transmission, under the prerequisite ensureing diversity transmission gain, reduce the expense of demodulated reference signal and the complexity of design.

Accompanying drawing explanation

Accompanying drawing described herein is used to provide a further understanding of the present invention, and form a application's part, schematic description and description of the present invention, for explaining the present invention, does not form inappropriate limitation of the present invention.In the accompanying drawings:

Fig. 1 is frame structure schematic diagram in the LTE/LTE-A system according to correlation technique;

Fig. 2 is the Relay subframe structure schematic diagram according to correlation technique;

Fig. 3 is the Optimizing Flow figure of the DMRS transmission method according to the embodiment of the present invention;

Fig. 4 is the DMRS pattern schematic diagram of example 1 of the present invention;

Fig. 5 is the DMRS pattern schematic diagram of example 1 of the present invention;

Fig. 6 is the DMRS pattern schematic diagram of example 1 of the present invention;

Fig. 7 is the DMRS pattern schematic diagram of example 2 of the present invention;

Fig. 8 is the DMRS pattern schematic diagram of example 2 of the present invention;

Fig. 9 is the DMRS pattern schematic diagram of example 2 of the present invention;

Figure 10 is the DMRS pattern schematic diagram of example 3 of the present invention;

Figure 11 is the DMRS pattern schematic diagram of example 3 of the present invention;

Figure 12 is the DMRS pattern schematic diagram of example 4 of the present invention;

Figure 13 is the DMRS pattern schematic diagram of example 5 of the present invention;

Figure 14 is the DMRS pattern schematic diagram of example 6 of the present invention;

Figure 15 is the DMRS pattern schematic diagram of example 7 of the present invention;

Figure 16 is the DMRS pattern schematic diagram of example 7 of the present invention;

Figure 17 is the structured flowchart of the base station according to the embodiment of the present invention;

Figure 18 is the preferred structure block diagram of the base station according to the embodiment of the present invention;

Figure 19 is the structured flowchart of the relay station according to the embodiment of the present invention;

Figure 20 is the structured flowchart of the relay system according to the embodiment of the present invention.

Embodiment

Functional overview

Embodiments provide the design of a kind of relay link downlink DMRS, when DMRS is mapped in-frequently in two-dimentional resource, DMRS port is indicated, solve the transmission problem of relay link downlink DMRS, ensure that the reliability that downlink data of relay link transmits, and can not the terminal in same community be had an impact.Provide the transmission method of downlink data of relay link during a kind of diversity transmission, the port number of setting diversity transmission, under the prerequisite ensureing diversity transmission gain, reduces the expense of demodulated reference signal and the complexity of design simultaneously.

Embodiment of the method

According to embodiments of the invention, provide a kind of transmission method of downlink demodulation reference signals of relay link, the method comprises when being mapped in by DMRS-the two-dimentional resource of frequency on, wherein, demodulated reference signal is non-precoded (non-precoded) reference signal, for the coherent demodulation of downlink data of relay link transmission.

Downlink data of relay link comprise following one of at least: the data of relay link downlink control data, repeated link Physical Broadcast Channel and the data of repeated link Physical Downlink Shared Channel.And relay link downlink control data comprise following one of at least: the data of repeated link Physical Downlink Control Channel or relay link downlink control format indication information or relay link downlink mixed automatic retransfer indication information etc.Relay link downlink business datum comprises the data transmitted in relay link downlink Physical Shared Channel, and its transmission mode can be transmit diversity or space division multiplexing.

The mapping position of DMRS comprises in frequency direction the Physical Resource Block that transmitting downlink data distributes; The mapping position of DMRS comprises the OFDM symbol of bearing downlink data in a downlink relay sub-frame at time orientation.Namely the DMRS described in the present invention is only arranged in the resource of scheduling.Such as, if this DMRS is used for the data demodulates of repeated link Physical Broadcast Channel, so this DMRS only can be mapped in the resource shared by R-PBCH transmission, such as, in some specific PRB; If this DMRS is used for the demodulation of repeated link control data, such as R-PDCCH, R-PCFICH, R-PHICH etc., so this DMRS only can be mapped in relay link downlink control domain, is such as the part OFDM symbol in some PRB or PRB; If this DMRS is used for the coherent demodulation of relay link downlink business data transmission, so this DMRS only can be mapped in the resource shared by respective data transfer.

Preferably, the OFDM symbol that DMRS maps does not comprise the OFDM symbol being mapped with public reference signal.

Fig. 3 is the Optimizing Flow figure of the DMRS processing method according to the embodiment of the present invention; As shown in Figure 3, the method comprises following step S302 to step S306:

Step S302, DMRS associate corresponding with the port that downlink data of relay link transmits or layer.

Under the transmission mode of transmit diversity, the DMRS that the present invention describes is corresponding with the antenna port of respective data transfer, and the DMRS of each port is mutually orthogonal.Here antenna port refers to the antenna port number that receiving terminal can be seen when receiving data, namely when not adopting virtual-antenna technology, antenna port number is exactly actual antenna port number, when adopt virtual-antenna technology, antenna port number be virtual after antenna port number.Under the transmission mode of space division multiplexing, the DMRS that the present invention describes is corresponding with the layer of respective data transfer, and the DMRS of each layer is mutually orthogonal.And in this case, while transfer of data is carried out in base station, need the index indicating corresponding precoding codebook or precoding codebook.The orthogonal manner of the DMRS of the multiport/multilayer of the present invention's statement can be one or several the combination in FDM, TDM, CDM.

Step S304, at time orientation and/or frequency direction adjustment DMRS pattern.

