CN115102593B

CN115102593B - Method and device for selecting rank indication, baseband chip and terminal equipment

Info

Publication number: CN115102593B
Application number: CN202210663301.7A
Authority: CN
Inventors: 熊芳
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2022-06-13
Filing date: 2022-06-13
Publication date: 2024-02-02
Anticipated expiration: 2042-06-13
Also published as: CN115102593A

Abstract

A method, a device, a baseband chip and a terminal device for selecting rank indication are provided. The method comprises the following steps: determining mutual information corresponding to each of a plurality of rank indications; screening the multiple rank indications according to the mutual information corresponding to the multiple rank indications so as to obtain candidate sets of the rank indications; and selecting the rank indication to be reported from the candidate set according to the rank indication in the candidate set and the precoding matrix indication corresponding to the rank indication in the candidate set. According to the method and the device, the candidate set is screened out from the multiple rank indications according to the mutual information corresponding to the multiple rank indications, and then the rank indications in the screened set and the precoding matrix indications corresponding to the rank indications are traversed to select the rank indication to be reported, so that the calculation complexity can be reduced on the premise of guaranteeing the rank indication selection precision.

Description

Method and device for selecting rank indication, baseband chip and terminal equipment

Technical Field

The present disclosure relates to the field of communications technologies, and in particular, to a method, an apparatus, a baseband chip, and a terminal device for selecting rank indication.

Background

In the field of communication, MIMO technology is used to increase channel capacity. The MIMO technology performs precoding on one or more layers of data to be transmitted, and then transmits the precoded data through multiple antennas. In different channel environments, in order to increase the channel capacity on the premise of ensuring the communication quality, the number of layers of communication data is generally dynamically adjusted. Taking LTE communication as an example, the number of layers of data is typically determined by Rank Indicator (RI). However, the current method for selecting rank indication has high computational complexity, and cannot meet the communication requirement.

Disclosure of Invention

The application provides a method and device for selecting rank indication, a baseband chip and terminal equipment. Various aspects of embodiments of the present application are described below.

In a first aspect, a method of selecting a rank indication is provided, comprising: determining mutual information corresponding to each of a plurality of rank indications; screening the multiple rank indications according to the mutual information corresponding to the multiple rank indications so as to obtain candidate sets of the rank indications; and selecting the rank indication to be reported from the candidate set according to the rank indication in the candidate set and the precoding matrix indication corresponding to the rank indication in the candidate set.

In a second aspect, an apparatus for selecting a rank indication is provided, comprising: the determining module is used for determining mutual information corresponding to each of the plurality of rank indications; the screening module is used for screening the multiple rank indications according to the mutual information corresponding to the multiple rank indications so as to obtain candidate sets of the rank indications; and the selection module is used for selecting the rank indication to be reported from the candidate set according to the rank indication in the candidate set and the precoding matrix indication corresponding to the rank indication in the candidate set.

In a third aspect, there is provided a baseband chip comprising a processor for calling a program from a memory, causing a device on which the chip is mounted to perform the method of the first aspect.

In a fourth aspect, there is provided a chip comprising a processor for calling a program from a memory, causing a device on which the chip is mounted to perform the method of the first aspect.

In a fifth aspect, there is provided a terminal device comprising a memory for storing a program and a processor for invoking the program in the memory to perform the method according to the first aspect.

In a sixth aspect, a computer readable storage medium is provided, having stored thereon executable code, which when executed is capable of implementing the method of the first aspect.

According to the method and the device, the candidate set is screened out from the multiple rank indications according to the mutual information corresponding to the multiple rank indications, and then the rank indications in the screened set and the precoding matrix indications corresponding to the rank indications are traversed to select the rank indication to be reported, so that the calculation complexity can be reduced on the premise of guaranteeing the rank indication selection precision.

Drawings

Fig. 1 is a wireless communication system to which embodiments of the present application apply.

Fig. 2 is a flowchart of a method for selecting rank indication according to an embodiment of the present application.

Fig. 3 is a flow chart of a possible implementation method of step S210 in fig. 2.

Fig. 4 is a flowchart of another method for selecting rank indication according to an embodiment of the present application.

Fig. 5 is a flow chart illustrating another method for selecting rank indication according to an embodiment of the present application

Fig. 6 is a schematic structural diagram of an apparatus for selecting rank indication according to an embodiment of the present application.

