CN104767601B - The method and system of reference signal are assigned under multiple antennas environment - Google Patents

Abstract

The present invention discloses a method and system for assigning reference signals to antennas and nodes in a wireless communication system. The wireless communication system includes N transmitting nodes, where N is an integer, and N≧1. The transmitting node transmits the reference signal in the first time slot and the second time slot in the subframe via the same bandwidth. Each node has at least one transmit antenna, where different nodes may have different numbers of transmit antennas. The reference signals are of two different types, a first type of reference signal is used for demodulation and a second type of reference signal is used for measurement. Assigning reference signals of the first type to a plurality of transmit nodes having at least one transmit antenna in the first and second time slots in the predefined bandwidth, and in the first and second time slots in the predefined bandwidth At least one transmitting node having at least one transmitting antenna is assigned the second type of reference signal in at least one of the two time slots.

Description

Method and system for assigning reference signal in multi-antenna environment

technical field

The present invention relates to a method and system for assigning reference signals to antennas and nodes in a wireless communication system.

It also relates to computer programs for said methods and systems.

Background technique

In communication systems, different kinds of reference signals are used. A reference signal is used to estimate the channel required to enable coherent demodulation of received signals containing control and data information. Another reference signal is used for channel quality measurement and enabling scheduling.

For example, in 3GPP LTE uplink, the reference signal used for coherent demodulation is called demodulation reference signal (DRS), while the reference signal used for channel quality measurement is called sounding reference signal (SRS).

Both SRS and DRS reference signals in LTE include a cell-specific base sequence with a predefined length and a corresponding cyclic shift in time domain. In LTE uplink, the base sequences are Zadoff-Chu (ZC) sequences or computer generated (CG) sequences. When the length of the base sequence is greater than 24 subcarriers, the ZC sequence is used as the base sequence. Otherwise, computer generated (CG) sequences were used. These two sequences have the advantage of having a constant amplitude in the time domain and frequency domain, which is just in line with the requirements of the uplink reference signal (RS). A cyclic shift is a linear phase rotation applied to the base sequence in the frequency domain. This linear phase shift in the frequency domain is equivalent to a cyclic shift in the time domain. Different values of cyclic shift are used to generate different orthogonal reference signals within a cell from a base sequence.

In a multi-user communication system where multiple users with one transmit antenna simultaneously transmit in the same frequency band, as in LTE uplink DRS corresponding to multi-user MIMO or LTE uplink SRS, one cyclic shift is used for A reference signal for each user is generated. Since the reference signals corresponding to the users are orthogonal, the cyclic shift value and the reference signals can be used to separate different users at the receiver side.

In LTE uplink, predefined and distinct symbols in an uplink subframe are dedicated to transmitting reference signals (RS), which are illustrated in FIG. 1 . In case of normal cyclic prefix (CP), DRS occupies the 4th symbol of each uplink slot and SRS is transmitted in the last symbol of some subframes configured by eNB. The transmission of DRS and SRS for each user equipment (UE) is independent. If a UE is scheduled in multiple resource blocks (RBs) in a subframe for transmitting the Physical Uplink Shared Channel (PUSCH), then the UE will A DRS with a length equal to the scheduled bandwidth is transmitted on symbols. The transmission bandwidth and subframe of the SRS are configured by the eNB. Even if the UE is not scheduled for data or control transmission, it may still transmit SRS in the last symbol of the second slot in the configured SRS transmission subframe.

For uplink DRS, multiple users use different cyclic shifts of the base sequence and transmit simultaneously only in case of uplink multi-user MIMO transmission. Otherwise, different users are separated by FDM and TDM. More precisely, when a single user is scheduled in a group of resource blocks and a subframe in the LTE uplink, since there is only one transmit antenna, only one DRS is needed, and thus only one cyclic shift is used, The rest of the cyclic shifts are idle. On the other hand, for SRS, multiple users are usually scheduled in the same time-frequency resource and separated by different cyclic shifts of the base sequence.

In the case of MU-MIMO and SRS, for DRS, the cyclic shifts must be assigned to different users in such a way that the corresponding time shift between the two users is larger than the channel delay spread. Otherwise, channels corresponding to different users will interfere with each other when channel estimation is performed at the receiver. Therefore, not all available cyclic shifts of the base sequence can actually be used.

