CN101789813B - Feedback method of channel quality information and terminal - Google Patents
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Abstract
The invention discloses a feedback method of channel quality information (CQI) and a terminal. In the method, the terminal feeds back CQI to the network side, wherein CQI comprises the wideband CQI index of the serving cell and the wideband differential CQI index offset level of each coordinating cell in a plurality of coordinating cells; and the wideband differential CQI index offset level of the coordinating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the coordinating cell. The technical scheme provided by the invention solves the problem that the overhead is high when the terminal feeds back CQI during CoMP transmission in the related art, thus further reducing the feedback overhead of the terminal.
Description
Technical Field
The present invention relates to the field of communications, and in particular, to a Channel Quality Information (CQI) feedback method and a terminal in a coordinated multi-point (CoMP) transmission technology.
Background
In order to provide a higher throughput rate and solve the inter-cell interference problem, a new-generation wireless communication system considers introducing a cooperative Multiple Input Multiple Output (MIMO) technology between network levels, where the new-generation wireless communication system may be Long-Term Evolution (LTE-advanced) advanced, International mobile telecommunications (IMT-advanced) advanced, and the like. In LTE-Advance, a CoMP transmission technology has been formally studied as an alternative technology. Because the antenna distances from the cell edge users to a plurality of adjacent cells are not different greatly, the transmitting antennas of the cells cooperate to realize higher capacity and reliable transmission of wireless links at the cell edge, and the problem of interference caused by the users at the cell edge can be completely eliminated.
The above coordinated multipoint transmission technology is characterized in that:
(1) a Mobile terminal (MS) is served by cooperation of multiple Base Stations (BS) on the same radio resource.
(2) Each BS may serve one or more MSs simultaneously on the same radio resources.
Currently, various views are proposed based on LTE R8 for CoMP. Among them, the CoMP cooperative transmission method based on the antenna port 5(antenna port 5) is widely applied because it is compatible with the LTE Release (abbreviated as R)8 user.
In LTE R8, aperiodic CQI feedback on antenna port 5 Physical Uplink Shared Channel (PUSCH) supports the following two modes: mode2-0, Mode 3-0, the periodic CQI feedback of the Physical Uplink Control Channel (PUCCH) supports the following two modes: model 1-0 and model 2-0.
The following describes the aperiodic CQI feedback Mode2-0 and Mode 3-0 on the PUSCH as follows:
(1) mode2-0 is subband feedback selected by a User Equipment (UE), and the UE selects M better subbands from N subbands with a size of k, where values of k and M are related to a downlink system bandwidth. Number N of sub bands consisting ofCalculation of where NRB DLIs the downlink system bandwidth. The UE feeds back an average CQI on the selected M sub-bands, and the CQI value reflects the CQI of all layers (regardless of a computed or fed back Rank Indicator (RI); UE reports a wideband (wideband) CQI at the same time; for the transmission mode of open-loop spatial multiplexing (i.e., mode 3), the UE feeds back CQI according to the reported RI, and for other transmission modes, the reporting situation is the same as the case where RI is 1. The CQI feedback overhead is:
4(wideband CQI)+2(subband differential CQI)+L(Positionof the M selected subband)bits
specifically, 4bits are used to transmit the wideband CQI index, 2bits are used to transmit the sub-differential CQI index, and L bits are used to transmit the Position of the Mselected sub-.
(2) Mode 3-0 is subband feedback configured by a high layer, UE reports a Wideband CQI, UE reports the subband CQI for each subband (assuming that transmission is performed on the subband configured by the high layer), and the Wideband and subband CQI represents the channel quality of a first coded Codeword stream, and the method is also suitable for the case that RI is greater than 1; the subband differential CQI offset level is a subband CQI index-wideband CQI index, and the CQI feedback overhead is:
4(wideband CQI)+2N(subband differential CQI)bits
specifically, 4bits are used for transmitting the wideband CQI index, and 2N bits are used for transmitting the sub-band differential CQI index.
The periodic CQI feedback modes 1-0 and 2-0 on the PUCCH are described as follows:
(1) mode 1-0 is feedback of wideband, for the transmission Mode of Mode 3, in a subframe (subframe) reported by an RI, a UE determines an RI on a subframe set S, and reports according to type 3, including an RI; and in the subframe for reporting the CQI, the UE reports a wideband CQI, and assuming that the CQI is transmitted on a subframe set S, for the transmission of mode 3, the CQI is calculated according to the RI reported periodically at the last time, and for other transmission modes, the CQI is calculated according to the RI of 1. The CQI feedback overhead is:
4(wideband CQI) bits, i.e., 4bits, are used for transmitting the wideband CQI.
