WO2010102455A1

WO2010102455A1 - Indication method and base station for sdma transmission

Info

Publication number: WO2010102455A1
Application number: PCT/CN2009/070788
Authority: WO
Inventors: 李元杰
Original assignee: 深圳华为通信技术有限公司
Priority date: 2009-03-13
Filing date: 2009-03-13
Publication date: 2010-09-16
Also published as: CN102077658A; CN102077658B

Abstract

An indication method and a base station for Space Division Multiple Access (SDMA) transmission are provided, the method comprises: when the SDMA transmission is adopted in the Long Term Evolution (LTE) system, the power allocation information is disposed in the Downlink Control Information (DCI), so as to indicate the terminal to perform demodulation based on the power allocation information (11); the DCI containing the power allocation information is transmitted to the terminal (12). The base station comprises a disposing module and a transmission module, or only comprises a transmission module. The above-mentioned technical proposal allows the terminals which use different beam for transmission to acquire respective power allocation information by means of disposing power allocation information in the transmission signal, consequently the indication for SDMA transmission is realized, the space division multiplex technique that plurality of users multiplexing one and the same time-frequent resource is supported, and the utilization ratio is effectively enhanced.

Description

Method and base station for indicating spatial division multiple access transmission

The present invention relates to the field of communications technologies, and in particular, to an indication method and a base station for space division multiple access transmission. Background technique

Long Term Evolution (LTE) is an evolution technology of the 3rd Generation Partnership Project (3GPP), which improves and enhances the 3GPP's air access technology. LTE uses Orthogonal Frequency Division Multiplexing (OFDM) and Multiple Input Multiple Output (MIMO) as its core air interface technology for wireless network evolution. It can provide downlink 100Mbps and 20MHz spectrum bandwidth. The uplink peak rate of 50Mbps improves the cell capacity and reduces the system delay.

MIMO is an advanced multi-antenna technology in wireless communication systems that independently transmits signals by using multiple antennas at the transmitting end, and simultaneously receives information with multiple antennas at the receiving end. MIMO mainly utilizes the spatial freedom provided by multiple transmit antennas and multiple receive antennas to effectively improve the spectrum efficiency of the wireless communication system, thereby improving the transmission rate and improving the signal quality, without increasing the system bandwidth or the total transmit power. Significantly increase the throughput and transmission distance of the system.

In addition, the LTE protocol also supports another advanced multi-antenna technology, namely beamforming. Beamforming forms an antenna array through multiple antenna elements to obtain array gain by using beamforming techniques. The transmitted or received signal gives a certain feature weight to beamform the signals on the multiple antenna elements, so that the transmitted or received signals have obvious directional characteristics, which can effectively enhance the useful signal to suppress interference and improve the signal. Noise ratio.

When LTE base stations, ie, evolved Node Bs (eNodeBs) support multiple antenna arrays, MIMO can be used in combination with Beamforming. That is, each antenna array is used Beamforming technology, and MIMO technology is used between multiple antenna arrays. Here, MIMO technology includes transmit diversity and space division multiplexing. For example, physical antennas (PAs) are grouped, and each group of PAs corresponds to one virtual antenna (Virtual Antenna). Each transport layer is mapped to a subset of the physical antennas through a mapping module of virtual antenna-physical antennas and shaped separately. In this way, different physical antenna subsets form different beams for transmitting different layers, thereby implementing space division multiplexing.

Multiple beams formed can be allocated to different users. This is called Space Division Multiple Access (SDMA) transmission. Each user uses one or more beams, due to low interference between beams. In this way, Beamforming's array gain can be used to improve the signal-to-noise ratio of the signal to reduce interference between users, and MIMO technology can be used to further provide the channel capacity of the system, improve spectrum utilization efficiency, and have good practical value.

When the eNodeB uses the above technology to transmit signals, it needs to send relevant information to the terminal to instruct the terminal to correctly receive and demodulate the data signal.

In the prior art, when the eNodeB uses Beamforming to transmit signals, the downlink control signal (DCI) is used to instruct the terminal to perform reception and demodulation on the data signals. The indication method includes: using a DCI format 1A signaling, a resource allocation indication, a coded modulation mode indication, a hybrid automatic repeat request (HQQ) process number, a new data indication, and an uplink physical control channel ( The physical uplink control channel (PUCCH), the power indication, the redundancy version indication, and the Cyclical Redundancy Check (CRC) are transmitted to the terminal, so that the terminal can correctly receive the data signal according to the related information. Tune.

In the process of implementing the present invention, the inventors have found that the downlink control signaling DCI format 1A in the prior art only supports Beamforming transmission of a single user, and cannot support multiple user-multiplexed SDMA transmissions. Therefore, there is an urgent need in the LTE system for an indication that the technology implements SDMA transmission. Summary of the invention

Embodiments of the present invention provide an indication method and a base station for space division multiple access transmission to implement SDMA Instructions for transmission.

