Sending method and device for rank instructional information

TECHNICAL FIELD The present invention relates to the field of communications, and in particular, to a method and device for sending rank indication information.

BACKGROUND Multiple-input multiple-output (Multiple-Input Multiple-Out-put, referred to as MIMO) technology is the key technology of the third generation (3G) and fourth generation (4G) mobile communication systems, which can increase system capacity and improve Transmission performance, and can be well integrated with other physical layer technologies, but when the channel correlation is strong, the diversity gain and multiplexing gain brought by the multipath channel will be greatly reduced, resulting in a significant drop in the performance of the MIMO system . At present, a new MIMO precoding method is proposed. This method is an efficient MIMO multiplexing method. The MIMO channel is divided into multiple independent virtual channels through the precoding processing at the transceiver end, which effectively eliminates the problem of channel correlation. Therefore, the precoding technology ensures the stability of the MIMO system in various environments.

The Long Term Evolution (LTE for short) system is an important plan of the third-generation partner organization. The precoding technology is implemented in LTE by setting codes in the user equipment (UE) and base station (eNodeB). In this (precoding matrix set), the UE selects the best precoding matrix from the codebook according to certain criteria (for example, the maximum throughput or the right singular matrix closest to the channel matrix), and the index of the precoding matrix (Precoding Matrix Index (referred to as PMI) is fed back to the eNodeB. The eNodeB searches for the corresponding precoding matrix in the codebook according to the received PMI, and applies this precoding matrix for precoding transmission in downlink transmission.

200810142974.8 The rank indicator (RI) information is fed back in the uplink channel. The RI information indicates the maximum number of symbols that can be transmitted on a subcarrier.

Figure 1 shows a schematic structural diagram of the basic frame structure in the LTE system. As shown in Figure 1, the frame structure is divided into four levels: radio frame, half frame, subframe, time slot, and symbol. The length of a radio frame is 10ms, a radio frame is composed of two half-frames, each half-frame is 5ms in length, a half-frame is composed of 5 sub-frames, each sub-frame is 1ms in length, and a sub-frame is composed of two time slots, each The length of the time slot is 0.5mSo. When the LTE system adopts the conventional cyclic prefix, a time slot contains 7 uplink/downlink symbols with a length of 66.7us. Among them, the cyclic prefix length of the first symbol is 5.21us, and the other 6 symbols The cyclic prefix length is 4.69us» When the LTE system adopts the extended cyclic prefix, a slot contains 6 uplink/downlink symbols with a length of 66.7us, and the cyclic prefix length of each symbol is 16.67us.

A resource element (Resource Element, referred to as RE) is a subcarrier in an orthogonal frequency division multiplexing (Orthogonal frequency Division Multiplexing, referred to as OFDM) symbol, and a downlink resource block (Resource Block, referred to as RB) consists of Consecutive 12 subcarriers and continuous 7 OFDM symbols (6 OFDM symbols for long CP) are composed of 180kHz in the frequency domain and the time length of a general time slot in the time domain. Figure 2 shows the LTE system A schematic diagram of the structure of a resource block with a medium bandwidth of 5 MHz, as shown in FIG. 2, during resource allocation, the resource block is used as the basic unit for allocation.

When the target user feeds back RI information, if the target user does not need to send data, the RI information is transmitted in the Physical Uplink Control Channel (PUCCH). If the target user needs to send data, the RI information is Transmission in Physical Uplink Shared Channel (PUSCH for short).

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The PUCCH format is divided into six types: format 1, format la, format lb and format 2, format 2a, and format 2b. Among them, format 1 is used to transmit 1-bit Scheduling Request (SR) information, indicating that there is or No SR, format la is used to transmit ACK/NACK (Acknowledgement/Negative Acknowledgement) information of a 1-bit single codeword stream, format 1 b is used to transmit ACK/NACK information of a 2-bit dual codeword stream, where each codeword stream Corresponding to 1-bit ACK/NACK information, format 2 is used to transmit Channel Quality Indicator (CQI)/PMI and RI information, and format 2a is used to transmit CQI/PMI and RI information, single codeword stream ACK/ NACK information, format 2b is used to transmit CQI/PMI and RI information, dual codeword stream ACK/NACK information, format 2a and format 2b are used in scenarios where the cyclic prefix is a regular cyclic prefix; Figure 3 shows the physical uplink in the LTE system A schematic diagram of the frequency domain position of the control channel, as shown in Figure 3, each PUCCH channel occupies the resources of two resource blocks; the length of the RI information is 1 bit or 2 bits, and when the RI information and the CQI/PMI information are in the same subframe When sending in medium, only RI information is sent.