The pattern of the demodulated reference signal DMRS that the present invention describes can be fixed, and also can adjust flexibly.Adjustment comprises the adjustment of time orientation and the adjustment of frequency direction.The adjustment of time orientation refers to the OFDM symbol position changing DMRS mapping.Such as, in LTE system, the symbolic number that PDCCH takies when descending system bandwidth is greater than 10 RB and is less than or equal to 10 RB may be different, and this will cause the original position difference of the OFDM symbol of relay link downlink transmission in both cases.At this moment, the pattern of a kind of DMRS can be designed for different situations, with the situation of compatible different system bandwidth, or design the pattern of different DMRS for different system bandwidth situation, ensure the performance having a good channel estimating in varied situations.The adjustment of time orientation also can be take OFDM symbol difference for transfer of data to adjust.Such as, if DMRS is used for the data demodulates of R-PDCCH, the OFDM symbol number that the change due to control channel content causes R-PDCCH to take may also can change.At this moment, the pattern of a kind of DMRS can be designed for the situation of all permissions, or adjust the character position of DMRS mapping flexibly for different situations.The adjustment of frequency direction refers to the sub-carrier positions that change DMRS maps in a RB.Such as, the mapping subcarriers position of DMRS in RB can be fixed, also Physical Cell Identifier number (Physical Cell ID can be utilized like that by similar LTECRS, be called for short PCID) determine the mapping subcarriers position of DMRS in RB, like this when this DMRS is also transmitted in neighbor cell in this RB, the mutual interference of DMRS can be avoided.

It should be noted that step S304 is optional step, when the DMRS pattern that the present invention describes does not adjust, then do not need this step.

Step S306, when DMRS is mapped in/frequently in two-dimentional resource.

Consider the factors such as the complexity of DMRS expense and design, the invention provides a kind of processing method of downlink data of relay link.The method comprises: the number of the port of described downlink data of relay link transmission under setting diversity mode, when antenna for base station port number is greater than N, be set as N number of by the port number that described downlink data of relay link transmits, N is less than or equal to 4.Namely the transfer of data that to use in antenna port N number of in base station carries out under diversity transmission mode; Or base station adopts virtual-antenna port technique, is mapped as by emission port N number of.

Particularly, when antenna for base station port number exceedes some, the port number of restriction diversity transmission, ensures that the expense of DMRS is in rational scope, ensures the flexibility of DMRS design.Here restriction can be in the antenna port of base station, determine that a part carries out transfer of data, or uses virtual port technology, by the mode at different antennae port mapping identical data and DMRS, reaches the object of restriction diversity transmission port number.

Present invention also offers a kind of indicating means of demodulated reference signal port number, for the port number of base station to relay station instruction DMRS, ensure that receiving terminal accurately obtains the transmit port number of DMRS, thus implement corresponding detection algorithm.

Particularly, the port number of DMRS is indicated by the CRC mask of relaying Physical Broadcast Channel, and described CRC mask is identical with the CRC mask of LTE Physical Broadcast Channel;

Particularly, between the port number of DMRS and antenna for base station port number, set up mapping relations, implied the port number indicating described demodulated reference signal by antenna for base station port number.And mapping relations are: when antenna for base station port number is 1, described demodulated reference signal port number is 1, and when antenna for base station port number is more than or equal to 2, the port number of described demodulated reference signal is 2; Or when antenna for base station port number is 1 or 2, described demodulated reference signal port number is 1 or 2, when antenna for base station port number is more than or equal to 4, the port number of described demodulated reference signal is 4;

Particularly, mapping relations are set up between the port number of DMRS and the port number of base station public reference signal, concrete, relay station obtains described base station public reference signal port number by the CRC mask of base station physical broadcast channel, is implied the port number indicating described demodulated reference signal by base station public reference signal port number; Preferably, described mapping relations are that the port number of demodulated reference signal equals described base station public reference signal port number.

Or the port number of DMRS is indicated by the indicating bit in relay link downlink control signal.

It should be noted that, can perform in the computer system of such as one group of computer executable instructions in the step shown in the flow chart of accompanying drawing, and, although show logical order in flow charts, but in some cases, can be different from the step shown or described by order execution herein.

Be described in detail below in conjunction with the implementation procedure of example to the embodiment of the present invention.

In LTE/LTE-A system, for the difference of CP length, be divided into common CP (NormalCP) and expansion CP (Extend CP).Under common CP length, a subframe has 14 OFDM symbol; Under expansion CP length, a subframe has 12 OFDM symbol.Because CP length is different, the OFDM symbol position causing DMRS to map may change to some extent.Be described below by way of specific embodiment.

Example 1:

In example 1, suppose that DMRS that the present invention describes is used for the demodulation of R-PDCCH, and suppose that the transmission of R-PDCCH takies a part for the OFDM symbol that base station is transmitted to relay station in relay sub-frame.Concrete, supposing that R-PDCCH transmits the OFDM symbol number taken is N _r-PDCCH, wherein N _r-PDCCHdynamic or semi-static setting can be carried out by base station according to the capacity of relay link control channel; Also can appoint between base station and relay station, i.e. static state setting.Suppose dynamic or semi-staticly to arrange N _r-PDCCHvalue time, agreement $N_{R-\mathrm{PDCCH}}^{\min }\≤N_{R-\mathrm{PDCCH}}\≤N_{R-\mathrm{PDCCH}}^{\max },$ Wherein N _r-PDCCH ^minfor the minimum OFDM number that the R-PDCCH of agreement can take, N _r-PDCCH ^maxfor the maximum OFDM symbol number that the R-PDCCH of agreement can take; Work as N _r-PDCCHvalue static state setting time, suppose N _r-PDCCHvalue be about decided to be $N_{R-\mathrm{PDCCH}}=N_{R-\mathrm{PDCCH}}^{\mathrm{static}}.$