An embodiment of the present invention provides a method for indicating a space division multiple access transmission, including:

When the space division multiple access transmission is used in the long term evolution system, the power allocation information is set in the downlink control signaling, so as to instruct the terminal to perform demodulation according to the power allocation information;

Sending downlink control signaling including the power allocation information to the terminal.

An embodiment of the present invention further provides an indication method for space division multiple access transmission, including:

When the space division multiple access transmission is used in the long term evolution system, the downlink control signaling is sent to the terminal, so that the terminal is instructed to perform demodulation according to the power allocation information; the downlink control signaling does not include a codebook indication field, The rest is the same as the downlink control signaling format 1D.

The embodiment of the invention further provides a base station, including:

a setting module, configured to: when the spatial division multiple access transmission signal is used in the long term evolution system, set the power allocation information in the downlink control signaling, so as to instruct the terminal to perform demodulation according to the power allocation information;

And a sending module, configured to send downlink control signaling that includes the power allocation information to the terminal. The embodiment of the present invention further provides a base station, including: a sending module, configured to send downlink control signaling to a terminal when the space division multiple access transmission is used in the long term evolution system, to indicate that the terminal allocates according to the power The information is demodulated; the downlink control signaling does not include a codebook indication, and the rest is the same as the downlink control signaling format 1D.

The foregoing technical solution can obtain the power allocation information of the respective signals by using the power allocation information in the transmission signal, so that the power allocation information of the respective signals can be obtained, thereby realizing the indication of the SDMA transmission, and supporting multiple users to multiplex the same time-frequency resources. Space division multiplexing technology effectively improves spectrum utilization. DRAWINGS

FIG. 1 is a flowchart of a method for indicating a spatial division multiple access transmission according to an embodiment of the present invention; FIG. 2 is a schematic structural diagram of a base station according to an embodiment of the present invention. detailed description

The technical solutions of the embodiments of the present invention are further described in detail below.

FIG. 1 is a flowchart of a method for indicating spatial division multiple access transmission according to an embodiment of the present invention. The method includes:

Step 11. When the LTE system uses the SDMA transmission signal, the eNodeB sets the power allocation information in the DCI, so as to instruct the terminal to perform demodulation according to the power allocation information.

Step 12. Send a DCI containing power allocation information to the terminal. In this way, after receiving the DCI, the terminal can demodulate according to the power allocation information in the DCI.

Since the transmit power of the eNodeB is limited, when multiple SDMA transmissions are used, multiple multiplexed users will use the same time-frequency resources, which requires the eNodeB to perform power allocation among these multiplexed users. The power allocation information is notified to the terminal through control signaling. Therefore, in this embodiment, when the LTE system uses the SDMA transmission signal, the eNodeB transmits power allocation information to the terminal for power allocated by multiple users that simultaneously transmit signals using different beams, so that each user can allocate power according to the power. The information is demodulated, and each user can correctly receive and demodulate the data signal, which satisfies the requirement that multiple users use different beams for simultaneous transmission.

In the above step 11, setting the power allocation information in the DCI may include: setting power allocation information in the DCI. One or two bits are set in the DCI to indicate power allocation information. .

In another indication method for spatial division multiple access transmission in the embodiment of the present invention, power information allocated to the terminal may be indicated by designing a new DCI format. One of the ways is to modify the existing DCI format 1A to indicate the power information allocated to the terminal when using the space division multiplexing transmission mode. An example of the information contained in a modified DCI is as follows:

a power allocation information indication field (indicating power allocation information with a number of bits);

Resource allocation indication field (not limited);

Coded modulation mode indication field (not limited);

HARQ process number field (not limited); New data indication field (not limited);

PUCCH power indication field (not limited);

Redundancy version indication field (not limited);

CRC check field (not limited).

In this embodiment, a bit is added as a power allocation information indication field by adding 1 bit to the existing DCI format 1A. The different states of the field indicate that the transmit power is divided into several equal parts, for example, the state '0' indicates that the power is constant, and the state T indicates that the power is reduced by half, which means that the power is reduced by 3 decibels (dB). Other bits are not limited and can retain the meaning and rules defined by the existing DCI format 1A.

In this embodiment, when a plurality of users belong to the SDMA transmission, the transmission power of the eNodeB can be indicated in this manner when the users perform equal power allocation.

In another indication method for space division multiple access transmission in the embodiment of the present invention, the power information allocated to the terminal when the space division multiplexing transmission mode is used is still indicated by the modification of the existing DCI format 1A. An example of the information that a modified DCI contains is as follows:

Resource allocation indication field (not limited);

Coded modulation mode indication field (not limited);

HARQ process number field (not limited);

New data indication field (not limited);

PUCCH power indication field (not limited);

Redundancy version indication field (not limited);

CRC data field (not limited).