Assume a situation where an LTE system operates with a 5MHz bandwidth under a typical urban area (TU) channel model, where the UE speed is 3km/h. This is a typical wireless communication channel. According to LTE Release 8, a total of eight cyclic shifts are available for SRS and DRS, ie up to eight users can be code multiplexed together. If successive cyclic shifts are assigned to different users in the frequency domain, the time shift between users is about 32 samples, which is smaller than the TU channel delay spread (39 samples). Therefore, in order to give each user sufficient protection against multipath at the receiver, at most every other cyclic shift must be assigned to each user, which means that under the assumption of a TU channel, only Four are code multiplexed together.

LTE-Advanced is an evolution of LTE where a User Equipment (UE) or Relay Node (RN) has up to four transmit antennas and it is important to know the channels from all transmitter antennas to the receiver antennas because this information is used in It is used to select the modulation and coding scheme for data transmission and is also used to select the precoding matrix to be used for transmission. A precoding matrix taken from a codebook of available precoding matrices is selected by the receiver to match the channel and improve transmission quality. Data and DRS are precoded by the same precoding matrix, while SRS is not precoded. Therefore, assuming SRS allocation is considered for this case, one SRS needs to be transmitted from each of the UE transmit antennas. When supporting user equipment or relay nodes with multiple antennas, a higher number of cyclic shifts must be allocated per UE or RN compared to LTE in order to distinguish each antenna from each user. In this case, the available eight probe sequences are quickly exhausted.

Therefore, the problem is how to estimate channels from multiple transmit antennas for quality estimation and scheduling, ie how to sound channels from UEs or RNs with multiple transmit antennas.

Another problem is how to sound channels from multiple users, assuming some users have multiple transmit antennas.

Furthermore, a related issue is how to keep signaling overhead and reference signal overhead to a minimum.

A related question is how to keep the level of interference as low as possible.

Patent document WO 2009/017363 relates to a method for combining a reference signal from a user equipment (UE) that does not have any other signal transmissions in the corresponding transmission time interval (TTI) with a UE that also has data transmissions in the corresponding TTI A reference signal of another UE, or a method and apparatus for multiplexing with a control signal and a reference signal from another UE transmitted in a corresponding TTI. A multiplexed reference signal from a UE without any other signal transmission in the corresponding TTI may serve as a sounding reference signal to enable the serving base station to apply link adaptation to subsequent signals transmitted by the UE, or the reference signal Can serve as a reference signal to convey status information such as resource requests or service requests. In this document, only the problem of a limited number of SRSs is addressed. The other mentioned problems still exist.

Contents of the invention

The above problems are solved by a method and a system for assigning reference signals to antennas and nodes in a wireless communication system according to the appended claims.

One advantage of the method according to the invention is that the overhead is the same as in LTE when assigning more Sounding Reference Signals (SRS) to different users and different transmit antennas.

Another advantage is that the level of interference between different reference signals is reduced.

A further advantage of the method according to the invention is that there is less signaling overhead for indicating the cyclic shift value.

If a reference signal of the second type corresponding to at least one transmit antenna is assigned to the first time slot, and if a reference signal of the second type corresponding to the remaining transmit antennas is assigned to the second time slot, another implementation under this environment is achieved advantage. A further advantage is achieved by this: with a constant total transmit power of the user equipment, the transmit power per antenna becomes higher.

According to another embodiment, it is an advantage that a reference signal of the second type corresponding to at least one node is assigned to the first time slot and a reference signal of the second type corresponding to the remaining nodes is assigned to the second time slot.

According to yet another embodiment, it is an advantage that a first time slot is assigned a reference signal of the second type corresponding to at least one first node and a second time slot is assigned a reference signal of the second type corresponding to at least one second node signal, and assigning to the first time slot a reference signal of the second type corresponding to at least one transmit antenna of at least one third node, and assigning to the second time slot corresponding to the remaining transmit antenna of the at least one third node A second type of reference signal.