In this example, the design principle of the DMRS of R-PDCCH is, in a RB, the DMRS of same port is spaced apart 6 subcarriers at frequency domain.In time domain, N is set if dynamic or semi-static _r-PDCCHvalue, then DMRS map OFDM symbol for take minimum OFDM symbol number (i.e. N at R-PDCCH _r-PDCCH ^min) hypothesis under, first of R-PDCCH territory does not comprise CRS and last does not comprise the OFDM symbol of CRS; If static state setting N _r-PDCCHvalue, then DMRS time domain mapping OFDM symbol be in the OFDM symbol that takies of R-PDCCH first do not comprise CRS and last does not comprise the OFDM symbol of CRS.Here prerequisite is that hypothesis base station uses common subframe (non-MBSFN sub-frame) to relay station transmission data.When base station uses MBSFN sub-frame (namely backhaul link does not have CRS) to relay station transmission data, the DMRS of R-PDCCH adopts the pattern identical with during common sub-frame transmission.

Such as, the port number of suppose relay downlink control data diversity transmission is restricted to 2.When dynamic or semi-staticly arrange N _r-PDCCHvalue time, $N_{R-\mathrm{PDCCH}}^{\min }=3,$ $N_{R-\mathrm{PDCCH}}^{\max }=4$ Hypothesis under, when under common CP length, system bandwidth is greater than 10 RB, an example of the pattern of DMRS is as shown in Figure 4.Here suppose that the primary sign of R-PDCCH is the 4th OFDM symbol.Equally, the pattern shown in Fig. 4 is also applicable to static state setting N _r-PDCCHvalue time, when $N_{R-\mathrm{PDCCH}}^{\mathrm{static}}=3$ Time DMRS pattern.

In this example, the sub-carrier positions that hypothesis DMRS maps in RB is further determined according to Physical Cell Identifier, and concrete grammar is identical with the CRS mapping position defining method of LTE system.For the DMRS pattern shown in Fig. 4, the particular location mapped in a RB as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein k represents that the sub-carrier positions that DMRS maps in a RB, l represent the OFDM symbol position that DMRS maps, p ^dMRSrepresent the port numbering of DMRS, N _iD ^cellrepresent Physical Cell Identifier number.

When system bandwidth is less than or equal to 10 RB, suppose that the primary sign of R-PDCCH is the 5th OFDM symbol, at this time DMRS pattern is adjusted to as shown in Figure 5.The concrete mapping position of DMRS as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein the implication of parameters is same as described above.

Under expansion CP length, when system bandwidth is greater than 10 RB, under the DMRS design principle of this example, an example of DMRS pattern as shown in Figure 6.The mapping position concrete in a RB of DMRS becomes

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

In formula, parameters implication as hereinbefore.

Under expansion CP length, when system bandwidth is less than or equal to 10 RB, under the DMRS design principle of this example, DMRS pattern still as shown in Figure 6, just at this time supposes that the primary sign of R-PDCCH becomes the 5th OFDM symbol.DMRS pattern when the particular location that DMRS maps in a RB and system bandwidth are greater than 10 RB is identical.

In this example, if the REG of R-PDCCH is (Resource Element Group, referred to as resource element group) size identical with LTE REG size, so when R-PDCCH single port is transmitted, R-PDCCH data are still 2 to map according to DMRS port.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 2:

Under the hypothesis and DMRS design principle of example 1, the dynamic or semi-static configuration of the OFDM symbol number taken as R-PDCCH, or R-PDCCH take OFDM symbol number static configuration time, the example of another DMRS pattern is as shown in Fig. 7,8,9.Still hypothesis when the OFDM symbol number that R-PDCCH takies is dynamic or semi-static configuration time $N_{R-\mathrm{PDCCH}}^{\min }=3,$ $N_{R-\mathrm{PDCCH}}^{\max }=4;$ As the OFDM symbol number static state setting N that R-PDCCH takies _r-PDCCHvalue time $N_{R-\mathrm{PDCCH}}^{\mathrm{static}}=3.$

Fig. 7 is the DMRS pattern example of system bandwidth when being greater than 10 RB, mapped resource position concrete in a RB as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein the implication of each parameter is identical with example 1.

Fig. 8 represents the DMRS pattern example when being less than or equal to 10 RB in system bandwidth, mapped resource position concrete in a RB as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein the implication of each parameter as hereinbefore.

Under expansion CP length, DMRS pattern example as shown in Figure 9.It is identical with DMRS pattern when being less than 10 RB that system bandwidth is greater than 10 RB, and when just system bandwidth is greater than 10 RB, the primary sign of R-PDCCH is the 4th OFDM symbol, and the primary sign being less than or equal to R-PDCCH during 10 RB is the 5th OFDM symbol.The concrete resource location that the pattern of DMRS shown in Fig. 9 example maps in a RB as shown in the formula.

k＝{(v+v _shift)mod 6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein each meaning of parameters as hereinbefore.

In this example, if the size of the REG of R-PDCCH is identical with LTE REG size, so when R-PDCCH single port is transmitted, R-PDCCH data are still 2 to map according to DMRS port.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 3:

Under the hypothesis and DMRS design principle of example 1, the dynamic or semi-static configuration of the OFDM symbol number taken as R-PDCCH, or R-PDCCH take OFDM symbol number static configuration time, the invention provides method and pattern example that another DMRS designs.

The DMRS design principle of this example is, is greater than the pattern of the situation design DMRS of 10 RB for system bandwidth.When system bandwidth is less than or equal to 10 RB, if relay station does not receive the OFDM symbol that some is mapped with DMRS, then DMRS pattern when system bandwidth is less than or equal to 10 RB is the DMRS removed on original DM RS pattern basis in the symbol do not received.