(2) Mode2-0 is feedback of UE selecting subband, for the transmission of Mode 3, in subframe reported by RI, UE determines an RI on subband set S, and UE reports according to type 3, including an RI; reporting CQIThe UE reports according to type 4, and feeds back a wideband CQI according to the last periodic RI report; reporting subframe by UE in each N of J bandwidth fragments when selecting subframe CQIjselecting a better sub-band by the sub-band set, reporting a CQI (channel quality indicator) including labels of L bits by the UE according to the selected sub-band according to type1, and sequentially performing type1 reporting on each bandwidth fragment at respective continuous reporting opportunities, wherein the CQI represents the channel quality on all layers, and the RI is not considered; for mode 3 transmission, the selection of subband and the calculation of CQI are better, depending on the RI reported last time, and for other transmission modes, RI is 1. The CQI feedback overhead is:
4(wideband CQI)bits
4(subband CQI) +1 or 2 (subband)
Specifically, 4bits are used for transmitting the wideband CQI index, and 1bit or 2bits are used for transmitting the sub band.
In coordinated multipoint CoMP, if a terminal takes an aperiodic mode 3-0 as an example according to an existing feedback mode, the feedback overhead is as follows:
wherein, B is the number of cells (including the serving cell) for cooperative transmission,the number of subbands of the serving cell,the number of subbands of each cooperative cell. As can be seen from the above equation, the feedback overhead increases linearly as the number of cooperating cells increases.
As can be seen from the above description, in CoMP transmission, the overhead of the terminal for CQI feedback is relatively large.
Disclosure of Invention
The present invention is proposed to solve the problem of relatively large overhead when the terminal performs CQI feedback during CoMP transmission in the related art, and therefore, a main object of the present invention is to provide an improved CQI feedback scheme to solve at least one of the above problems.
According to one aspect of the invention, a channel quality information feedback method is provided.
The channel quality information feedback method according to the present invention includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each of the plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
According to another aspect provided by the invention, a channel quality information feedback method is also provided.
The channel quality information feedback method according to the present invention includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the method comprises the steps of obtaining a CQI index differential offset level on each sub-band of a serving cell and a CQI index differential offset level on each sub-band of a plurality of cooperative cells, wherein the sub-band CQI index differential offset level of the serving cell is obtained by subtracting a broadband CQI index of the serving cell from each sub-band CQI index of the serving cell, and the sub-band CQI index differential offset level of the cooperative cells is obtained by subtracting the broadband CQI index of the serving cell from the sub-band CQI index of the cooperative cell.
According to another aspect provided by the invention, a channel quality information feedback method is also provided.
The channel quality information feedback method according to the present invention includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the terminal comprises a broadband CQI index of a serving cell, a broadband CQI index differential offset level of each cooperative cell in a plurality of cooperative cells, an average CQI index differential offset level of a plurality of sub-bands in the serving cell selected by the terminal and the plurality of cooperative cells, wherein the broadband CQI index differential offset level of the cooperative cells is obtained by subtracting the broadband CQI index of the cooperative cell from the broadband CQI index of the serving cell, and the average CQI index differential offset level of the plurality of sub-bands is obtained by subtracting the broadband CQI index of the serving cell from the average CQI index of the plurality of sub-bands.
According to still another aspect provided by the invention, a channel quality information feedback terminal is also provided.
The channel quality information feedback terminal according to the present invention includes: the device comprises a receiving module, a determining module, a feedback module and a calling module. The receiving module is used for receiving downlink control information from a network side, wherein the downlink control information is used for indicating a feedback mode of non-periodic CQI feedback by a terminal; the determining module is used for determining a feedback mode of the terminal for CQI feedback according to the downlink control information received by the receiving module; the feedback module is used for feeding back CQI information to the network side according to the feedback mode determined by the determination module, wherein the CQI information comprises: a wideband CQI index and/or a sub-band CQI index, a wideband CQI index differential offset level and/or a sub-band CQI index differential offset level; and the calling module is used for calling the feedback module to feed back according to the feedback mode determined by the determining module.