Fig. 7 is a schematic structural diagram of a feedback device according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully, and it is apparent that the embodiments described are only some, but not all, of the embodiments of the present application.

Fig. 1 is a wireless communication system 100 to which embodiments of the present application apply. The wireless communication system 100 may include a network device 110 and a terminal device 120. Network device 110 may be a device that communicates with terminal device 120. Network device 110 may provide communication coverage for a particular geographic area and may communicate with terminal devices 120 located within the coverage area.

Fig. 1 illustrates one network device and two terminals, alternatively, the wireless communication system 100 may include multiple network devices, and each network device may include other numbers of terminal devices within a coverage area, which is not limited in this embodiment of the present application.

Optionally, the wireless communication system 100 may further include a network controller, a mobility management entity, and other network entities, which are not limited in this embodiment of the present application.

It should be understood that the technical solution of the embodiments of the present application may be applied to various communication systems, for example: fifth generation (5th generation,5G) systems or New Radio (NR), long term evolution (long term evolution, LTE) systems, LTE frequency division duplex (frequency division duplex, FDD) systems, LTE time division duplex (time division duplex, TDD), and the like. The technical scheme provided by the application can also be applied to future communication systems, such as a sixth generation mobile communication system, a satellite communication system and the like.

The Terminal device in the embodiments of the present application may also be referred to as a User Equipment (UE), an access Terminal, a subscriber unit, a subscriber station, a Mobile Station (MS), a Mobile Terminal (MT), a remote station, a remote Terminal, a mobile device, a user Terminal, a wireless communication device, a user agent, or a user equipment. The terminal device in the embodiment of the application can be a device for providing voice and/or data connectivity for a user, and can be used for connecting people, things and machines, such as a handheld device with a wireless connection function, a vehicle-mounted device and the like. The terminal device in the embodiments of the present application may be a mobile phone (mobile phone), a tablet (Pad), a notebook, a palm, a mobile internet device (mobile internet device, MID), a wearable device, a Virtual Reality (VR) device, an augmented reality (augmented reality, AR) device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in teleoperation (remote medical surgery), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation security (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), or the like.

It should be understood that all or part of the functionality of the communication device in this application may also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (e.g. a cloud platform).

In the communication field, channel state information can be introduced during data transmission to fully utilize channel conditions to improve communication efficiency. Taking the communication system as shown in fig. 1 as an example, the network device 110 may send a Reference Signal (RS) for performing channel measurement, for example, a Cell-specific Reference Signal (CRS), a demodulation Reference Signal (Demodulation Reference Signal, DMRS), a channel state information Reference Signal (Channel State Information Reference Signal, CSI-RS), and the like, to the terminal device 120.

After receiving the reference signal sent by the network device 110, the terminal device 120 may process the reference signal to obtain information related to communication. For example, terminal device 120 may process the CSI-RS to obtain channel information between network device 110 and terminal device 120.

Terminal device 120 may feed back channel information to network device 110 for network device 110 to modify the communication configuration based on the current channel information to thereby improve communication performance (e.g., to achieve relatively better communication quality or relatively higher communication rate). For example, terminal device 120 may feed back channel state information (Channel State Information, CSI) to network device 110 based on the CSI-RS, and network device 110 may select appropriate communication parameters to communicate with terminal device 120 based on the CSI. Terminal device 120 may report CSI over a wideband or a subband. Each sub-band may comprise a plurality of consecutive sub-carriers. The wideband may comprise a plurality of contiguous or non-contiguous subbands.

For systems incorporating large-scale MIMO (massive MIMO), network device 110 may transmit on different CSI-RS resources using different beams. To identify different CSI-RS resources, CSI-RS resource indications (CSI-RS Resource Indicator, CRI) are added. Terminal device 120 can select an optimal resource from a plurality of different CSI-RS resources and report CRI to network device 110. Based on the selected CSI-RS resources, terminal device 120 may calculate CSI for feedback channel information. The specific content of CSI reporting may be selected according to the actual channel configuration. For example, CSI may include channel quality indication (Channel Quality Indicator, CQI), precoding matrix indication (Precoding Matrix Indicator, PMI), rank Indicator (RI), and so on.