Furthermore, it is an advantage in this environment that the second type of reference signal assigned to the first slot is assigned a cyclic shift value different from the cyclic shift value assigned to the second type of reference signal assigned to the second slot. bit value.

According to another embodiment, it is an advantage that a reference signal of the second type assigned to a first time slot is assigned a cyclic shift value equal to a cyclic shift value assigned to a reference signal of the second type assigned to a second time slot. bit value.

Another advantage in this context is achieved if the antenna is a virtual antenna and if the method further comprises the steps of:

- Apply a precoding matrix/vector to each reference signal before transmission.

Furthermore, the following is an advantage in this context: The first type of reference signal is a demodulation reference signal (DRS).

Another advantage in this context is achieved if the second type of reference signal is a sounding reference signal (SRS).

Furthermore, it is an advantage in this context that reference signals of the first type are precoded by a precoding matrix/vector, whereas reference signals of the second type are not precoded by a precoding matrix/vector.

Furthermore, it is an advantage in this context that the node is a User Equipment (UE), a Relay Node (RN) or a mix of UE and RN in a wireless communication system such as LTE or LTE-Advanced.

One advantage of the system according to the invention is that when assigning more sounding reference signals (SRS) to different users and different transmit antennas, the overhead is the same as in LTE.

Another advantage is that the level of interference between different reference signals is reduced.

A further advantage of the system according to the invention is that there is less signaling overhead for indicating the cyclic shift value.

If the control device also assigns a reference signal of the second type corresponding to at least one transmit antenna to the first time slot, and assigns a reference signal of the second type corresponding to the remaining transmit antennas to the second time slot, then the implementation in this environment is achieved Another advantage. A further advantage is achieved by this: with a constant total transmit power of the user equipment, the transmit power per antenna becomes higher.

According to another embodiment, the following is an advantage: the wireless communication system comprises P scheduled nodes, where P is an integer and P≧2. The control means also assigns to the first time slot a second type of reference signal corresponding to at least one scheduled node. The control means also assigns reference signals of a second type corresponding to the remaining scheduled nodes to the second time slot.

Furthermore, in this context it is an advantage that the control means also assigns to the first time slot a reference signal of the second type corresponding to at least one first scheduled node and to the second time slot a reference signal corresponding to at least one second scheduled node A second type of reference signal for the node. The control means also assigns to the first time slot a second type of reference signal corresponding to at least one transmit antenna of the at least one third scheduled node, and assigns to the second time slot a reference signal corresponding to the at least one third scheduled node Reference signals of the second type for the remaining transmit antennas.

This is achieved if the control means also assigns a cyclic shift value to a reference signal of the second type assigned to the first time slot that is different from a cyclic shift value assigned to a reference signal of the second type assigned to the second time slot Another advantage of the environment.

According to another embodiment, it is an advantage that the control means also assigns to the reference signal of the second type a cyclic shift value equal to the cyclic shift value assigned to the reference signal of the second type assigned to the second time slot.

Furthermore, it is an advantage in this context that the first type of reference signal is a demodulation reference signal (DRS).

Another advantage in this case is achieved if the second type of reference signal is a Sounding Reference Signal (SRS).

Furthermore, it is an advantage in this context that the node is a User Equipment (UE), a Relay Node (RN) or a mix of UE and RN in a wireless communication system such as LTE or LTE-Advanced.

The above problem is also solved by using at least one computer program product according to technical solution 21. Said at least one computer program product is directly loadable into the internal memory of at least one digital computer and comprises software code portions for performing the steps of the method according to the invention when said at least one product is run on at least one computer.

One advantage of this solution is that the overhead is the same as in LTE when more Sounding Reference Signals (SRS) are assigned to different users and different transmit antennas.

Another advantage is that the level of interference between different reference signals is reduced.

Yet another advantage of this solution is that there is less signaling overhead for indicating the cyclic shift value.