According to the invention, the method that the feedback information comprises the redefined CQI index differential offset grade when the terminal performs the CQI feedback is adopted, so that the problem that the overhead of the terminal during the CQI feedback is large during CoMP transmission in the related technology is solved, and the feedback overhead of the terminal is further reduced.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings:
fig. 1 is a schematic diagram of wideband CQI feedback in CoMP according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a cooperative cell sub-band CQI index difference relationship in CoMP according to an embodiment of the present invention;
figure 3 is a schematic diagram of sub-band CQI feedback in CoMP according to an embodiment of the invention;
fig. 4 is a block diagram of a terminal according to an embodiment of the present invention.
Detailed Description
Overview of the function
In consideration of the problem that overhead is large when the terminal performs CQI feedback during CoMP transmission in the related art, the embodiment of the present invention provides an improved CQI feedback scheme, where when the terminal performs CQI feedback, the feedback information includes a redefined CQI index differential offset level, and three feedback modes, that is, wideband CQI feedback according to an indication of a network side, sub-band CQI feedback according to an indication of the network side, and sub-band CQI feedback selected by the terminal for feedback, are described in detail below.
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
In CoMP, the pilot frequency of each Cell participating in the cooperation is designed orthogonally, the serving Cell can notify the terminal of the Cell identity (Cell ID) of each cooperating Cell, and the terminal can measure the channel information from each cooperating Cell to the terminal, at this time, the LTE-a terminal can obtain the wideband CQI of each cooperating Cell and the CQI information of each cooperating Cell, assuming that there are B cells performing cooperative transmission (B includes the serving Cell), and the number of the serving cells is equal toThe number of each cooperative cell is respectively
Method embodiment
Example one
According to an embodiment of the present invention, a CQI feedback method is provided, which is applied to a terminal for wideband CQI feedback, where a serving cell of the terminal performs cooperative transmission with multiple cooperative cells, and the method includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the method includes the steps of determining a wideband CQI index of a serving cell and a wideband CQI index differential offset level of each of a plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
With the embodiment, the overhead used by the wideband CQI index differential offset level of each cooperative cell is 3 bits.
Specifically, the wideband CQI index of each cooperative cell is fed back differentially, and the offset table of differential feedback can continue to use the condition of two CW transmissions of a single cell, ScellDenotes the serving cell, CcellIndicating a coordinated cell, the wideband CQI differential offset level in CoMP is defined as:
b th Ccell wideband CQI offset level＝Scellwideband CQI index-b-th Ccell wideband CQI index
The wideband CQI differential offset level in CoMP is obtained by differentiating the wideband CQI index of the serving cell and the wideband CQI index of each cooperative cell respectively, the terminal feeds back the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each cooperative cell, and the wideband CQI feedback overhead is as follows:
4(Scell wideband CQI)+3*(B-1)
wherein 3 is C (B-1)cellThe wideband CQI feedback overhead and the wideband differential offset level table may follow the existing wideband differential offset level table or may be redefined.
Fig. 1 is a schematic diagram of wideband CQI feedback in CoMP according to an embodiment of the present invention, as shown in fig. 1, the serving cell wideband CQI occupies 4bits, and each cooperative cell wideband differential CQI occupies 3bits, where the cooperative cell includes: a cooperative cell 1, a cooperative cell 2.
By the embodiment, the feedback overhead of the terminal is reduced when the wideband CQI is fed back in the CoMP.
Example two
According to an embodiment of the present invention, a CQI feedback method is provided, which is applied to configuring subband CQI feedback at a higher layer, wherein a serving cell of a terminal performs cooperative transmission with multiple cooperative cells, and the method includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the method comprises the steps of obtaining a CQI index differential offset level on each sub band of a serving cell and each sub band CQI index differential offset level of each cooperative cell in a plurality of cooperative cells, wherein the sub band CQI index differential offset level of the serving cell is obtained by subtracting the frequency band CQI index of the serving cell from the sub band CQI index of the serving cell, and the sub band CQI index differential offset level of the cooperative cells is obtained by subtracting the frequency band CQI index of the serving cell from the sub band CQI index of the cooperative cell. The overhead used by each sub-band CQI index differential offset level of each cooperative cell here is 2 bits.