RI may be used to indicate the number of layers of valid data. The number of layers of valid data affects the channel capacity. It will be appreciated that the larger the number of valid data layers that can be transmitted, the greater the channel capacity. But the more the number of active data layers, the greater the interference between the data. Thus, the accuracy of selecting RI has a great influence on the efficiency and quality of communication. For example, the RI supportable by the current channel is 2, and if the RI is selected to be 1, the communication performance will be seriously lost (e.g., the communication rate provided is low, and the communication rate actually supportable). If RI is 3, the channel communication quality may not meet the requirement (e.g., the block error rate is higher than the block error rate threshold of the communication).

In order to ensure the accuracy of selecting RI, the related art proposes a method for jointly estimating RI and PMI. The method selects the rank indication to be reported by combining RI and PMI selection, by evaluating the maximum mutual information (Mutual Information, MI) in the combination. The mutual information can reflect the statistical constraint degree between the input random variable and the output random variable, and can also represent the transmissible information quantity of the current channel. The method is described in detail below.

An optional set of RI is first obtained from radio resource control (Radio Resource Control, RRC) signaling, which may be denoted as 1R. Where R represents RI, and R represents the maximum RI that the wireless communication system can support. For NR systems, RRC signaling can directly configure an alternative set of RIs. The terminal device may read the selectable set of RIs directly from the RRC signaling. The selectable set includes a plurality of RIs. As one example, when the maximum RI that the wireless communication system can support is 4, the selectable set of RIs may be {1,2,3,4}.

Then, for each RI in the selectable set of RIs, a PMI set corresponding to the current RI is determined, and the MI of the current RI is determined based on the PMI set corresponding to the current RI. For example, RI 2 is selected from the above-described alternative sets {1,2,3,4} of RI, and then the PMI set when RI is 2 is determined. In some embodiments, the PMI set may be represented in the form of a codebook. And finally, calculating the MI corresponding to each PMI in the PMI set when the RI is 2, and comparing the MI corresponding to each PMI. Wherein the maximum MI can be determined as the MI at the current RI. Wherein MI under each PMI can be expressed as MI _rk R represents the RI value (e.g., 2), and k represents the PMI index value (e.g., PMI value). The MI at the RI (i.e., the maximum MI) can be expressed as MI _r 。

And traversing all the RI in the RI selectable set to determine the MI of each RI in all the RI, and comparing the MI corresponding to different RI to obtain the largest MI. And the RI and PMI corresponding to the maximum MI are the optimal RI and PMI, and the RI corresponding to the maximum MI is the RI to be reported selected from the selectable set of RI. Wherein, the optimal RI and PMI can be expressed as:

{r _bset ，PMI _best }＝argmax(MI _r )0≤r＜R

as an example, repeating the steps described above for RI of 2 for 1, 3 and 4 in the optional set {1,2,3,4} of RI results in MI for RI of 1,2,3 and 4, respectively ₁ 、MI ₂ 、MI ₃ 、MI ₄ . The MI is ₁ 、MI ₂ 、MI ₃ 、MI ₄ The RI corresponding to the largest value in the report is the RI to be reported.

The method for selecting the RI to be reported by jointly estimating the RI and the PMI has better performance, but the method needs to traverse each RI in the selectable set of the RI obtained according to the RRC signaling and traverse the PMI set corresponding to each RI so as to calculate the MI for each PMI in the PMI set. This results in a very large computational effort and a high requirement for the computational power of the terminal device, which is very complex to implement. Especially for NR or littm 9 modes, the computational complexity involved in selecting the rank indication to be reported using the above method is much higher, which is difficult to achieve, since the number of PMI sets may reach hundreds or even thousands.

In view of this, the present application provides a method for selecting rank indication, which can reduce the computational complexity of selecting rank indication while ensuring the accuracy of selecting rank indication.

Fig. 2 is a flowchart of a method for selecting rank indication according to an embodiment of the present application. As shown in fig. 2, the method for selecting rank indication provided in the present application includes steps S210 to S230.

In step S210, MI corresponding to each of the plurality of RIs is determined.