Such as, suppose the OFDM symbol number static state setting that R-PDCCH takies, between base station and relay station, namely appoint the OFDM symbol number that R-PDCCH takies: $N_{R-\mathrm{PDCCH}}=N_{R-\mathrm{PDCCH}}^{\mathrm{static}},$ And hypothesis is under common CP length, when system bandwidth is greater than 10 RB, $N_{R-\mathrm{PDCCH}}^{\mathrm{static}}=4,$ When system bandwidth is less than or equal to 10 RB, $N_{R-\mathrm{PDCCH}}^{\mathrm{static}}=3.$ Suppose that R-PDCCH original position is the 4th OFDM symbol when system bandwidth is greater than 10 RB, when system bandwidth is less than or equal to 10 RB, R-PDCCH original position is the 5th OFDM symbol.Suppose that the diversity port number of R-PDCCH is restricted to 2 simultaneously.Under above hypothesis, when under common CP length, system bandwidth is greater than 10 RB, the DMRS pattern of R-PDCCH as shown in Figure 10.

The particular location that DMRS pattern shown in Figure 10 maps in a RB is as follows.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein k represents that the sub-carrier positions that DMRS maps in a RB, l represent the OFDM symbol position that DMRS maps, p ^dMRSrepresent the port numbering of DMRS.N _iD ^cellrepresent Physical Cell Identifier.

When system bandwidth is less than or equal to 10 RB, suppose that the primary sign of R-PDCCH is the 5th OFDM symbol.At this time under the design principle of the present embodiment, the pattern of DMRS becomes the form of Figure 11 on the basis of Figure 10, namely no longer maps DMRS in the 4th OFDM symbol.

The particular location that DMRS pattern shown in Figure 11 maps in a RB as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein the implication of each parameter as hereinbefore.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 4:

In this example, suppose that DMRS that the present invention describes is used for the demodulation of R-PDCCH, and suppose that the transmission of R-PDCCH takies a part for the OFDM symbol that base station is transmitted to relay station in relay sub-frame.Concrete, supposing that R-PDCCH transmits the OFDM symbol number taken is N _r-PDCCH, wherein N _r-PDCCHdynamic or semi-static setting can be carried out by base station according to the capacity of relay link control channel; Also can appoint between base station and relay station, i.e. static state setting.Suppose dynamic or semi-staticly to arrange N _r-PDCCHvalue time, agreement $N_{R-\mathrm{PDCCH}}^{\min }\≤N_{R-\mathrm{PDCCH}}\≤N_{R-\mathrm{PDCCH}}^{\max },$ Wherein N _r-PDCCH ^minfor the minimum OFDM number that the R-PDCCH of agreement can take, N _r-PDCCH ^maxfor the maximum OFDM symbol number that the R-PDCCH of agreement can take; Work as N _r-PDCCHvalue static state setting time, suppose N _r-PDCCHvalue be about decided to be $N_{R-\mathrm{PDCCH}}=N_{R-\mathrm{PDCCH}}^{\mathrm{static}}.$

In this example, the design principle of the DMRS of R-PDCCH is, in a RB, the DMRS of same port is spaced apart 6 subcarriers at frequency domain.In time domain, all DMRS only can be mapped in an OFDM symbol, and the symbol mapping this DMRS is the OFDM symbol not comprising CRS in R-PDCCH territory, and when CP length is determined, this OFDM symbol is fixed.Here prerequisite is that hypothesis base station uses common subframe (non-MBSFN sub-frame) to relay station transmission data.When base station uses MBSFN sub-frame (namely backhaul link does not have CRS) to relay station transmission data, the DMRS of R-PDCCH adopts the pattern identical with during common sub-frame transmission.

Such as, the port number of suppose relay downlink control data diversity transmission is restricted to 2.Under common CP length, an example of DMRS pattern as shown in figure 12.Figure 12 is applicable to downlink system bandwidth simultaneously and is greater than or less than the situation equaling 10 RB, and the primary sign that just in two kinds of situations, R-PDCCH maps is different.

In this example, the sub-carrier positions that hypothesis DMRS maps in RB is further determined according to Physical Cell Identifier, and concrete grammar is identical with the CRS mapping position defining method of LTE system.For the DMRS pattern shown in Figure 12, the particular location mapped in a RB as shown in the formula.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein k represents that the sub-carrier positions that DMRS maps in a RB, l represent the OFDM symbol position that DMRS maps, p ^dMRSrepresent the port numbering of DMRS, N _iD ^cellrepresent Physical Cell Identifier number.

Under expansion CP length, the OFDM symbol mapped at the DMRS of this example is the 5th OFDM symbol, repeats no more here.

In this example, if the REG of R-PDCCH is (Resource Element Group, referred to as resource element group) size identical with LTE REG size, so when R-PDCCH single port is transmitted, R-PDCCH data are still 2 to map according to DMRS port.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 5:

Under the hypothesis of example 2, this example provides a kind of DMRS method for designing when DMRS port number maximum limit is made as 4.In this example, the design principle of DMRS port 0,1 is identical with example 2; Adopt the mode of CDM+FDM orthogonal, concrete during DMRS4 port transmission, on the DMRS pattern basis of 2 ports, multiplexing 4 layers of CDM spread spectrum, wherein CDM spreads to time domain spread spectrum.In this example, no matter base station uses MBSFN sub-frame (namely backhaul link does not have CRS) or common subframe to transmit data to relay station, and the pattern of DMRS remains unchanged.