Fig. 2 is a schematic diagram of a cooperative cell sub-band CQI index difference relationship in CoMP according to an embodiment of the present invention, as shown in fig. 2, taking 2 cooperative cells as an example, a sub-band CQI index of each cooperative cell is differentiated from a serving cell wireless CQI index, where the definition of the cooperative cell sub-band offset level is as follows:
b th CcellN thjSub band offset level (Bth C)cellN thjA sub band CQI index-Scell wideband CQI index
Wherein, <math>
<mrow>
<mn>1</mn>
<mo>≤</mo>
<msub>
<mi>n</mi>
<mi>j</mi>
</msub>
<mo>≤</mo>
<msub>
<mi>N</mi>
<msub>
<mi>C</mi>
<mrow>
<mi>cell</mi>
<mo>,</mo>
<mi>b</mi>
</mrow>
</msub>
</msub>
<mo>,</mo>
</mrow>
</math> the number of the b th cooperative cell. Subband differential off in CoMPThe specific relationship of set level is as follows: the CQI index on each sub of the cooperating cell is differentiated from the serving cell wideband CQI index,
at this time, the terminal feeds back the CQI index on each sub band of the serving cell and the differential offset level between the CQI index on each sub band of each cooperative cell and the serving cell wideband CQI index, and the overhead when feeding back the sub band configured at the higher layer is as follows:
in the above formula, B cells perform CoMP transmission, wherein,is a serving cellThe CQI feedback of each sub-band, <math>
<mrow>
<mn>2</mn>
<mo>*</mo>
<msub>
<mi>N</mi>
<msub>
<mi>C</mi>
<mrow>
<mi>cell</mi>
<mo>,</mo>
<mn>1</mn>
</mrow>
</msub>
</msub>
<mo>+</mo>
<mn>2</mn>
<mo>*</mo>
<msub>
<mi>N</mi>
<msub>
<mi>C</mi>
<mrow>
<mi>cell</mi>
<mo>,</mo>
<mn>2</mn>
</mrow>
</msub>
</msub>
<mo>+</mo>
<mo>·</mo>
<mo>·</mo>
<mo>·</mo>
<mo>·</mo>
<mo>·</mo>
<mo>·</mo>
<mo>+</mo>
<mn>2</mn>
<mo>*</mo>
<msub>
<mi>N</mi>
<msub>
<mi>C</mi>
<mrow>
<mi>cell</mi>
<mo>,</mo>
<mrow>
<mo>(</mo>
<mi>B</mi>
<mo>-</mo>
<mn>1</mn>
<mo>)</mo>
</mrow>
</mrow>
</msub>
</msub>
</mrow>
</math> is the differential CQI offset level of each sub band CQI index of each cooperative cell minus the serving cell wideband CQI index. The sub-band differential CQI offset level table may be an existing sub-band differential CQI offset level table, or may be redefined.
FIG. 3 is a schematic diagram of sub-band CQI feedback in CoMP according to an embodiment of the present invention, as shown in FIG. 3, serving cell sub-band CQI occupancyCooperative cell 1 sub band differential CQI occupancy (2 x N)cell，1bits), cooperative cell 2 sub band differential CQI occupancy (2 x N)cell，2A cooperative cell (B-1) sub band differential CQI occupancy (2 x N)cell，(B-1)bits)。
Further, the CQI information may further include: the method includes the steps of determining a wideband CQI index of a serving cell and a wideband CQI index differential offset level of each of a plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell. Here, the overhead used by the wideband CQI index differential offset level of each cooperative cell is 3 bits.
When the subband feedback of the high-layer configuration is performed, the feedback overhead of the LTE-a terminals wideband and subband is as follows:
according to the embodiment, the feedback overhead of the terminal is reduced when the sub-band CQI is fed back in the CoMP.
EXAMPLE III
According to an embodiment of the present invention, a CQI feedback method is provided, which is applied to a terminal to select subband CQI feedback, where a serving cell of the terminal performs cooperative transmission with multiple cooperative cells, and the method includes: the terminal feeds back CQI information to the network side, wherein the CQI information comprises: the method comprises the steps of obtaining a serving cell's wideband CQI index, a serving cell's wideband CQI index differential offset rank of each of a plurality of cooperating cells, a terminal-selected serving cell and an average CQI index differential offset rank of a plurality of better subbands in the plurality of cooperating cells, wherein the serving cell's wideband CQI index differential offset rank is the serving cell's wideband CQI index minus the serving cell's wideband CQI index, the average CQI index differential offset ranks of the plurality of better subbands are the serving cell's average CQI index minus the serving cell's wideband CQI index, and the overhead used by the serving cell's wideband CQI index differential offset rank of each of the cooperating cells is 3 bits.