It will be noted that the term "comprising" used in this description is intended to indicate the presence of a given characteristic, step or component, but does not exclude the presence of one or more other characteristics, features, integers, components or groups thereof. Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Description of drawings

FIG. 1 shows a diagram illustrating the positions of DRS and SRS in an uplink subframe of LTE;

2 is a flowchart of a method for assigning reference signals to antennas and nodes in a wireless communication system according to the present invention;

FIG. 3 illustrates transmitting multiple SRSs for a user equipment (UE) with multiple antennas on two slots;

Figure 4 schematically reveals the relationship between the virtual antenna and the physical antenna;

FIG. 5 illustrates transmitting multiple SRSs from different user equipments on two time slots;

Figure 6 illustrates a first alternative for a scenario where multiple user equipments with multiple transmit antennas have to be supported;

Figure 7 illustrates a second alternative for a scenario where multiple user equipments with multiple transmit antennas must be supported;

FIG. 8 illustrates mixed transmission of multiple SRSs from different UEs and different antennas;

FIG. 9 shows a scenario where only SRS is transmitted on the DRS symbols of each slot;

Figure 10 schematically discloses different methods of assigning reference signals on time slots using code multiplexing to different nodes with multiple antennas;

Figure 11 reveals that SRS and DRS use different bandwidth allocations that are orthogonalized due to a certain code in the time domain;

12 is a block diagram of a system for assigning reference signals to antennas and nodes in a wireless communication system according to the present invention; and

Fig. 13 schematically illustrates a computer program product according to the present invention.

Detailed ways

A flowchart of a method of assigning reference signals to antennas and nodes in a wireless communication system according to the present invention is disclosed in FIG. 2 . The wireless communication system includes N transmitting nodes, where N is an integer, and N≧1. The transmitting node transmits the reference signal in the first time slot and the second time slot in the subframe via the same bandwidth. Furthermore, each node has at least one transmit antenna, and different nodes may have different numbers of transmit antennas. There are two different types of reference signals, a first type of reference signal is used for demodulation and a second type of reference signal is used for measurement. The method begins at block 50 . The method continues at box 52 by asking the following question: Are there any reference signals of the first type? If the answer is no, the method continues with step 52 again. On the other hand, if the answer is yes, then the method continues at block 54 with the step of assigning a first type of reference to a plurality of transmitting nodes having at least one transmitting antenna in the first and second time slots in the predefined bandwidth Signal. Thereafter, the method continues at block 56 with the step of assigning a second type of reference signal to at least one transmitting node having at least two transmitting antennas in at least one of the first and second time slots in said predefined bandwidth. The method completes at block 58 .

According to a preferred embodiment of the method according to the invention, a first time slot is assigned a reference signal of the second type corresponding to at least one transmit antenna, and a second time slot is assigned a reference signal of the second type corresponding to the remaining transmit antennas .

According to another preferred embodiment, the first time slot is assigned a reference signal of the second type corresponding to at least one node, and the second time slot is assigned reference signals of the second type corresponding to the remaining nodes.

According to another preferred embodiment, a reference signal of the second type corresponding to at least one first node is assigned to the first time slot, a reference signal of the second type corresponding to at least one second node is assigned to the second time slot, and assigning a reference signal of a second type corresponding to at least one transmit antenna of the at least one third node to the first time slot, and assigning a second type of reference signal corresponding to the remaining transmit antennas of the at least one third node to the second time slot the reference signal.

According to a first alternative of the method according to the invention, a reference signal of the second type assigned to a first time slot is assigned a cyclic shift value different from that assigned to a reference signal of the second type assigned to a second time slot Rotate value.

According to a second alternative, the reference signal of the second type assigned to the first time slot is assigned a cyclic shift value equal to the cyclic shift value assigned to the reference signal of the second type assigned to the second time slot.

In LTE or LTE-Advanced, this is performed by control signaling in the physical layer from the receiver to the transmitter using the Physical Downlink Control Channel (PDCCH) or in another channel at any layer above the physical layer assignment in the embodiments described here.

In addition, if the transmitting antenna is a virtual antenna, the method also includes the following steps:

- Apply a precoding matrix/vector to each demodulation reference signal before transmission.

According to a preferred embodiment of the method, the first type of reference signal is a demodulation reference signal (DRS), which is precoded by a precoding matrix/vector, and the second type of reference signal is a sounding reference signal (SRS), which Not precoded by precoding matrix/vector, but transmitted by antenna.