Under above hypothesis, DMRS pattern when system bandwidth is greater than 10 RB under common CP length as shown in figure 13.Spectrum-spreading unit when ellipse representation CDM in figure is multiplexing.Walsh code can be used during spread spectrum as spreading code, and such as length is Walsh code [1,1] and [1 ,-1] of 2.In Figure 13, DMRS port 0 and 2 is on the same resource multiplexing by the mode of CDM, and the mode that port one and 3 passes through CDM is on the same resource multiplexing.The resource mapping of DMRS in a RB is as follows.

k＝{(v+v _shift)mod6，6+(v+v _shift)mod6}

l＝{4，6}

$v_{\mathrm{shift}}=N_{\mathrm{ID}}^{\mathrm{cell}}\mathrm{mod}6$

Wherein k represents that the sub-carrier positions that DMRS maps in a RB, l represent the OFDM symbol position that DMRS maps, p ^dMRSrepresent the port numbering of DMRS, N _iD ^cellrepresent Physical Cell Identifier number.Under expansion CP length, DMRS maps OFDM symbol and is adjusted to l={6,7}, repeats no more here.

In this example, if the size of the REG of R-PDCCH is identical with LTE REG size, so when R-PDCCH transmit port is less than 2, R-PDCCH data are still 2 to map according to DMRS port.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 6:

In this example, suppose the coherent demodulation that the DMRS that the present invention describes transmits for downlink data of relay link, described data can be relay link downlink control datas, or the data of relay link downlink Physical Broadcast Channel, or the data etc. of diversity transmission in relay link downlink shared channel.

The DMRS design principle of this example is: DMRS port, two ports are identical with the resource location taken with resource overhead during four port transmission, just adopts the mode of CDM to ensure that the DMRS of each port is orthogonal when DMRS multiport transmits; The OFDM symbol that DMRS maps is the OFDM symbol not having CRS to transmit in common subframe (non-MBSFN sub-frame), and if base station uses MBSFN sub-frame to transmit data to relay station, the pattern of DMRS is identical with the DMRS pattern transmitted in common subframe.

Under above hypothesis, as shown in figure 14, the frequency domain position of DMRS is subcarrier k={3,9} to a pattern example of DMRS design, and time-domain position is OFDM symbol l={6,7,11,13}.Wherein the DMRS of each port is at frequency domain interval 6 subcarriers; The resource that DMRS takies when 1,2,4 port transmission is identical, just in same resource, uses the mode of CDM spread spectrum to ensure that the DMRS of different port is orthogonal during multiple port.Spectrum-spreading unit during ellipse representation CDM in figure.Walsh code can be selected during CDM as orthogonal code, such as [1,1] and [1 ,-1].When DMRS tetra-port transmission, the RE of 4 DMRS on same subcarrier is as a spectrum-spreading unit, and such as, when getting Walsh code as spreading code, Walsh code can be taken as:

$\left\{\begin{array}{c}\left[\mathrm{1,1,1,1}\right]\\ [1,-\mathrm{1,1},-1]\\ [\mathrm{1,1},-1,-1]\\ [1,-1,-\mathrm{1,1}]\end{array}\right.$

Here repeat no more.

If in order to the performance ensureing single RB channel estimating, DMRS also can be the frequency domain edge subcarrier of a RB in the mapping position of frequency domain, and the mapping subcarriers of such as DMRS is k={1,12}.

If the end position of the OFDM symbol that relay station can receive in a subframe is the 14th OFDM symbol, then the OFDM symbol position that DMRS maps can be l={6,7,13,14}.

It should be noted that the CRS pattern just schematically describing LTE system in the schematic diagram of this example, and do not represent the corresponding relation between CRS port number and DMRS port number.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 7:

In this example, suppose the coherent demodulation that the DMRS that the present invention describes transmits for downlink data of relay link, described data can be relay link downlink control datas, or the data of relay link downlink Physical Broadcast Channel, or the data etc. of diversity transmission in relay link downlink shared channel.

The DMRS design principle of this example is: resource overhead when DMRS port, two port transmission is identical with the resource location taken; The mode of CDM is adopted to ensure that the DMRS of each port is orthogonal during two port transmission, the expense of DMRS is increased during four port transmission, the mode of CDM+FDM (Frequency Division Multiplexing is called for short FDM) is adopted to ensure that each port is orthogonal; The OFDM symbol that DMRS maps is the OFDM symbol not having CRS to transmit in common subframe (non-MBSFN sub-frame), and if base station uses MBSFN sub-frame to transmit data to relay station, the pattern of DMRS is identical with the DMRS pattern transmitted in common subframe.

Under above hypothesis, a pattern example of DMRS design as shown in figure 15.The resource that when one of them port and two port transmission, DMRS takies is identical, and just same during two ports resource uses multiplexing two layers of the mode of CDM.Spectrum-spreading unit during ellipse representation CDM in figure.Walsh code can be selected during CDM as orthogonal code, such as [1,1] and [1 ,-1].When DMRS tetra-port transmission, port number is divided into two groups, such as { 0,1} is with { 2,3}, the DMRS of these two groups of ports uses the mode of FDM to keep orthogonal, in each group, uses the mode of CDM to ensure that the DMRS of two ports is orthogonal.

DMRS pattern shown in Figure 15 is l={6,7,11,13} in the OFDM symbol position that time domain takies.If the end position of the OFDM symbol that relay station can receive in a subframe is the 14th OFDM symbol, also the mapping symbols of DMRS can be adjusted to l={6,7,13,14}.

Under expansion CP length, two OFDM symbol that DMRS maps become l={5,6,9,11}.Equally, if the end position of OFDM symbol that relay station can receive in a subframe is the 12nd OFDM symbol, also the mapping symbols of DMRS can be adjusted to l={5,6,11,12}.

Under the hypothesis of this example, also DMRS can be defined as the two ends of a RB frequency domain in the mapping position of frequency domain, the performance of the channel estimating of single RB can be ensured like this.A DMRS pattern example as shown in figure 16.Here repeat no more.