Specifically, when the terminal selects the subband feedback, the terminal selects the serving cellCQI of a better sub-band, in each cooperating cellAnd in order to effectively reduce the feedback subband indication overhead of the terminal, the terminal can select subbands with similar CQI values from a plurality of superior subband sets for feedback, and in order to ensure that the feedback overhead is basically equivalent to that of the R8 terminal, the terminal is stipulated to select at most M superior subbands, and positions of the subbands are indicated by Lbit. The average CQI offset level over M subbands is defined as:
m superior sub-band average CQI offset levels selected by B coordinated serving cells (i.e., M superior sub-band average CQI index-S selected by B cells)cellwideband CQI index
At this time, the terminal feeds back the serving cell wideband CQI index (4bits) and each cooperative wideband CQI differential offset level (3bits), and reports M better sub band average CQI differential offset levels (2bits) comprehensively selected by multiple cooperative transmission cells. The feedback overhead is as follows:
4+3*(B-1)+L+2 bits
where L is the preferred M subband position indications.
According to the embodiment, when the terminal selects the sub-band feedback in the CoMP, the feedback overhead of the terminal is reduced.
The implementation process of the embodiment of the present invention will be described in detail below with reference to an example, which includes the following steps:
in the first step, the serving cell notifies each cell ID of the LTE-A terminal for cooperative transmission, and the terminal performs channel measurement. The LTE-A terminal measures the wireless band CQI and the sub band CQI from each cooperative cell to the terminal according to the common pilot frequency of each cooperative cell; the LTE-A terminal performs CQI feedback according to high-layer (namely RRC) configuration, if the RRC configuration terminal is wideband CQI feedback, the second step is performed, if the RRC configuration terminal is high-layer configured sub-band CQI feedback, the third step is performed, and if the RRC configuration terminal selects sub-band feedback, the fourth step is performed.
Secondly, when the RRC configures the terminal for wideband CQI feedback, the following operations are carried out:
the terminal feeds back the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each cooperative cell, and the wideband CQI index differential offset level of the cooperative cell is defined as:
b th Ccell wideband CQI offset level＝Scellwideband CQI index-b-th Ccell wideband CQI index
The wideband CQI differential offset level is obtained by subtracting the wideband CQI index of each cooperating cell from the wideband CQI index of the serving cell, and the feedback overhead is:
4(Scell wideband CQI)+3*(B-1)
thirdly, when the terminal configures the sub-band CQI feedback for the high layer, the following operations are carried out:
serving cell sub band differential offset level definition is the same as the prior art. The cooperative cell sub band differential offset level is defined as follows:
b th CcellN thjSub band offset level (Bth C)cellN thjA sub band CQI index-Scell wideband CQI index
The specific differences are as follows: the CQI index on each sub of the cooperating cell minus the serving cell wideband CQI index, <math>
<mrow>
<mn>1</mn>
<mo>≤</mo>
<msub>
<mi>n</mi>
<mi>j</mi>
</msub>
<mo>≤</mo>
<msub>
<mi>N</mi>
<msub>
<mi>C</mi>
<mrow>
<mi>cell</mi>
<mo>,</mo>
<mi>b</mi>
</mrow>
</msub>
</msub>
</mrow>
</math> is the nth of the b cooperative celljAnd (4) sub-bands. At this time, the terminal feeds back the CQI index offset level on each sub band of the serving cell and the differential offset level of each sub band CQI index and the serving cell wideband CQI index of each cooperative cell. The sub-band CQI feedback overhead is:
the feedback overhead of the LTE-A terminal wideband and sub-band CQI is as follows:
fourthly, when the RRC is configured to select the sub-band feedback, the following operations are carried out:
when the terminal selects the subband feedback, the service cell is selectedCQI of better sub-band, each cooperation cell is selected respectivelyAnd in order to effectively reduce the feedback subband indication overhead of the terminal, the terminal can select subbands with similar CQI values from a plurality of superior subband sets for feedback, and in order to ensure that the feedback overhead is basically equivalent to that of the R8 terminal, the terminal is stipulated to select at most M superior subbands, and the positions of the subbands are indicated by L bits. The average CQI offset level over M subbands is defined as:
m superior sub-band average CQI offset levels selected by B coordinated serving cells (i.e., M superior sub-band average CQI index-S selected by B cells)cellwideband CQI index
At this time, the terminal feeds back the serving cell wideband CQI index (4bits) and each cooperative wideband CQI differential offset level (3bits), and reports M better sub band average CQI differential offset levels (2bits) comprehensively selected by multiple cooperative transmission cells. The feedback overhead is as follows:
4+3*(B-1)+L+2 bits
where L is the preferred M subband position indications.