It is assumed without loss of generality that only one node with multiple antennas is to be probed. In order to sound the channel of a node with multiple antennas, one SRS per antenna is required. Multiple antennas of a node to be detected are divided into two antenna groups. The cyclic shift in the SRS group of the first slot is assigned because the SRS of the antennas in the first group and the available cyclic shift in the SRS group of the second slot are used for the antennas in the second group SRS. The cyclic shift for each antenna group can be the same or different. In this case, the SRS for each antenna is transmitted once in a subframe using SRS and DRS multiplexing. Because SRS has lower performance requirements for demodulation than DRS, the transmission of SRS may be sparser than that of DRS. In LTE, SRS is only transmitted in a configured subframe by the eNB used to transmit SRS, and SRS is only transmitted in the last symbol of a configured subframe. According to this method, only a part of antennas of a specific node transmits SRS on DRS symbols in one slot.

It should be noted that the term user equipment (UE) will be used as an embodiment of a node in the following detailed description and associated figures, but it is obvious to those skilled in the art that the node in the present invention is not limited to user equipment, but a wireless communication Other types of nodes in the system, such as relay nodes, are also within the scope of the description and appended claims.

Transmission of multiple SRSs for one UE with multiple antennas is disclosed in FIG. 3 on two slots. Assume that the total number of available DRS cyclic shifts is eight, namely CS0 to CS7, and UE A with a single antenna is scheduled to have multiple resource blocks (RBs) for Physical Uplink Shared Channel (PUSCH) transmission. CS0 is used for DRS for this UE to demodulate PUSCH, and CS1 to CS7 are not used. The unused cyclic shifts CS1 to CS7 on the two slots respectively form two SRS groups. UE B has two transmit antennas (antenna 1 and antenna 2), and requires two SRSs to sound the corresponding channel.

Therefore, UE B's two SRSs can be transmitted using the unused DRS cyclic shift, ie UE B's SRS is multiplexed with UE A's DRS using CDM. The SRS for antenna 1 and antenna 2 are transmitted in slot 1 and slot 2, respectively. The cyclic shifts assigned to the SRSs of Antenna 1 and Antenna 2 can be the same or different, for example, CS4 is used for Antennas 1 and 2, or CS4 and CS5 are used for SRSs of Antennas 1 and 2, respectively. The interference level between UE B's SRS and UE A's DRS is reduced due to better allocation of cyclic shifts on each slot. When the same cyclic shift is assigned to each group, the signaling overhead to indicate the cyclic shift value is also reduced since only one cyclic shift needs to be indicated. Furthermore, Antenna 1 and Antenna 2 can transmit full power, which is not the case if the allocation is made on a single time slot.

The "antenna" mentioned above may be a physical antenna or a virtual antenna. Figure 4 schematically discloses the relationship between the virtual antenna and the physical antenna. For each virtual antenna, the transmitted SRS is a precoded SRS. For example, the UE has four physical antennas and the two precoding vectors are [1 1 1 1] ^T and [1 -1 1 -1] ^T or columns of any other orthogonal matrix. In the first slot, the transmitted SRS is [1 1 1 1] ^T *CS4, and the SRS in the second slot is [1 -1 1 -1] ^T *CS4.

The two SRS resource groups on the two time slots can also be assigned on a user-by-user basis. In this case, multiple users are divided into two groups. The cyclic shifts available on the first slot, or first SRS group, are assigned to the first group of users, and the cyclic shifts available on the second slot are assigned to the second group of users. This case is based on the assumption that, as mentioned above, the UE does not need to transmit SRS twice in one subframe, and thus different user equipments can be supported on each slot. As in the previous case, the cyclic shift value allocated to the user equipment on each slot may be the same or different. It is worth mentioning that the precoded case can also be applied to the per-user separation scenario.

The transmission of multiple SRSs from different user equipments on two slots is disclosed in FIG. 5 . It is assumed that UE A only uses one cyclic shift CS0 as DRS to demodulate PUSCH and implement frequency hopping. For each SRS resource group, there are seven available cyclic shifts, namely CS1 to CS7. UE B and UE C need to transmit SRS for uplink channel detection. Each UE needs one SRS. UE B's SRS is transmitted in the first slot using the assigned cyclic shift (CS4) from the first SRS resource group, and UE C is transmitted in the first slot using the assigned cyclic shift (CS4) from the second SRS resource group The SRS is transmitted in the second slot. The SRS sequences allocated to UE B and UE C may be the same or different. Multiplexing between SRS and DRS is shown in FIG. 5 .