The plurality of RIs in the embodiments of the present application may be RIs in the selectable set of RIs obtained according to RRC signaling as described above. The MI corresponding to each RI is the MI corresponding to each RI in the RI selectable set. It is understood that in alternative sets of RIs, the MI corresponding to each RI may be completely or partially different, e.g., may appear as a different magnitude of MI values.

Determining the MI corresponding to each of the plurality of RIs in the embodiments of the present application may be understood as calculating the MI corresponding to each of the plurality of RIs by a method independent of PMI selection, that is, the calculation of the MI corresponding to each of the plurality of RIs is independent of PMI. For example, the MI corresponding to each of the plurality of RIs is a wideband MI corresponding to each of the plurality of RIs.

In step S220, the multiple RIs are filtered according to the MI corresponding to each of the multiple RIs, so as to obtain candidate sets of RIs.

The candidate set of RIs in the embodiments of the present application may be understood as a set formed by a part of RIs screened out from the above-mentioned multiple RIs. The size of the screening set may be configured as desired.

The embodiment of the present application does not specifically limit the form of screening the plurality of RIs according to the MI corresponding to each of the plurality of RIs. For example, the filtering may be performed by the size of the MI value corresponding to each RI of the plurality of RIs. Specifically, the MI values corresponding to each RI in the plurality of RIs are arranged in the order from large to small, and then the RIs corresponding to the MI in the previous orders are screened out to form the candidate set of RIs. For this way, the size of the screening set may be configured by setting a specific order of the screening.

Alternatively, the distance between the combined RI and the size of the MI value corresponding to each RI in the plurality of RIs may be selected. Specifically, the MI values corresponding to each RI in the plurality of RIs are arranged in order from large to small, the candidate set of adding RI corresponding to the largest MI value to RI is screened out, and then the candidate set of adding RI with a plurality of RI close to the RI in the candidate set of adding RI is screened out from the rest of the plurality of RIs. In this way, the size of the screening set can be configured by setting the distance between the remaining portion of the RIs of the screen and the RI corresponding to the largest MI value.

In step S230, according to the RI in the candidate set and the PMI corresponding to the RI in the candidate set, the RI to be reported is selected from the candidate set.

The RI to be reported may be information that CSI needs to be reported. When the CSI also needs to report other information, the RI to be reported can participate in the calculation of other information to be reported. For example, the RI to be reported may be used to calculate PMI, CQI, PTI and other parameters.

In the embodiment of the present application, selecting the RI to be reported from the candidate set according to the RI in the candidate set and the PMI corresponding to the RI in the candidate set may be understood as selecting the RI to be reported from the candidate set by combining the RI and PMI selection and evaluating the maximum MI in the combination.

Specifically, for each RI in the candidate set, a PMI set corresponding to the current RI is determined, and the MI of the current RI is determined based on the PMI set corresponding to the current RI. And traversing all the RI in the candidate set to determine the MI of each RI in all the RI, and comparing the MI corresponding to different RI to obtain the largest MI. The RI and PMI corresponding to the maximum MI are the optimal RI and PMI, and the RI corresponding to the maximum MI is the RI to be reported selected from the candidate set

Through implementation of the embodiment of the application, the mutual information can be used for screening a plurality of RI to form a candidate set, and then the RI in the candidate set and the corresponding PMI are utilized for joint estimation to select the RI to be reported. Therefore, the accuracy of RI in screening can be ensured, and the calculated amount in RI joint estimation can be reduced, so that the method reduces the calculation complexity on the premise of ensuring the accuracy of the selected RI to be reported.

As described above, the MI corresponding to each of the plurality of RIs may be a broadband MI corresponding to each of the plurality of RIs. In the embodiment of the present application, the determination method of the wideband MI corresponding to each of the plurality of RIs is not specifically limited. For example, the wideband eigenvalues may be calculated directly by the wideband cross-correlation matrix, and then the wideband MI corresponding to each of the plurality of RIs is determined based on the wideband eigenvalues.

Alternatively, as shown in fig. 3, the step S210 may specifically include the step S211 and the step S212.

In step S211: the sub-bands MI corresponding to each of the plurality of RI's are determined.

In step S212: and determining the broadband MI corresponding to each of the plurality of RI according to the sub-bands MI corresponding to each of the plurality of RI.