It should be noted that the DMRS pattern described in this example also go for repeated link data space division multiplexing transmission mode under data demodulates.At this time the port number of DMRS and the number of layers of multiplexing transmission corresponding.Here repeat no more.

It should be noted that the schematic diagram in this example just schematically describes the CRS pattern of LTE system, and do not represent the corresponding relation between CRS port number and DMRS port number or number of layers.And when base station uses MBSFN sub-frame to relay station transmission data, in the OFDM symbol after the 3rd OFDM symbol, will not CRS be there is.

Should be appreciated that the DMRS pattern in this example just plays description and explains object of the present invention, and also paired not restriction of the present invention.

Example 8

In this example, a kind of example of repeated link data mapping method is provided.Concrete, when relaying link data transmits under diversity mode, in order to ensure the flexibility that corresponding DMRS designs and rational expense, the diversity port number of restriction repeated link diversity transmission.

In lte-a system, the antenna port of base station can expand to 8, and the diversity transmission of 8 ports can't bring than the more obvious gain of 4 port diversity, but corresponding DMRS but can be caused to design becomes comparatively complicated, and the expense of DMRS increases.Therefore, the diversity port number of repeated link transfer of data can be limited.Such as, when base station is configured with 8 antenna ports, only adopt 4 port diversity transmissions, or even 2 port diversity transmissions.The at this time corresponding DMRS only needing 4 or 2 ports.

Such as, the unified port number being defined as CRS in present sub-frame of the port number of downlink data of relay link diversity transmission.

Such as, when antenna for base station port number is greater than 2, the port number of relay link downlink control data transmission is restricted to 2.

Such as, when antenna for base station port number is greater than 4, the port number of downlink data of relay link diversity transmission is restricted to 4.

When limiting the port number of diversity transmission, can in antenna for base station port, select a part of port as the antenna port transmitted under diversity mode, the antenna port number of selection be the port number of diversity transmission.

When limiting the port number of diversity transmission, the method for virtual-antenna also can be adopted to carry out data-mapping.Such as, the antenna port of base station is that { 0,1,2,3,4,5,6,7}, the port number of diversity transmission is 2, so antenna port can be grouped into { 0,2,4,6} and { 1,3,5,7} is as two virtual ports.On these two virtual ports, map identical data and DMRS.At receiving terminal, DMRS and data are that use 2 ports transmit.

Example 9

Receiving terminal after receiving the data, before carrying out channel estimating, needs port number or the number of layers of knowing transfer of data, and namely the port number of corresponding DMRS or number of layers, carry out channel estimating to mate corresponding DMRS pattern.This example will provide the indicating means of some DMRS port numbers (or number of layers).

Under diversity transmission mode, can set up mapping relations between the DMRS port number of diversity transmission and CRS port number, the DMRS port number such as limiting diversity transmission is identical with CRS port number.When DMRS port number is identical with the port number of CRS, relay station receives the data of Physical Broadcast Channel, is obtained the port number of CRS transmission, thus obtain the DMRS port number of diversity transmission by the CRC mask of Physical Broadcast Channel.The acquisition of concrete CRS port number is identical with the preparation method of terminal in LTE, repeats no more here.

Under diversity transmission mode, can by the port number of the CRC mask instruction diversity transmission of repeated link Physical Broadcast Channel.Here CRC mask can adopt the design identical with the CRC mask of Physical Broadcast Channel in LTE system, repeats no more here.

Under diversity transmission mode, also can set up mapping relations between antenna for base station port number and diversity transmission port number.Such as when antenna for base station port number is greater than 2, diversity transmission port number is restricted to 2; Or when antenna for base station port number is greater than 4, diversity transmission port number is restricted to 4.This mapping relations limit between base station and relay station.After relay station obtains the information of antenna for base station port number, just can imply the port number obtaining diversity transmission.

Also can by DCI (the Downlink Control Information at repeated link, Downlink Control Information, be called for short DCI) middle increase indicating bit, by this indicating bit to the relay station instruction port number of diversity transmission or the number of layers of multiplexing transmission.

Device embodiment

According to embodiments of the invention, provide a kind of base station, this base station may be used for the transmission of downlink demodulation reference signals of relay link.

Figure 17 is the structured flowchart of the base station according to the embodiment of the present invention, and as shown in figure 17, this base station comprises memory module 1700, relating module 1710, mapping block 1720, sending module 1730.Below said structure is specifically described.

Memory module 1700, for storing the pattern of the demodulated reference signal from base-station transmission;

Relating module 1710, is connected to memory module 1700, for associating according to the port number of transfer of data or number of layers the described demodulated reference signal pattern stored in corresponding memory module;

Mapping block 1720, is connected to relating module 1710, when demodulated reference signal is mapped in corresponding by the correlation demodulation reference signal pattern for obtaining according to relating module-and frequency two-dimensional physical resource;

Sending module 1730, for transmitting corresponding demodulated reference signal.

Figure 18 is the block diagram of optimizing structure of the base station according to the embodiment of the present invention.As shown in figure 18, this base station comprises processing module 1810, adjustment submodule 1820, indication information generation module 1830, is specifically described below to said structure.

Processing module 1810, for setting the port number of repeated link transfer of data under diversity mode, when base station port number is greater than N (N > 1), is defined as N number of, N≤4 by port number.The method limited can be select N number of port transmission in antenna for base station port, or adopts the mode of virtual-antenna to be mapped as N number of by the antenna port number of base station.

Relating module 1710 also comprises adjustment submodule 1820, for adjusting the pattern of DMRS, comprises the adjustment of time orientation and/or the adjustment of frequency direction.Adjusting module 1820 comprises the first adjustment submodule 1821 and the second adjustment submodule 1822 further.The difference of the OFDM symbol that the first adjustment submodule 1821 data of being responsible for demodulation according to system bandwidth or DMRS take at time orientation adjusts the OFDM symbol position that described demodulated reference signal maps; Second adjustment submodule 1822 is the adjustment of the sub-carrier positions that DMRS pattern maps, and such as determines according to Physical Cell Identifier number the sub-carrier positions that described demodulated reference signal maps in Physical Resource Block.