The following describes the channel structure of PUCCH format 2: Figure 4 shows a schematic diagram of the PUCCH channel used to transmit RI information when the system uses a conventional cyclic prefix. As shown in Figure 4, in the conventional cyclic prefix, the length is selected as The 12 CAZAC sequence is used as the basic sequence. The CAZAC sequence will be repeated 7 times. Each symbol of a resource block is mapped to a CAZAC sequence at 12 frequency domain positions. Among them, time slots #0, #2, #3 The sequences on the symbols #4 and #6 are used for data transmission on the PUCCH channel, and the sequences on the symbols of time slots #1 and #5 are used for the transmission of a reference signal (Reference Signal, referred to as RS) on the PUCCH channel.

Figure 5 shows a schematic diagram of the PUCCH channel used to transmit RI information when the system adopts an extended cyclic prefix. As shown in Figure 5, in the extended cyclic prefix, a CAZAC sequence with a length of 12 is selected as the basic sequence, and the CAZAC The sequence is repeated 6 times, and one resource block is mapped to each of the 12 frequency domain positions on each symbol

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CAZAC sequence, where the sequence on the symbols of time slots #0, #1, #2, #4, and #5 are used for data transmission on the PUCCH channel, and the sequence on the symbols of time slot #3 is used for the PUCCH channel Reference signal transmission.

The number of bits of the encoded CQI/PMI and RI information is 20, and the number of encoded bits is subjected to quadrature phase shift keying (QPSK) modulation, modulated into 10 QPSK modulation symbols, and 5 QPSK modulations are mapped on each time slot Symbol, and let each modulation symbol correspond to a PUCCH channel data sequence, multiply the modulation symbol with the target data sequence, map it to the corresponding carrier and send it out. Among them, the channel measurement reference signal (Sounding Reference Signal, Sounding RS SRS for short) is sent on the last symbol of a subframe.

In the LTE system, the transmission of uplink data adopts the single-carrier frequency division multiple access (SC-FDMA) method, which requires continuous mapping of uplink resources, and all the data to be sent on each symbol needs to be modulated. The Fourier Transform (Discrete Fourier Transform, referred to as DFT) is processed and mapped to the frequency domain position. If the PUCCH channel and the channel measurement reference signal are sent on the same symbol, it will cause inter-code crosstalk, and the code between PUCCH channels cannot be guaranteed. Orthogonality leads to system performance degradation.

In the LTE standard, when the uplink ACK/NACK information and the channel measurement reference signal are sent on the same symbol, the short code structure is used to send the uplink ACK/NACK information; when the CQI/PMI information and the channel measurement reference signal are on the same symbol When sending on the symbol, the short code structure is used to send the uplink ACK/NACK information; when the SR information and the channel measurement reference signal are sent on the same symbol, the SR information is sent on the symbol, and the channel measurement reference signal is not sent. Regarding the method in which the RI information and the channel measurement reference signal are sent in the same subframe, the prior art does not provide a specific solution.

200810142974.8 Summary of the Invention Considering the related art for sending RI information and channel measurement reference signals in the same subframe, the prior art does not provide a specific solution and proposes the present invention. For this reason, the main purpose of the present invention A method and device for sending rank indication information are provided to solve the above-mentioned problem.

According to one aspect of the present invention, a method for sending rank indication information is provided.

The method for sending rank indication information provided according to an embodiment of the present invention includes: when the rank indication information and the channel measurement reference signal are sent in the same subframe, the channel measurement reference signal is carried in the last symbol of the subframe; and the rank indication is sent Information and channel measurement reference signal.