In this embodiment, the quantization level of the power allocation can be established by adding 2 or more bits in the existing DCI format 1A as the power allocation information indication field. The different states of this field indicate how much power is allocated. The bits of other fields are not limited, and the original meaning and rules are maintained. For example, 2 bits are used as the power allocation information indication field (not limited to these indication methods): Field value power allocation information

00 full power

01 1/4 full power

10 1/2 full power

11 3/4 full power

Assuming that terminal A, terminal B, and terminal C transmit signals simultaneously using different beams, the power allocated by the eNodeB to user A, terminal B, and terminal C is 1/4 full power, 1/4 full power, and 1/2 full power, respectively. The eNodeB sets the value of the resource allocation indication field in the DCI sent to the terminal A and the terminal B to "01", and sets the value of the resource allocation indication field to "10" in the DCI sent to the terminal C. In this way, terminal A, terminal B, and terminal C can obtain respective power allocation information according to the value of the resource allocation indication field in the received DCI, and then demodulate according to the obtained power allocation information, thereby achieving correct demodulation.

As another example, 3 bits are used as the power allocation information indication field:

In this embodiment, when the indication is performed in this manner, the power allocation among the plurality of users belonging to the SDMA transmission may be unequal, and the allocation may be performed according to the channel condition of each user. Assuming that the channel quality of the user closer to the base station is better than the channel quality of the user farther from the base station, the power allocated to the user with good channel quality can be less, and the power allocated to the user with poor channel quality is more. Some, so more flexible and efficient use of time-frequency resources.

Alternatively, in step 11 above, setting the power allocation information in the DCI may include: masking the cyclic redundancy code check data in the DCI with a mask indicating the power allocation information. Thus, when the terminal receives the DCI with the power allocation information masked, the allocated power information can be known and demodulated according to the allocated power information.

In the method for indicating the spatial division multiple access transmission in the embodiment of the present invention, the power allocation of the eNodeB can be represented by masking the CRC of the existing DCI format 1A.

In wireless communication, in order to prevent erroneous reception of data, it is generally necessary for the transmitting end to CRC encode the data with CRC data, and to add the CRC data to the CRC data field of the control command. If an error occurs in the data received by the receiving end, the CRC check cannot be passed.

In this embodiment, the power allocation information of the eNodeB is represented by masking the CRC data of the existing DCI format 1A. For example, when the eNodeB does not perform power allocation, the CRC data is not masked; when the eNodeB performs power allocation to the User Equipment (UE), the CRC data line is masked with a specific sequence, that is, a mask. Among them, a specific sequence, that is, a mask, is used to indicate power allocation information, that is, a case indicating power allocation. For example, the length of the CRC data is 24, which is expressed as CRC(24), and the sequence length of the mask is also 24, which is expressed as Mask(24). The process of masking at the transmitting end includes:

CRC_Mask(24) = (CRC(24)+Mask(24)) mod 2;

Among them, CRC_Mask (24) represents the masked CRC data, and mod is the modulo operation. When the data transmission is correct, the receiving end should correctly verify the data, and the CRC-Mask (24;> needs to be masked, which can be expressed as:

CRC(24) = (CRC_Mask(24)+Mask(24)) mod 2;

The receiving end, that is, the UE, matches the received CRC_Mask (24) by using the possible Mask (24) sequence. If the matching is performed, the mask (24) sequence is the power allocation information, thereby obtaining the power allocation information of the received data. And then obtaining data points that should be demodulated for demodulation.

In this embodiment, the method is used to indicate the use of the existing DCI format 1 A format. Implementation, without adding a new control signaling format, thereby reducing the amount of data transmission and reducing the channel load. The method for indicating the spatial division multiple access transmission in the embodiment of the present invention includes: when the SDMA transmission is used in the LTE system, the DCI is sent to the terminal, so that the terminal is instructed to perform demodulation according to the power allocation information; The DCI does not contain a codebook indication, and the rest is the same as the DCI format 1D. The DCI in this embodiment can be implemented by improving the existing DCI format 1D signaling. For example, deleting a new DCI formed after the codebook indication in the existing DCI format ID can implement an indication of SDMA transmission. The new DCI can contain the following information:

Power allocation information indication (indicating power allocation information with several bits);

Resource allocation indication (not limited);

Code modulation mode indication (not limited);

Number of HARQ processes (not limited);

New data indication field (not limited);

Power indication of PUCCH (not limited);

Redundancy version indication (not limited);

CRC data (not limited).

At this time, the manner in which the terminal acquires the channel information may be the same as the manner in which the terminal acquires the channel information in the beamforming transmission mode in the prior art.