Indication information generation module 1830, for generating indication information, described indication information is used for base station indicates port number from demodulated reference signal transmission to relay station or number of layers.

It should be noted that adjustment submodule described herein is optional module, only just can comprise this module when needing adjustment when DMRS pattern.

According to embodiments of the invention, provide a kind of relay station, this relay station is used for the process of downlink demodulation reference signals of relay link.

Figure 19 is the structured flowchart of the relay station according to the embodiment of the present invention.As shown in figure 19, this relay station comprises receiver module 1910, is specifically described below to said structure.

Receiver module 1910, for receiving the DMRS that sending module 1730 sends, this DMRS is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission.

Further, this relay station comprises indication information receiver module 1920, and for receiving the indication information that indication information generation module 1830 generates, this indication information is used for the port number of relay station determination repeated link DMRS.

System embodiment

According to embodiments of the invention, provide a kind of relay system, this relay system may be used for the transmission of downlink demodulation reference signals of relay link.

Figure 20 is the structured flowchart of the relay system according to the embodiment of the present invention, as shown in figure 20, relay system comprises base station 18 and relay station 19, wherein, this base station 18 is identical with the structure described in above-mentioned device embodiment with the structure of relay station 19, the implementation procedure of its concrete function carried out detailed description in device embodiment, did not repeat them here.

In sum, by method of the present invention and base station and relay station, solve the transmission problem of repeated link demodulated reference signal, ensure that the reliability of repeated link transfer of data, and can not the terminal in same community be had an impact.Meanwhile, port number during setting diversity transmission, under the prerequisite ensureing diversity transmission gain, reduces the expense of demodulated reference signal and the complexity of design.

Obviously, those skilled in the art should be understood that, above-mentioned of the present invention each module or each step can realize with general calculation element, they can concentrate on single calculation element, or be distributed on network that multiple calculation element forms, alternatively, they can realize with the executable program code of calculation element, thus, they can be stored and be performed by calculation element in the storage device, or they are made into each integrated circuit modules respectively, or the multiple module in them or step are made into single integrated circuit module to realize.Like this, the present invention is not restricted to any specific hardware and software combination.

The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (27)

1. a transmission method for downlink demodulation reference signals of relay link, is characterized in that, described method comprises:

When demodulated reference signal is mapped in-frequently in two-dimentional resource, wherein, described demodulated reference signal is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission;

Described method also comprises: the layer that described demodulated reference signal transmits with the port that described downlink data of relay link transmits or described downlink data of relay link associates corresponding.

2. method according to claim 1, it is characterized in that, described downlink data of relay link comprise following one of at least: the data of relay link downlink control data, repeated link Physical Broadcast Channel and the data of repeated link Physical Downlink Shared Channel, wherein, described relay link downlink control data comprise following one of at least: the data of repeated link Physical Downlink Control Channel, relay link downlink control format indication information, relay link downlink mixed automatic retransfer indication information.

3. method according to claim 1, is characterized in that, time described-frequently two-dimentional resource comprise in frequency direction the Physical Resource Block that the described downlink data of transmission distributes.

4. method according to claim 1, is characterized in that, time described-frequently two-dimentional resource comprise at time orientation the orthogonal frequency division multiplex OFDM symbol carrying described downlink data of relay link in a downlink relay sub-frame.

5. method according to claim 3, is characterized in that, according to the Physical Cell Identifier number sub-carrier positions that the described demodulated reference signal of adjustment maps in Physical Resource Block.

6. method according to claim 4, is characterized in that, the OFDM symbol position that described demodulated reference signal maps is fixing in Physical Resource Block.

7. method according to claim 4, is characterized in that, adjusts the OFDM symbol position of described demodulated reference signal mapping according to system bandwidth; Or

The difference of the OFDM symbol taken according to described downlink data of relay link adjusts the OFDM symbol position that described demodulated reference signal maps.

8. method according to claim 1, it is characterized in that, under transmit diversity transmission mode, described demodulated reference signal is corresponding with the port association that described downlink data of relay link transmits, wherein, when described downlink data of relay link transmits at the port of multiple described downlink data of relay link transmission, the demodulated reference signal that association corresponds to different described downlink data of relay link transmit port is mutually orthogonal.

9. method according to claim 1, it is characterized in that, under space division multiplexing transmission mode, described demodulated reference signal pattern associates corresponding with the number of layers that described downlink data of relay link transmits, when carrying out multilayer transmission, the demodulated reference signal that association corresponds to each layer is mutually orthogonal.

10. method according to claim 8 or claim 9, is characterized in that, described orthogonal manner comprise following one of at least: time division multiplexing TDM, frequency division multiplex FDM, code division multiplex CDM.

11. methods according to claim 1, is characterized in that, described method also comprises:

The port number of described downlink data of relay link transmission under setting diversity mode, when antenna for base station port number is greater than N, be set as N number of by the port number that described downlink data of relay link transmits, N is less than or equal to 4.

12. methods according to claim 11, is characterized in that, the mode of setting is:

The transfer of data that to use in antenna port N number of in base station carries out under diversity transmission mode; Or

Base station adopts virtual-antenna port technique, data transmission port is mapped as N number of.

13. methods according to claim 11, is characterized in that, the number of the port of described downlink data of relay link transmission comprises one of following:

2,4, the port number of public reference signal CRS in present sub-frame.

14. methods according to claim 1, is characterized in that, described method also comprises:

Base station is to the port number of relay station instruction downlink demodulation reference signals of relay link, and described indicating means is indirect indicating means and/or direct indicating means.