Wherein, sending the rank indication information and the channel measurement reference signal is specifically: sending the channel measurement reference signal on the last symbol; sending the rank indication information on symbols other than the last symbol.

The structure of the subframe includes one of the following: a regular cyclic prefix subframe structure, and an extended cyclic prefix subframe structure.

According to one aspect of the present invention, a method for sending rank indication information is provided.

The method for sending rank indication information provided according to an embodiment of the present invention includes: when the rank indication information and the channel measurement reference signal are sent in the same subframe, only the rank indication information is sent.

According to another aspect of the present invention, a device for sending rank indication information is provided.

The apparatus for sending rank indication information provided according to an embodiment of the present invention includes: a bearer module, which is used for when the rank indication information and the channel measurement reference signal are sent in the same subframe,

200810142974.8 The channel measurement reference signal is carried in the last symbol of the subframe; the sending module is used to send the rank indication information and the channel measurement reference signal.

Through the above at least one technical solution of the present invention, the problem of orthogonality destruction of codes between PUCCH channels caused when RI information and channel measurement reference signals are sent on the same symbol is solved, and the overall performance of the system is guaranteed.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of them, which are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the drawings: Figure 1 is a schematic structural diagram of a basic frame structure in an LTE system according to a related technology; Figure 2 is a schematic structural diagram of a resource block with a bandwidth of 5 MHz in an LTE system according to a related technology; Figure 3 is an LTE system according to the related technology Schematic diagram of the frequency domain position of the physical uplink control channel in the relevant technology; Figure 4 is a schematic diagram of the PUCCH channel used to transmit RI information when the system according to the related technology uses a conventional cyclic prefix; A schematic diagram of a PUCCH channel for transmitting RI information; FIG. 6 is a flowchart of a method for sending rank indication information according to a method embodiment of the present invention; Schematic diagram of the structure of the PUCCH channel and channel measurement reference signal for transmitting RI information;

200810142974.8 Figure 8 is a schematic diagram of the structure of the PUCCH channel and channel measurement reference signal used to transmit RI information when the system adopts the extended cyclic prefix according to the method embodiment of the present invention; Figure 9 is the structure of the rank indication information according to the device embodiment of the present invention The structural frame diagram of the sending device.

DETAILED DESCRIPTION The present invention will be described in detail below in conjunction with the accompanying drawings.

Method embodiment According to an embodiment of the present invention, a method for sending rank indication information is provided.

Fig. 6 is a flowchart of a method for sending rank indication information according to an embodiment of the present invention. As shown in Fig. 6, the method includes the following steps: Step S602, when the rank indication (RI) information and the channel measurement reference signal (SRS) are When sending in the same subframe, the channel measurement reference signal is carried in the last symbol of the subframe; step S604, the RI information and the channel measurement reference signal are sent, specifically, the channel measurement reference signal is sent in the last symbol, except for the last symbol Symbols other than one symbol send RI information, that is, no sequence for transmitting RI information is sent in the last symbol.

The technical solution provided by the embodiment of the present invention solves the problem of the orthogonality destruction of codes between PUCCH channels caused when the RI information and the channel measurement reference signal are sent on the same symbol, and the overall performance of the system is guaranteed.

200810142974.8 According to an embodiment of the present invention, a method for sending rank indication information is also provided. In this method: when the rank indication information and the channel measurement reference signal are in the same subframe, only the rank indication information is sent.

Figure 2 shows a schematic diagram of the resource block structure of the 3GPP LTE system with a bandwidth of 5M. As shown in Figure 2, the system includes a total of 512 subcarriers, of which the available subcarriers are 300 in the middle, and each resource block includes With 12 consecutive subcarriers, the 3GPPLTE system with 5M bandwidth includes 25 resource blocks. If the number of available uplink resource blocks is N, all resource blocks are numbered 0, 1, 2 in the order of frequency domain from low to high. , N Yu-1, "PRB represents the index of the resource block, and the frequency domain position of the PUCCH channel numbered m is shown in FIG. 3. The following takes a 3GPP LTE system with a bandwidth of 5M as an example to describe the embodiments of the present invention in detail.