A scenario where multiple user equipments with multiple transmit antennas must be supported will now be described. In this case, there are multiple user equipments transmitting SRS, and each UE needs multiple SRSs. There are two alternative ways to assign each UE the available cyclic shifts in the two SRS resource groups.

A first alternative or separation by antenna is disclosed in FIG. 6 . The multiple antennas of each UE are divided into two groups, and each antenna group transmits SRS in one slot.

A second alternative or per-user separation is disclosed in FIG. 7 . All user equipments transmitting SRS are divided into two groups, and each user equipment group transmits SRS in one time slot.

The assumptions about PUSCH transmitting UE A are the same as in the previous two examples. In this example, no frequency hopping is assumed. There are two user equipments (UE B and UE C) transmitting SRS, each UE has two transmit antennas.

Mixed allocation will now be described. In this method, separation into two different groups to be allocated on two time slots is done on an antenna separation basis and on a user separation basis. Each group contains SRSs for certain antennas and certain users, and are allocated to different time slots as mentioned before.

The mixed transmission of multiple SRSs from different user equipments and different antennas is disclosed in FIG. 8 . Assume the following situation is considered: there is one UE (UE A) transmitting DRS, and there are three different user equipments (UE B, UE C and UE D), each of which has two transmit antennas to be detected. UE B and UE C can be separated in user mode, and different antennas corresponding to UE D can be separated in antenna mode.

The eNB will schedule multiple RBs for DRS transmission and indicate the cyclic shift for DRS. Scheduling information is transmitted in the PDCCH, including RB allocation, cyclic shift index for DRS, MCS and so on. After the UE receives the scheduling information in the PDCCH, it will transmit data and DRS in a certain allocated bandwidth. For SRS transmission, the PDCCH can be used to indicate the allocated bandwidth and the index of the cyclic shift used for SRS, or this information can be configured by the eNB through higher layer signaling such as RRC signaling.

All the examples given above assume that there is one UE to be scheduled. Actually sometimes no UE is scheduled. For this case, all cyclic shifts are available and can be used to transmit SRS, ie only SRS is transmitted in the DRS symbol position of each slot, which is illustrated in FIG. 9 .

Different methods of assigning reference signals on time slots using code multiplexing to different nodes with multiple antennas are schematically revealed in Fig. 10 . Figure 10 summarizes examples and scenarios in one scheme by outlining per-user separation or per-antenna separation. Different groups of SRS corresponding to users or antennas are shown by numbers 1, 2 and 3. As described above, the sounding and demodulation reference signals are multiplexed. Method C indicates a case where allocation of sounding reference signals is performed on only one slot. In this method, groups 1, 2 and 3 are code-multiplexed together. Both method B and method A describe the case of sounding allocation on two time slots. Method B indicates allocation over two slots with groups 1 and 2 using different cyclic shifts. In this case, the cyclic shifts are allocated over two slots, providing better separation and less interference between them than in the first case. Method A describes the case of allocation over two slots, where only cyclic shifts are used for the different allocations. As mentioned above, with this solution less interference and less signaling overhead is guaranteed.

Fig. 11 reveals that the SRS bandwidth and the DMRS bandwidth are not equal as long as they are kept orthogonal. Preferably, this orthogonal property is achieved by means of orthogonal cover codes in the time domain.