15. methods according to claim 14, is characterized in that, described indirect indicating means comprises one of following:

The first mapping relations between the port number of described demodulated reference signal and antenna for base station port number are set up in described base station, and indicate the port number of described demodulated reference signal according to described first mapping relations;

Described base station indicates the port number of described demodulated reference signal to described relay station by the CRC mask of repeated link Physical Broadcast Channel;

The second mapping relations between the port number of described demodulated reference signal and the port number of base station public reference signal are set up in described base station, and indicate the port number of described demodulated reference signal according to described second mapping relations.

16. methods according to claim 15, the port number of described demodulated reference signal and the first mapping relations of antenna for base station port number are set up in described base station, and described first mapping relations comprise one of following:

When antenna for base station port number is 1, the port number of described demodulated reference signal is 1, and when antenna for base station port number is more than or equal to 2, the port number of described demodulated reference signal is 2; Or

When antenna for base station port number is 1 or 2, the port number of described demodulated reference signal is 1 or 2, and when antenna for base station port number is more than or equal to 4, the port number of described demodulated reference signal is 4.

17. methods according to claim 15, after the second mapping relations between the port number of described demodulated reference signal and the port number of base station public reference signal are set up in described base station, described method also comprises:

Described relay station obtains described base station public reference signal port number by the CRC mask of base station physical broadcast channel, is obtained the port number of described demodulated reference signal by described second mapping relations;

Described mapping relations are, the port number of described demodulated reference signal equals described base station public reference signal port number.

18. methods according to claim 14, is characterized in that, described direct indicating means comprises:

The port number of described downlink demodulation reference signal is indicated by the indicating bit in relay link downlink control signal.

19. 1 kinds of base stations, is characterized in that, described base station comprises:

Memory module, for storing the demodulated reference signal pattern from described base-station transmission;

Relating module, for associating according to the port number of transfer of data or number of layers the described demodulated reference signal pattern stored in corresponding memory module;

Mapping block, when demodulated reference signal is mapped in corresponding by the demodulated reference signal pattern for obtaining according to relating module-the two-dimentional resource of frequency;

Sending module, for transmitting corresponding demodulated reference signal, wherein, described demodulated reference signal is non-precoded reference signal, for carrying out coherent demodulation to downlink data of relay link.

20. base stations according to claim 19, described relating module comprises adjustment submodule, for adjusting described demodulated reference signal pattern at time orientation and/or frequency direction.

21. base stations according to claim 20, adjustment submodule also comprises,

First adjustment submodule, for adjusting the orthogonal frequency division multiplex OFDM character position that described demodulated reference signal maps according to system bandwidth; Or the difference of the OFDM symbol taken according to described downlink data of relay link adjusts the OFDM symbol position that described demodulated reference signal maps;

Second adjustment submodule, for adjusting the sub-carrier positions that described demodulated reference signal maps in Physical Resource Block according to Physical Cell Identifier number.

22. base stations according to claim 19, described base station also comprises processing module, for the port number of downlink data of relay link transmission described under setting diversity mode, when antenna for base station port number is greater than N, be set as N number of by the port number that described downlink data of relay link transmits, N is less than or equal to 4.

23. base stations according to claim 22, described processing module determines N number of port transmitted as described downlink data of relay link in the antenna port of base station; Or

The mode of virtual port is adopted to be mapped as N number of by the port number that described downlink data of relay link transmits.

24. base stations according to claim 19, described base station also comprises indication information generation module, for generating relay link downlink indication information, described relay link downlink indication information is used for base station corresponds to port number from the described downlink data of relay link transmission of described demodulated reference signal to relay station instruction association or number of layers.

25. base stations according to claim 24, described indication information generation module indicates one of in the following manner:

Described relay link downlink indication information is the CRC mask of repeated link Physical Broadcast Channel, and the port number of described demodulated reference signal is indicated by the CRC mask of repeated link Physical Broadcast Channel;

Described relay link downlink indication information is the indication information of antenna for base station port number, the first mapping relations between the port number of described demodulated reference signal and antenna for base station port number are set up in described base station, and indicate the port number of described demodulated reference signal according to described first mapping relations;

Described indication information is the indication information of base station public reference signal port number, the second mapping relations between the port number of described demodulated reference signal and base station public reference signal port number are set up in described base station, and indicate the port number of described demodulated reference signal according to described second mapping relations.

26. 1 kinds of relay stations, is characterized in that, comprising:

Receiver module, for receiving downlink demodulation reference signals of relay link, described downlink demodulation reference signals of relay link is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission;

Described relay station also comprises: indication information receiver module, for receiving the described relay link downlink indication information that described indication information generation module generates, described relay link downlink indication information is used for port number or the number of layers that relay station determines to associate the described downlink data of relay link transmission corresponding to described demodulated reference signal.

27. 1 kinds of relay systems, is characterized in that, comprising: base station and relay station, wherein,

Described base station comprises:

Memory module, for storing the demodulated reference signal pattern from described base-station transmission;

Relating module, for according to the described demodulated reference signal pattern stored in the port number of transfer of data or the corresponding described memory module of number of layers association;

Mapping block, when demodulated reference signal is mapped in corresponding by the demodulated reference signal pattern for obtaining according to described relating module-the two-dimentional resource of frequency;

Sending module, for transmitting corresponding demodulated reference signal, wherein, described demodulated reference signal is non-precoded reference signal, for carrying out coherent demodulation to downlink data of relay link;

Described relay station comprises:

Receiver module, for receiving downlink demodulation reference signals of relay link, described downlink demodulation reference signals of relay link is non-precoded reference signal, for the coherent demodulation of downlink data of relay link transmission.