And fifthly, the LTE-A terminal can flexibly select three feedback modes of the second step, the third step and the fourth step for feedback according to the configuration of RRC.
In CoMP, the LTE-a terminal feeds back CQI information to a serving cell, or feeds back CQI information to multiple cells in cooperative transmission, where the CQI information includes a wideband CQI and a sub-CQI from the serving cell to the terminal, and a wideband CQI and a sub-CQI from each cooperating cell to the terminal, and the four kinds of CQI information are fed back in the above-mentioned second, third, and fourth steps.
The above implementation is described below with reference to specific examples.
Example one
Taking a high-level configuration terminal as subband feedback as an example, the feedback overhead of the LTE-a terminal is as follows:
when two cells perform CoMP transmission, and the number of subbands in each cell is equal, i.e. B is 2, suppose that When the temperature of the water is higher than the set temperature, by adopting the existing feedback method of the R8 terminal, the overhead is 4 × 2+2 × 14 ═ 36bits, and by adopting the method provided by the embodiment of the invention, the overhead is as follows: 4+ 2+ 7+3 is 35bits, so the feedback overhead is reduced by 1 bit.
Example two
When three cells are used for cooperative transmission, the system bandwidth is unchanged, B is 3, the feedback overhead of the existing feedback method is 4 × 3+2 × 7 × 3 ═ 54bits, and the feedback method provided by the embodiment of the present invention has the overhead of 4+2 × 7+3 × 2 ═ 52bits, so that the feedback overhead is reduced by 2 bits.
By the embodiment, the feedback overhead of the terminal is reduced, and the flexibility of CoMP scheduling is improved.
Device embodiment
According to an embodiment of the present invention, a terminal is provided. Fig. 4 is a block diagram of a terminal according to an embodiment of the present invention, and as shown in fig. 4, the terminal includes: a receiving module 42, a determining module 44, a feedback module 46, and a calling module 48, which are described in detail below.
A receiving module 42, configured to receive downlink control information from a network side, where the downlink control information is used to indicate a feedback mode of CQI feedback of a terminal; a determining module 44, connected to the receiving module 42, configured to determine, according to the downlink control information received by the receiving module 42, a feedback manner for the terminal to perform CQI feedback, where the feedback manner includes: broadband CQI feedback, high-level configuration sub-band CQI feedback and terminal selection sub-band CQI feedback; a feedback module 46, configured to feed back CQI information to the network side according to the feedback manner determined by the determining module, where the CQI information includes: a wideband CQI index and/or a sub-band CQI index, a wideband CQI index differential offset level and/or a sub-band CQI index differential offset level; and the calling module 48 is connected to the determining module 44 and the feedback module 46, and is used for calling the feedback module 46 to perform feedback according to the feedback mode determined by the determining module 44.
Specifically, the above-described feedback manner includes three cases, which will be described in detail below.
(1) If the feedback mode is wideband CQI feedback, the CQI information comprises: the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each of the plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
(2) If the feedback mode is sub-band CQI feedback configured for the high layer, the CQI information comprises: a CQI index offset level on each subband of a serving cell and a per subband CQI index differential offset level for each of a plurality of cooperating cells, wherein the subband CQI index differential offset level for a cooperating cell is the subband CQI index of the cooperating cell minus the wideband CQI index of the serving cell.