The subbands and the wideband may be the resources for reporting CSI described above, and the wideband may include a plurality of subbands. In the embodiment of the present application, determining the wideband MI corresponding to each of the plurality of RIs according to the subband MI corresponding to each of the plurality of RIs may be to accumulate the subband MI corresponding to each of the plurality of RIs to obtain the corresponding wideband mutual information.

As an example, a specific calculation method may refer to the following formula:

where J represents the number of subbands and J represents the total number of subbands that the wideband contains.

The implementation method is that the sub-band MI corresponding to each of the plurality of RI is determined firstly and then the broadband MI corresponding to each of the plurality of RI is determined based on the sub-band MI, so that the broadband MI can be guaranteed to comprise both the sub-band characteristic and the broadband characteristic, the characteristic of a channel is reflected better, the robustness of the calculation method of the MI corresponding to each of the plurality of RI is higher, and the finally selected RI to be reported is higher in precision. It should be appreciated that the higher the selection accuracy of the RI to be reported, the better the communication performance of the wireless communication system. Therefore, the method provided by the embodiment of the application can ensure the communication performance and meet the communication requirement.

In the embodiment of the present application, a specific implementation manner of determining the sub-bands MI corresponding to each of the multiple RIs may be: and determining a subband characteristic value according to the subband channel cross-correlation matrix, and then determining the subbands MI corresponding to each of the plurality of RI according to the subband characteristic value.

The subband channel cross correlation matrix may be understood as a channel estimation matrix, which may be a subband channel covariance matrix calculated by whitening the channel estimate.

The subband eigenvalues may be eigenvalues obtained by decomposing the subband cross-correlation matrix. There may be many ways to determine the sub-bands MI corresponding to each of the RIs according to the sub-band feature values. As an implementation manner, the signal-to-noise ratio (Signal to Interference plus Noise Ratio, SINR) corresponding to each of the plurality of RIs may be determined according to the subband eigenvalue, and then the subband MI corresponding to each of the plurality of RIs may be determined according to the SINR corresponding to each of the plurality of RIs. The specific implementation manner of determining the sub-band MI corresponding to each of the plurality of RIs according to the SINR corresponding to each of the plurality of RIs may be to substitute the SINR corresponding to each of the plurality of RIs into the mapping function to calculate the sub-band MI corresponding to each of the plurality of RIs.

It can be understood that the energy corresponding to each eigenvalue is different in the sub-band channel cross-correlation matrix corresponding to different data layers. For example, the energy corresponding to the eigenvalue when the number of data layers is 1 (RI is 1) is generally larger than the energy corresponding to the eigenvalue for each layer of data when the number of data layers is 2 (RI is 2). In view of this, before determining the signal-to-noise ratios corresponding to the RI's respectively using the eigenvalues, the subband eigenvalues may be normalized, and then the subband MI may be determined according to the normalized subband eigenvalues using the mapping function. By the method, the calculation accuracy of MI can be effectively improved.

In a MIMO system, the more the number of effective data layers, the greater the interference between the data. If the condition of the channel is judged erroneously in the calculation process, the wideband MI corresponding to each RI may not be different, and the RI may be selected to cause jitter. That is, if the data interference considered is small in the actual calculation, jitter is a problem.

For ease of understanding, the dithering will be briefly described below. Assuming that the current RI is 2, a new RI is calculated to be 3. However, the wideband mutual information obtained when RI is 3 is not much different from that obtained when RI is 2. At this time, if RI is switched to 3, the communication quality may be poor (for example, the block error rate is high), and a jitter phenomenon in the communication process occurs.

In order to fully consider the interference, the problem that the effective data layer is not matched with the interference in the calculation process due to the fact that the calculation of the broadband MI corresponding to each RI is different from the actual PMI is avoided, and therefore the finally selected RI can shake.

In some embodiments, as shown in fig. 4, the method may further include step S410 before step S220.

In step S410, MI corresponding to each of the plurality of RIs is compensated according to the penalty factor.

The penalty factor can be understood as a compensation factor that approximates the calculated MI to the MI of the real channel, wherein the larger the RI value, the larger the penalty formed by the penalty factor. The penalty factor may be obtained in a number of ways. For example, penalty factors may be obtained by simulation. In order to improve the accuracy of the penalty factors, multiple channel conditions can be simulated to obtain penalty factors under each channel condition.