Case 1: When the target user sends information to the base station, when the PUCCH channel and the channel measurement reference signal that transmit the RI information are sent in the same subframe, the RI information can be sent in each symbol of the subframe without sending the channel Measure the reference signal.

The structure of the above-mentioned subframe may be a subframe structure of a regular cyclic prefix, or a subframe structure of an extended cyclic prefix. In view of this, the following two scenarios are used to describe.

Case 2: When the system adopts the conventional cyclic prefix subframe structure, if the PUCCH channel and the channel measurement reference signal for transmitting RI information are sent in the same subframe, the CAZAC sequence of length 12 searched by the computer can be selected, and the This CAZAC sequence serves as the basic sequence.

FIG. 7 shows a schematic diagram of the PUCCH channel structure of the method for sending rank indication information according to the method embodiment of the present invention. As shown in FIG. 7, the CAZAC sequence is repeated 7 times, and 12 on each symbol of a resource block Mapping a CAZAC on the frequency domain position

200810142974.8 The first sequence, where the sequence on the #0, #2, #3, #4, and #6 symbols of each slot is used to transmit the data of the PUCCH channel, and the sequence on the #1, #5 symbols of each slot The sequence is used to transmit the reference signal of the PUCCH channel and encode the RI information, where the encoded RI information is 20 bits, and the encoded RI information is QPSK modulated, which is modulated into 10 QPSK modulation symbols. Map 5 QPSK modulation symbols, and let each modulation symbol correspond to a PUCCH channel data sequence, multiply the modulation symbol with the target data sequence, and map the multiplied result to the corresponding carrier, and send it to the base station ; At the same time, the channel measurement reference signal is carried on the corresponding carrier of the last symbol of the subframe and sent to the base station, and the RI information carried on the last symbol is not sent.

Case 3: When the system adopts the subframe structure of the extended cyclic prefix, if the PUCCH channel and the channel measurement reference signal for transmitting RI information are sent in the same subframe, the CAZAC sequence of length 12 searched by the computer can be selected, and the This CAZAC sequence serves as the basic sequence.

As shown in Figure 8, the CAZAC sequence can be repeated 6 times, and a CAZAC sequence is mapped to 12 frequency domain positions on each symbol of a resource block. Among them, #0, #1, #2 of each slot The sequence on symbols #4, #5 is used to transmit PUCCH channel data, and the sequence on symbol #3 of each time slot is used to transmit the reference signal of the PUCCH channel, and the RI information is encoded. Among them, the encoded RI The information is 20bit, the encoded RI information is QPSK modulated, and modulated into 10 QPSK modulation symbols, each time slot is mapped with 5 QPSK modulation symbols, and each modulation symbol corresponds to a PUCCH channel data sequence, The modulation symbol is multiplied by the target data sequence, and the multiplied result is mapped to the corresponding carrier and sent to the base station.

200810142974.8 At the same time, the channel measurement reference signal is carried on the corresponding carrier of the last symbol of the subframe and sent to the base station, and the RI information carried on the last symbol is not sent.

Device Embodiment According to an embodiment of the present invention, a device for sending rank indication information is provided.

FIG. 9 shows a schematic diagram of an apparatus for sending rank indication information according to an embodiment of the present invention. As shown in FIG. 9, the apparatus includes: a bearer module 10 for sending rank indication information and channel measurement reference signals in the same subframe At this time, the channel measurement reference signal is carried in the last symbol of the subframe; the sending module 20 is used to send the rank indication information and the channel measurement reference signal, and this module can be connected to the bearing module 10» according to the rank provided by the embodiment of the present invention. The sending device of the indication information solves the problem of destroying the orthogonality of codes between PUCCH channels caused when the RI information and the channel measurement reference signal are sent on the same symbol, and ensures the overall performance of the system.

As described above, with the help of the method and/or device for sending rank indication information provided by the present invention, the orthogonality of codes between PUCCH channels caused by the transmission of RI information and channel measurement reference signals on the same symbol is solved. The problem of destruction, and to ensure the overall performance of the system.

The above are only preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

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