A block diagram of a system 10 for assigning reference signals to antennas and nodes in a wireless communication system 12 in accordance with the present invention is disclosed in FIG. 12 . In general, the wireless communication system 12 includes N transmitting nodes 14 ₁ , . . . , 14 _N , where N is an integer, and N≧1. Only two transmitting nodes 14 ₁ , 14 ₂ are disclosed in Fig. 12 for simplicity. The transmitting node transmits the reference signal in the first time slot and the second time slot in the subframe via the same bandwidth. Each transmitting node has at least one transmitting antenna 16 ₁₁ , . . . , 16 _N1 , 16 _N2 , and different nodes may have different numbers of transmitting antennas. In the system 10 disclosed in FIG. 12 , the transmitting node 14 ₁ has two transmitting antennas 16 ₁₁ and 16 ₁₂ , and the transmitting node 14 ₂ has only one transmitting antenna 16 ₂₁ . It should be noted that there are two different types of reference signals, a first type of reference signal is used for demodulation and a second type of reference signal is used for measurement. It can be seen clearly from FIG. 12 that the system 10 also includes a control device 18 connected to the wireless communication system 12 and directed to at least one transmit antenna 16 in a first time slot and a second time slot in a predefined bandwidth. A plurality of transmitting nodes 14 _x of ₂₁ , 14 ₂ in Fig. 12 , are assigned reference signals of the first type. The control means 18 also communicate to at least one transmitting node 14 _y having at least two transmitting antennas 16 ₁₁ and 16 ₁₂ in at least one of the first time slot and the second time slot in the predefined bandwidth, in FIG. 12 being 14 ₁ , assign a second type of reference signal.

According to a preferred embodiment of the system 10 according to the invention, the control means 18 also assign to the first time slot a reference signal of the second type corresponding to at least one transmit antenna 16 ₁₁ and to the second time slot corresponding to the remaining transmit antennas 16 of ₁₂ reference signals of the second type.

According to another embodiment, in general, the wireless communication system 12 includes P scheduled user equipments 20 ₁ , . . . , 20 _P , where P is an integer, and P≧2. In Fig. 12, only _two scheduled user equipments ₂₀₁ and 202 are disclosed. The control means 18 also assigns to the _first time slot a second type of reference signal corresponding to at least one scheduled user equipment 201 . The control means 18 also assigns a second type of reference signal corresponding to the remaining scheduled user equipments 202 to the _second time slot.

According to another embodiment of the system 10, the control means 18 further assigns a reference signal of the second type corresponding to at least one first scheduled user equipment to the first time slot, and assigns a reference signal corresponding to at least one second scheduled user equipment to the second time slot. A second type of reference signal for the scheduled user equipment. The control means 18 also assigns to the first time slot a second type of reference signal corresponding to at least one transmit antenna of the at least one third scheduled user equipment, and assigns to the second time slot a reference signal corresponding to at least one third scheduled user equipment The second type of reference signal for the remaining transmit antennas.

Furthermore, according to another alternative, the control means 18 also assigns to the reference signal of the second type assigned to the first time slot a cyclic shift value different from that assigned to the reference signal of the second type assigned to the second time slot Rotate value.

According to another alternative, the control means 18 also assign to the reference signal of the second type a cyclic shift value equal to the cyclic shift value assigned to the reference signal of the second type assigned to the second time slot.

Furthermore, the first type of reference signal is a demodulation reference signal (DRS), and the second type of reference signal is a sounding reference signal (SRS).

Some computer program products 102 ₁ , . . . , 102 _n according to the present invention are schematically depicted in FIG. 13 . FIG. 13 shows n different digital computers 100 ₁ , . . . , 100 _n , where n is an integer. FIG. 13 shows n different computer program products 102 ₁ , . . . , 102 _n , here in the form of a CD. The different computer program products 102 ₁ , . . . , 102 _n can be loaded directly into the internal memories of n different computers 100 ₁ , . . . , 100 _n . Each computer program product 102 ₁ , . . . , 102 _n comprises software code portions for performing all steps according to FIG. 2 when the product 102 ₁ , . . . , 102 _{n is} run on a computer 100 ₁ , . For example, computer program products 102 ₁ , 102 _n may take the form of floppy disks, RAM disks, magnetic tape, magneto-optical disks, or some other suitable product.

The invention is not limited to the described embodiments. It will be apparent to a person skilled in the art that many different modifications are possible within the scope of the appended claims.