The specific implementation manner of compensating the MI corresponding to each of the plurality of RIs according to the penalty factor may be performed according to the following formula:

wherein MI is broadband mutual information before compensation,for the compensated broadband mutual information, g is penalty factor, and r is RI corresponding to the current MI. The penalty factor g is less than 1.

By implementing the embodiment of the application, the penalty factors applicable to various channel conditions can be utilized to compensate the broadband mutual information, the compensation result does not need to depend on the accuracy of judging the channel conditions, the RI is switched only when the RI with higher RI can provide higher communication performance, the jitter phenomenon in communication is effectively avoided, the communication rate and the communication quality are considered, and the robustness of the RI selection result is effectively improved.

The method of RI selection provided in the embodiments of the present application is exemplarily described below in a specific embodiment in conjunction with fig. 5.

As shown in fig. 5, the method of selecting RI may specifically include steps S510 to S590. It should be appreciated that multiple reference signals (e.g., multiple CSI-RSs) may be included in the wireless communication process. Different reference signals may correspond to different beam resources. The scheme provided by the embodiment of the application is a method for selecting RI under a CSI-RS resource.

In step S510, whitening processing is performed on the subband channel estimates.

In step S520, a sub-band channel cross-correlation matrix is calculated, and in particular, the sub-band channel cross-correlation matrix may be calculated using the following formula.

Wherein R is _sb (j) Representing the j-th sub-band channel cross-correlation matrix. N (N) _j Representing the number of samples of the jth subband.Indicating the j-th sub-band channel estimation result. />Representing the conjugate transpose of the j-th sub-band channel estimation result.

In step S530, the eigenvalues of the subband j are calculated. Specifically, the eigenvalue of the subband j can be obtained by utilizing the eigenvalue decomposition, and the calculation formula is as follows:

λ(j)＝eig(R _sb (j))

in step S540, SINR corresponding to each RI is calculated. The specific calculation formula is as follows:

where r represents the value of the rank indication. l represents each layer of data of rank indication r. SINR (Signal to interference plus noise ratio) _r，l (j) Representing the signal-to-noise ratio of each layer of data corresponding to each rank indication r for each subband j.The normalization factor may be represented. By normalizing the signal to noise ratio corresponding to each layer of data, the calculation accuracy can be improved, and the comparison between channels with different data layers is facilitated.

In step S550, the subband MI corresponding to each RI in the selectable set of RIs is calculated and the total subband MI corresponding to each RI in the selectable set of RIs is calculated. The specific formula is as follows:

MI _r，l (j)＝f(SINR _r，l (j))

wherein MI is _r，l (j) Representing subband MI, f (x) represents the mapping function of the signal-to-noise ratio SINR to subband MI.

Wherein MI is _r (j) Indicating the total MI of the subbands.

In step S560, the MI of the wideband corresponding to each RI in the selectable set of RIs is calculated. The calculation formula is as follows:

wherein MI is _r Represents the MI for the wideband. j represents a subband. J represents the total number of subbands.

In step S570, penalty processing is performed on the MI of the broadband corresponding to each RI in the optional set, and RI is screened based on the processed MI. The treated MI can be expressed as follows:

wherein,MI for processed broadband mutual information _r (k) For the broadband mutual information before processing, g is penalty factor, and r is rank indication corresponding to the current mutual information.

The RI screening process based on the treated MI may specifically be: on the resourceOrdering and then selecting the maximum +.>The corresponding RI enters the RIAnd selecting the RI values which are lower than the MI and are near the RI into the candidate set. The candidate set size may be configured and the candidate set of the finally selected RI may be defined as +.>

With continued reference to fig. 5, in step S580, under the candidate set of RIs, the joint PMIs calculate MI corresponding to each RI. For a specific method, reference may be made to the foregoing description, and the MI corresponding to each RI in the candidate set may be expressed as:

in step S590, the RI to be reported is selected according to the MI corresponding to each RI. The RI to be reported may be an RI corresponding to the largest MI among the MI corresponding to each RI. The RI to be reported can be expressed as:

the scheme provided by the embodiment of the application can firstly calculate the eigenvalue by using the subband channel cross-correlation matrix, and estimate MI under different rank indications (or rank), so as to perform preliminary screening on the selectable set of RI, and keep an effective RI set (namely, the candidate set of RI). And traversing the RI in the candidate set of the RI, and calculating the MI by combining the PMI to select the RI to be reported from the candidate set. The method can ensure the accuracy of RI selection to ensure the performance of the communication system. Meanwhile, the complexity of the calculation algorithm can be reduced to a certain extent.