Further, the CQI information may further include: the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each of the plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
(3) If the feedback mode is sub-band CQI feedback selected by the terminal, the CQI information comprises: the terminal selects a serving cell from a plurality of cooperating cells, and selects a broadband CQI index differential offset level of each cooperating cell in the plurality of cooperating cells, wherein the broadband CQI index differential offset level of the cooperating cell is the broadband CQI index of the serving cell minus the broadband CQI index of the cooperating cell, and the average CQI index differential offset level of the plurality of preferred sub-bands is the average CQI index of the plurality of preferred sub-bands minus the broadband CQI index of the serving cell.
According to the embodiment, the terminal is provided, wherein the CQI information fed back to the network side comprises the broadband CQI index and/or the sub-band CQI index, the broadband CQI index differential offset level and/or the sub-band CQI index differential offset level, and the feedback overhead of the terminal can be reduced.
In summary, the above embodiments of the present invention can effectively reduce the feedback overhead of the terminal CQI during the coordinated multi-point transmission; differential feedback is carried out on the wideband CQI, so that the cost of wideband CQI feedback can be reduced, and the reduction of the feedback cost is more obvious along with the increase of the number of the cooperative cells; when subband feedback is selected for a terminal, better resources can be allocated to users when feedback overhead is appropriate. The network side can realize flexible resource scheduling according to the multi-cell channel information fed back by the terminal, that is, the CQI information fed back to the serving cell by the terminal includes the wideband CQI index of each cooperative cell and the channel information on each sub and the optimal sub, and the network side can synthesize the channel information to perform flexible resource allocation.
It will be apparent to those skilled in the art that the modules or steps of the present invention described above may be implemented by a general purpose computing device, they may be centralized on a single computing device or distributed across a network of multiple computing devices, and they may alternatively be implemented by program code executable by a computing device, such that they may be stored in a storage device and executed by a computing device, or fabricated separately as individual integrated circuit modules, or fabricated as a single integrated circuit module from multiple modules or steps. Thus, the present invention is not limited to any specific combination of hardware and software.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (13)
1. A Channel Quality Information (CQI) feedback method is applied to a terminal for broadband CQI feedback, wherein a serving cell of the terminal performs cooperative transmission with a plurality of cooperative cells, and the method comprises the following steps:
the terminal feeds back CQI information to a network side, wherein the CQI information comprises: the wideband CQI index of the serving cell and the wideband CQI index differential offset levels of each of the plurality of cooperating cells,
the wideband CQI index differential offset level of the cooperative cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperative cell.
2. The method of claim 1, wherein the overhead used for the wideband CQI index differential offset level for each cooperating cell is 3 bits.
3. A Channel Quality Information (CQI) feedback method is applied to high-level configuration sub-band CQI feedback, wherein a serving cell of a terminal and a plurality of cooperative cells carry out cooperative transmission, and the method is characterized by comprising the following steps:
the terminal feeds back CQI information to a network side, wherein the CQI information comprises: a CQI index differential offset level on each subband of the serving cell and each subband CQI index differential offset level of each of the plurality of cooperating cells,
the subband CQI index differential offset level of the serving cell is obtained by subtracting the broadband CQI index of the serving cell from each subband CQI index of the serving cell, and the subband CQI index differential offset level of the cooperative cell is obtained by subtracting the broadband CQI index of the serving cell from the subband CQI index of the cooperative cell.
4. The method of claim 3, wherein the overhead used for each subband CQI index differential offset level for each cooperating cell is 2 bits.
5. The method of claim 3, wherein the CQI information further comprises:
the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each of the plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
6. The method of claim 5, wherein the overhead used for the wideband CQI index differential offset level for each cooperating cell is 3 bits.
7. A Channel Quality Information (CQI) feedback method is applied to a terminal to select sub-band CQI feedback, wherein a serving cell of the terminal performs cooperative transmission with a plurality of cooperative cells, and the method comprises the following steps:
the terminal feeds back CQI information to a network side, wherein the CQI information comprises: a wideband CQI index of the serving cell, a wideband CQI index differential offset level for each of the plurality of cooperating cells, an average CQI index differential offset level for a plurality of subbands in the serving cell and the plurality of cooperating cells selected by the terminal,
the differential offset level of the wideband CQI index of the cooperative cell is obtained by subtracting the wideband CQI index of the cooperative cell from the wideband CQI index of the serving cell, and the differential offset level of the average CQI index of the multiple sub-bands is obtained by subtracting the wideband CQI index of the serving cell from the average CQI index of the multiple sub-bands.