Claims (19)

1. a kind of method that antenna and node into wireless communication system assign reference signal, the method are characterized in that institute Stating reference signal, there are two types of different types, and the reference signal of the first kind is for demodulating, and the reference signal of Second Type is used for Measurement, and be the method includes：

To multiple transmitting nodes at least one transmitting antenna in the first time slot and the second time slot in predefined bandwidth Assign the reference signal of the first kind；And

To at least two hairs at least one of first time slot and second time slot in predefined bandwidth At least one transmitting node for penetrating antenna assigns the reference signal of the Second Type.

2. the method that the antenna and node according to claim 1 into wireless communication system assigns reference signal, special Sign is to assign the predefined bandwidth of the reference signal of the first kind and assigns the reference signal of the Second Type The predefined bandwidth it is equal.

3. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that

Correspond to the reference signal of the Second Type of at least one transmitting antenna to first timeslot assignments；And

Correspond to the reference signal of the Second Type of remaining transmitting antenna to second timeslot assignments.

4. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that

Correspond to the reference signal of the Second Type of at least one node to first timeslot assignments；And

Correspond to the reference signal of the Second Type of remaining node to second timeslot assignments.

5. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that

Correspond to the reference signal of the Second Type of at least one first node to first timeslot assignments；

Correspond to the reference signal of the Second Type of at least one second node to second timeslot assignments；And

Correspond to the Second Type of at least one transmitting antenna of at least one third node to first timeslot assignments The reference signal, and correspond to second timeslot assignments remaining described transmitting day of at least one third node The reference signal of the Second Type of line.

6. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that the reference signal for the Second Type for being assigned to first time slot and to when being assigned to described second The different cyclic shift value of the assignment of reference signals cyclic shift value of the Second Type of gap.

7. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that the reference signal for the Second Type for being assigned to first time slot and to when being assigned to described second The equal cyclic shift value of the assignment of reference signals cyclic shift value of the Second Type of gap.

8. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that the antenna is virtual-antenna, and is that the method also includes pre- to the application of each reference signal before transmission Encoder matrix or vector.

9. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, The reference signal for being characterized in that the first kind is demodulated reference signal DRS.

10. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that the reference signal of the Second Type is detection reference signal SRS.

11. the method that the antenna and node according to claim 1 or 2 into wireless communication system assigns reference signal, It is characterized in that the reference signal of the first kind is by pre-coding matrix or vector precoding, and the reference of Second Type Signal is not by pre-coding matrix or vector precoding.

12. a kind of system that antenna and node into wireless communication system assign reference signal, the system are characterized in that There are two types of different types for the reference signal, and the reference signal of the first kind is for demodulating, and the reference signal of Second Type is used In measurement, and be the system comprises：

Control device, in predefined bandwidth in the first slot and in the second time slot, to at least one transmitting day Multiple transmitting nodes of line assign the reference signal of the first kind；And

Control device, also in predefined bandwidth at least one of first time slot and second time slot, to The reference signal of the Second Type is assigned at least one transmitting node of at least two transmitting antennas.

13. the system that the antenna and node according to claim 12 into wireless communication system assigns reference signal, It is characterized in that the control device assigns the reference of the first kind and the Second Type to believe in identical predefined bandwidth Number.

14. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that

The control device corresponds to first timeslot assignments described in the Second Type of at least one transmitting antenna Reference signal；And

The control device corresponds to second timeslot assignments described in the Second Type of remaining transmitting antenna Reference signal.

15. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that

The wireless communication system includes P scheduled nodes, and wherein P is integer, and P >=2, and the control device is to described the One timeslot assignments correspond to the reference signal of the Second Type of at least one scheduled node；And

The control device corresponds to the institute of the Second Type of remaining scheduled node to second timeslot assignments State reference signal.

16. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that the reference signal from the control device to the Second Type for being assigned to first time slot with to It is assigned to the different cyclic shift value of the assignment of reference signals cyclic shift value of the Second Type of second time slot.

17. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that the reference signal from the control device to the Second Type with to being assigned to second time slot The equal cyclic shift value of the assignment of reference signals cyclic shift value of the Second Type.

18. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that the reference signal of the first kind is demodulated reference signal DRS.

19. what the antenna and node according to claim 12 or 13 into wireless communication system assigned reference signal is System, it is characterised in that the reference signal of the Second Type is detection reference signal SRS.