Method embodiments of the present application are described above in detail in connection with fig. 1-5, and apparatus embodiments of the present application are described below in detail in connection with fig. 6 and 7. It is to be understood that the description of the method embodiments corresponds to the description of the device embodiments, and that parts not described in detail can therefore be seen in the preceding method embodiments.

Fig. 6 is a schematic structural diagram of an apparatus for selecting rank indication according to an embodiment of the present application. As shown in fig. 6, an apparatus 600 for selecting a rank indication may include a determination module 610, a screening module 620, and a selection module 630.

The determining module 610 is configured to determine mutual information corresponding to each of the plurality of rank indications.

The filtering module 620 is configured to filter the multiple rank indications according to mutual information corresponding to the multiple rank indications, so as to obtain a candidate set of rank indications.

The selecting module 630 is configured to select, from the candidate set, a rank indication to be reported according to the rank indication in the candidate set and a precoding matrix indication corresponding to the rank indication in the candidate set.

Optionally, the mutual information corresponding to each of the plurality of rank indications is wideband mutual information corresponding to each of the plurality of rank indications, and the determining module 610 is specifically configured to: determining subband mutual information corresponding to each of the plurality of rank indications; and determining broadband mutual information corresponding to each of the plurality of rank indications according to the subband mutual information corresponding to each of the plurality of rank indications.

Optionally, the apparatus 600 further comprises a compensation module 640 for: and compensating the mutual information corresponding to each of the plurality of rank indications according to a penalty factor before screening the plurality of rank indications according to the mutual information corresponding to each of the plurality of rank indications.

Optionally, the compensation module 640 is specifically configured to: according toCompensating mutual information corresponding to each of the plurality of rank indications, wherein MI is wideband mutual information before compensation,>for the compensated wideband mutual information, g is penalty factor, and r is rank indication corresponding to the current mutual information.

Optionally, the determining module 610 is configured to: determining a subband characteristic value according to the subband channel cross-correlation matrix; and determining the sub-band mutual information corresponding to each of the plurality of rank indications according to the sub-band characteristic values.

Optionally, the determining module 610 is configured to: determining signal-to-noise ratios corresponding to the multiple rank indications according to the subband eigenvalues; and determining the subband mutual information corresponding to each of the plurality of rank indications according to the signal to noise ratio corresponding to each of the plurality of rank indications.

Fig. 7 is a schematic structural diagram of a feedback device of an embodiment of the present application. The dashed lines in fig. 7 indicate that the unit or module is optional. The apparatus 700 may be used to implement the methods described in the method embodiments above. The apparatus 700 may be a baseband chip, a terminal device, or a network device.

The apparatus 700 may include one or more processors 710. The processor 710 may support the apparatus 700 to implement the methods described in the method embodiments above. The processor 710 may be a general purpose processor or a special purpose processor. For example, the processor may be a central processing unit (central processing unit, CPU). Alternatively, the processor may be another general purpose processor, a digital signal processor (digital signal processor, DSP), an application specific integrated circuit (application specific integrated circuit, ASIC), an off-the-shelf programmable gate array (field programmable gate array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The apparatus 700 may also include one or more memories 720. The memory 720 has stored thereon a program that is executable by the processor 710 to cause the processor 710 to perform the method described in the method embodiments above. The memory 720 may be separate from the processor 710 or may be integrated into the processor 710.

The apparatus 700 may also include a transceiver 730. Processor 710 may communicate with other devices or chips through transceiver 730. For example, the processor 710 may transmit and receive data to and from other devices or chips through the transceiver 730.

The embodiment of the application also provides a baseband chip, which comprises a processor. The baseband chip may be used to invoke a program from a memory, so that a device in which the baseband chip is installed performs the method performed by the terminal device in the various embodiments of the present application.

The embodiment of the application also provides a computer readable storage medium for storing a program. The computer-readable storage medium may be applied to a terminal device or a network device provided in the embodiments of the present application, and the program causes a computer to execute the method performed by the terminal device in the embodiments of the present application.