FIG. 2 is a schematic structural diagram of a base station according to an embodiment of the present invention. The base station can be an eNodeB, including: a setup module 21 and a transmit module 22. In the case where the eNodeB uses the SDMA transmission signal, the setting module 21 sets the power allocation information in the DCI to instruct the terminal to perform demodulation according to the power allocation information; the transmitting module 22 transmits the DCI including the power allocation information to the terminal. After receiving the DCI, the terminal can demodulate according to the power allocation information in the DCI.

In this embodiment, the eNodeB sets the power allocation information in the DCI through the setting module 21, and transmits the power to the DCI through the setting module 21, in the case of using the SDMA transmission signal, for the power allocated by multiple users simultaneously transmitting signals with different beams. 22, the power allocation information is sent to the terminal, so that each user can perform demodulation according to the power allocation information, so that each user performs the data signal Correct reception and demodulation meets the need for multiple users to transmit simultaneously using different beams. In another base station in the embodiment of the present invention, the setting module may be specifically used to add a bit in the DCI; for example, adding a bit for indicating power allocation information in the DCI format 1A, as described in the foregoing method embodiment.

In another base station in the embodiment of the present invention, the setting module may be specifically configured to mask the CRC data in the DCI by using a mask indicating power allocation information; and replace the masked CRC data in the DCI format 1A. CRC data. Thus, when the terminal receives the DCI with the power allocation information masked, the allocated power information can be learned and demodulated according to the allocated power information. The specific manner of masking power allocation information is described in the above method embodiment.

Yet another base station in the embodiment of the present invention includes a transmitting module. The sending module is configured to send a DCI to the terminal when the SDMA transmission is used in the LTE system, to instruct the terminal to perform demodulation according to the power allocation information; the DCI does not include a codebook indication, and the rest is the same as the DCI format 1D. . The DCI may be obtained by deleting a codebook indication in the DCI format ID, and performing DCD transmission for SDMA transmission to implement an indication of SDMA transmission.

The foregoing method and the base station embodiment solve the problem that the downlink control signaling format defined in the existing protocol can only support one Beamforming array by expanding the existing 3GPP LTE protocol.

UE, fully exploited the advantages of multi-antenna technology.

A person skilled in the art can understand that all or part of the steps of implementing the above method embodiments may be completed by using hardware related to program instructions, and the foregoing program may be stored in a computer readable storage medium, and the program is executed when executed. The foregoing steps include the steps of the foregoing method embodiments; and the foregoing storage medium includes: a medium that can store program codes, such as a ROM, a RAM, a magnetic disk, or an optical disk.

It should be noted that the above embodiments are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those skilled in the art that: The technical solutions described in the foregoing embodiments are modified, or some of the technical features are equivalently replaced. The modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

Rights request

A method for indicating a space division multiple access transmission, comprising:

2. The method for indicating a spatial division multiple access transmission according to claim 1, wherein the setting the power allocation information in the downlink control signaling comprises:

One or more bits are set in the downlink control signaling to indicate power allocation information.

The method for indicating a spatial division multiple access transmission according to claim 1 or 2, wherein the downlink control signaling specifically includes: a resource allocation indication field, a coded modulation mode indication field, and a hybrid automatic repeat request process. A digital segment, a new data indication field, a power indication field of an uplink physical control channel, a redundancy version indication field, a cyclic redundancy check data field, and a power allocation information indication field indicating the power allocation information.

The method for indicating a spatial division multiple access transmission according to claim 1, wherein the setting the power allocation information in the downlink control signaling comprises:

The cyclic redundancy code check data in the downlink control signaling is masked with a mask indicating power allocation information.

5. A method for indicating a space division multiple access transmission, comprising:

6. A base station, comprising:

a setting module, configured to set power allocation information in the downlink control signaling when the spatial division multiple access transmission signal is used in the long term evolution system, to instruct the terminal to perform solution according to the power allocation information And a sending module, configured to send downlink control signaling that includes the power allocation information to the terminal.

The base station according to claim 6, wherein the setting module is specifically configured to set one or more bits in the downlink control signaling to indicate power allocation information.

The base station according to claim 6 or 7, wherein the downlink control signaling specifically includes: a resource allocation indication field, a coded modulation mode indication field, a hybrid automatic repeat request process number field, and a new data indication field. And a power indication field of the uplink physical control channel, a redundancy version indication field, a cyclic redundancy code check data field, and a power allocation information indication field including power allocation information.

The base station according to claim 6, wherein the setting module is specifically configured to perform power masking on the cyclic redundancy code check data in the downlink control signaling by using a mask indicating power allocation information. .

10. A base station, comprising:

a sending module, configured to send downlink control signaling to the terminal when the space division multiple access transmission is used in the long term evolution system, to indicate that the terminal performs demodulation according to the power allocation information; the downlink control signaling does not include The codebook indicates that the rest is the same as the downlink control signaling format 1D.