8. The method of claim 7, wherein the overhead used for the wideband CQI index differential offset level for each cooperating cell is 3 bits.
9. A terminal, comprising:
a receiving module, configured to receive downlink control information from a network side, where the downlink control information is used to instruct a terminal to perform a feedback mode of aperiodic CQI feedback;
a determining module, configured to determine, according to the downlink control information received by the receiving module, a feedback manner for performing CQI feedback by the terminal;
a feedback module, configured to feed back CQI information to the network side according to the feedback manner determined by the determining module, where the CQI information includes: a wideband CQI index and/or a sub-band CQI index, a wideband CQI index differential offset level and/or a sub-band CQI index differential offset level;
and the calling module is used for calling the feedback module to feed back according to the feedback mode determined by the determining module.
10. The terminal of claim 9, wherein the feedback mode is wideband CQI feedback; the CQI information includes: the method includes the steps of obtaining a wideband CQI index of a serving cell and a wideband CQI index differential offset level of each of a plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
11. The terminal of claim 9, wherein the feedback manner is sub-band CQI feedback configured for a high layer; the CQI information includes: a CQI index offset level on each subband of a serving cell and a per subband CQI index differential offset level for each of a plurality of cooperating cells, wherein the subband CQI index differential offset level for a cooperating cell is the subband CQI index for the cooperating cell minus the wideband CQI index for the serving cell.
12. The terminal of claim 11, wherein the CQI information further comprises: the wideband CQI index of the serving cell and the wideband CQI index differential offset level of each of the plurality of cooperating cells, wherein the wideband CQI index differential offset level of a cooperating cell is the wideband CQI index of the serving cell minus the wideband CQI index of the cooperating cell.
13. The terminal of claim 9, wherein the feedback manner is a terminal selection sub-band CQI feedback; the CQI information includes: the terminal comprises a broadband CQI index of a serving cell, a broadband CQI index differential offset level of each cooperative cell in a plurality of cooperative cells, and an average CQI index differential offset level of a plurality of sub-bands in the serving cell and the plurality of cooperative cells selected by the terminal, wherein the broadband CQI index differential offset level of the cooperative cell is obtained by subtracting the broadband CQI index of the cooperative cell from the broadband CQI index of the serving cell, and the average CQI index differential offset level of the plurality of sub-bands is obtained by subtracting the broadband CQI index of the serving cell from the average CQI index of the plurality of sub-bands.
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| CN101969363B (en) * | 2010-09-30 | 2016-03-30 | 中兴通讯股份有限公司 | Channel state information feedback method and terminal |
| CN103262601B (en) * | 2010-12-13 | 2016-09-14 | 诺基亚通信公司 | For providing the mechanism of channel feedback in multi-cell communication |
| CN102594528B (en) * | 2011-01-10 | 2017-07-07 | 夏普株式会社 | The triggering method and equipment of non-periodic channel state information feedback |
| CN102611487B (en) * | 2011-01-24 | 2017-07-28 | 中兴通讯股份有限公司 | Feedback compression method and device under a kind of coordinated multipoint transmission |
| CN102625358B (en) * | 2011-02-01 | 2016-07-06 | 中兴通讯股份有限公司 | The method of feedback measurement, subscriber equipment and base station system |
| CN102780544A (en) * | 2011-05-12 | 2012-11-14 | 中兴通讯股份有限公司 | Channel information feedback method and device |
| CN103036655B (en) * | 2011-09-30 | 2018-06-19 | 中兴通讯股份有限公司 | A kind of method and apparatus for realizing CSI feedback |
| CN103580779B (en) * | 2012-07-20 | 2017-02-01 | 电信科学技术研究院 | Channel quality instruction information reporting and determining method and equipment |
| CN103780358B (en) * | 2012-10-24 | 2018-08-21 | 中兴通讯股份有限公司 | A kind of method and terminal of determining channel state information |
| WO2014179999A1 (en) * | 2013-05-10 | 2014-11-13 | 华为技术有限公司 | Method for reporting channel quality information (cqi), and user equipment |
| CN104348586A (en) * | 2013-08-09 | 2015-02-11 | 华为技术有限公司 | Terminal selection method, network equipment, terminal and system |
| CN106559168B (en) * | 2015-09-25 | 2019-11-05 | 华为技术有限公司 | Channel quality indicator CQI determines system and method in cooperative multi-point communication |
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