Embodiments of the present application also provide a computer program product. The computer program product includes a program. The computer program product may be applied to a terminal device or a network device provided in embodiments of the present application, and the program causes a computer to execute the method executed by the terminal device in the embodiments of the present application.

The embodiment of the application also provides a computer program. The computer program can be applied to a terminal device or a network device provided in embodiments of the present application, and causes a computer to execute a method executed by the terminal device in each embodiment of the present application.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any other combination. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line (Digital Subscriber Line, DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., a floppy Disk, a hard Disk, a magnetic tape), an optical medium (e.g., a digital video disc (Digital Video Disc, DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), or the like.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of selecting a rank indication, comprising:

determining mutual information corresponding to each of a plurality of rank indications;

screening the multiple rank indications according to the mutual information corresponding to the multiple rank indications so as to obtain candidate sets of the rank indications;

and selecting the rank indication to be reported from the candidate set according to the rank indication in the candidate set and the precoding matrix indication corresponding to the rank indication in the candidate set.

2. The method of claim 1, wherein the mutual information corresponding to each of the plurality of rank indications is wideband mutual information corresponding to each of the plurality of rank indications,

the determining mutual information corresponding to each of the plurality of rank indications includes:

determining subband mutual information corresponding to each of the plurality of rank indications;

and determining broadband mutual information corresponding to each of the plurality of rank indications according to the subband mutual information corresponding to each of the plurality of rank indications.

3. The method of claim 2, wherein prior to screening the plurality of rank indications based on mutual information corresponding to each of the plurality of rank indications, the method further comprises:

and compensating mutual information corresponding to each of the plurality of rank indications according to a penalty factor.

4. The method of claim 3, wherein compensating for mutual information corresponding to each of the plurality of rank indications according to a penalty factor comprises:

according toCompensating mutual information corresponding to each of the plurality of rank indications, wherein MI is wideband mutual information before compensation,>for the compensated wideband mutual information, g is penalty factor, and r is rank indication corresponding to the current mutual information.

5. The method of claim 2, wherein the determining sub-band mutual information for each of the plurality of rank indications comprises:

determining a subband characteristic value according to the subband channel cross-correlation matrix;

and determining the sub-band mutual information corresponding to each of the plurality of rank indications according to the sub-band characteristic values.

6. The method of claim 5, wherein the determining the subband mutual information for each of the plurality of rank indications based on the subband eigenvalues comprises:

determining signal-to-noise ratios corresponding to the multiple rank indications according to the subband eigenvalues;

and determining the subband mutual information corresponding to each of the plurality of rank indications according to the signal to noise ratio corresponding to each of the plurality of rank indications.

7. An apparatus for selecting a rank indication, comprising:

the determining module is used for determining mutual information corresponding to each of the plurality of rank indications;

the screening module is used for screening the multiple rank indications according to the mutual information corresponding to the multiple rank indications so as to obtain candidate sets of the rank indications;

and the selection module is used for selecting the rank indication to be reported from the candidate set according to the rank indication in the candidate set and the precoding matrix indication corresponding to the rank indication in the candidate set.

8. The apparatus of claim 7, wherein the mutual information corresponding to each of the plurality of rank indications is wideband mutual information corresponding to each of the plurality of rank indications, and wherein the determining module is configured to:

9. The apparatus of claim 8, further comprising a compensation module to: and compensating the mutual information corresponding to each of the plurality of rank indications according to a penalty factor before screening the plurality of rank indications according to the mutual information corresponding to each of the plurality of rank indications.

10. The apparatus of claim 9, wherein the compensation module is configured to: according toCompensating mutual information corresponding to each of the plurality of rank indications, wherein MI is wideband mutual information before compensation,>for the compensated wideband mutual information, g is penalty factor, and r is rank indication corresponding to the current mutual information.

11. The apparatus of claim 8, wherein the determining module is configured to:

12. The apparatus of claim 11, wherein the determining module is configured to:

13. A baseband chip comprising a processor for invoking a program from memory to cause a device in which the baseband chip is installed to perform the method of any of claims 1-6.

14. A terminal device comprising a memory for storing a program and a processor for invoking the program in the memory to perform the method of any of claims 1-6.