WO2018059161A1 - 无线通信方法和无线通信装置 - Google Patents
无线通信方法和无线通信装置 Download PDFInfo
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- WO2018059161A1 WO2018059161A1 PCT/CN2017/098405 CN2017098405W WO2018059161A1 WO 2018059161 A1 WO2018059161 A1 WO 2018059161A1 CN 2017098405 W CN2017098405 W CN 2017098405W WO 2018059161 A1 WO2018059161 A1 WO 2018059161A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
- H04B7/0478—Special codebook structures directed to feedback optimisation
- H04B7/0479—Special codebook structures directed to feedback optimisation for multi-dimensional arrays, e.g. horizontal or vertical pre-distortion matrix index [PMI]
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0678—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission using different spreading codes between antennas
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
- H04B7/0695—Hybrid systems, i.e. switching and simultaneous transmission using beam selection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/08—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
- H04B7/0868—Hybrid systems, i.e. switching and combining
- H04B7/088—Hybrid systems, i.e. switching and combining using beam selection
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W24/00—Supervisory, monitoring or testing arrangements
- H04W24/08—Testing, supervising or monitoring using real traffic
Definitions
- the present invention relates to a wireless communication method and a wireless communication device, and more particularly to a wireless communication method and a wireless communication device for a large-scale multiple input multiple output communication system.
- MIMO Massive Multi-Input Multi-Output
- Millimeter Wave technology have been considered as part of the future 5G key technologies, which have attracted widespread attention in academia and industry.
- the millimeter-wave band has a large amount of available spectrum resources to meet the growing traffic demands of mobile communications.
- the antenna size of the millimeter wave system is also small, which makes it possible to place hundreds or even thousands of antennas in a small space, which is more advantageous for the large-scale antenna technology in the real system.
- the beamforming technology provided by large-scale antennas can effectively compensate for the shortcomings of millimeter-wave channel path fading, and it is possible to apply millimeter-wave technology to mobile communications.
- Full Dimension Multiple Output Multiple Output (Full Dimension MIMO, FD-MIMO) is also one of the hot spots in the industry.
- FD-MIMO can provide both horizontal and vertical degrees of freedom.
- FD-MIMO can deploy more antennas in a limited space, thereby improving the performance of spatial diversity and multiplexing.
- the inventors of the present invention have found that the overhead of the existing beamforming training mechanism is still large when the base station is equipped with a large-scale antenna, especially a multi-dimensional antenna array. Further, in the case that both the user equipment and the base station are configured with multiple antennas, as the number of antennas and the number of users increase, the overhead for beamforming training becomes larger and larger. Moreover, when there are multiple users, it is necessary to determine a corresponding beamforming parameter for each user to transmit, for which the problem of overhead for beamforming training is more prominent.
- the present application proposes an improved beamforming training technique, the basic idea of which is to pass
- the configuration parameters to be determined (for example, the configuration parameters of the phase shifter corresponding to the antenna, such as the weight vector) are decomposed into several sub-configuration parameters, and the sub-configuration parameters are respectively determined by the corresponding training, thereby being able to obtain the most Yuko configuration parameters are used for configuration.
- horizontal beam training and vertical beam training may be separately performed to obtain optimal horizontal direction sub-configuration parameters and optimal vertical direction sub-configuration parameters, respectively, and based on The optimal horizontal and vertical sub-configuration parameters are respectively obtained to configure the phase shifter corresponding to the antenna, for example, the phase shifter based on the Kronenko product of the sub-configuration parameters of the two directions.
- an electronic device for a first communication device of a wireless communication system wherein the first communication device is arranged with a plurality of antennas
- the electronic device comprising: processing circuitry configured to: Configuring a first transmission of the first communication device to the second communication device based on the plurality of sets of first sub-configuration parameters, respectively, such that a specific set of first sub-configuration parameters are determined based on the first transmission-related information, wherein the plurality of groups a first sub-configuration parameter is associated with a first direction relative to a plane of the plurality of antennas; a second transmission of the first communication device to the second communication device is respectively configured based on the plurality of sets of second sub-configuration parameters, such that a particular group a second sub-configuration parameter is determined based on the second transmission-related information, wherein the plurality of sets of second sub-configuration parameters are associated with a second direction relative to the plane, the second direction being positive with the first direction And configuring a subsequent transmission of the first
- an electronic device for a second communication device of a wireless communication system includes processing circuitry configured to: acquire, by the first communication device, a plurality of groups a first transmission-related information configured by a sub-configuration parameter, wherein the plurality of sets of first sub-configuration parameters are associated with a first direction relative to a plane of the plurality of antennas of the first communication device; and the obtaining is based on the first communication device a plurality of sets of second sub-configuration parameters respectively configured with second transmission-related information, the plurality of sets of second sub-configuration parameters being associated with a second direction relative to the plane, the second direction being orthogonal to the first direction
- a specific set of first sub-configuration parameters determined based on the first transmission-related information and a specific set of second sub-configuration parameters determined based on the second transmission-related information are determined for configuration A particular set of first configuration parameters of a subsequent transmission by the communication device to the second communication device.
- a method for a wireless communication system includes a first communication device and a second communication device, the first communication device being arranged with a plurality of antennas
- the method includes separately configuring a first transmission of the first communication device to the second communication device based on the plurality of sets of first sub-configuration parameters, such that the specific set of first sub-configuration parameters are determined based on the first transmission-related information
- the plurality of sets of first sub-configuration parameters are associated with a first direction relative to a plane of the plurality of antennas; respectively configured based on a plurality of sets of second sub-configuration parameters a second transmission by the first communication device to the second communication device such that a particular set of second sub-configuration parameters are determined based on the second transmission-related information, wherein the plurality of sets of second sub-configuration parameters are relative to the A second direction of the plane is associated, the second direction being orthogonal to the first direction; and configuring a subsequent transmission of the second communication device
- a method for a wireless communication system includes a first communication device and a second communication device, the first communication device being arranged with a plurality of antennas
- the method includes obtaining first transmission related information respectively configured by the first communication device based on the plurality of sets of first sub-configuration parameters, wherein the plurality of sets of first sub-configuration parameters and the first of the planes of the plurality of antennas relative to the first communication device Aligning directions; and acquiring second transmission related information respectively configured by the first communication device based on the plurality of sets of second sub-configuration parameters, the plurality of sets of second sub-configuration parameters being associated with a second direction relative to the plane
- the second direction is orthogonal to the first direction; wherein the specific set of first sub-configuration parameters determined based on the first transmission related information and the specific determined based on the second transmission related information
- a set of second sub-configuration parameters determines a particular set of first configuration parameters for configuring subsequent transmissions by the first communication device to the second
- the overhead for beamforming training in wireless communication can be reduced.
- the signaling overhead can be further reduced while keeping the beamforming training overhead low.
- FIG. 1 is a diagram showing the structure of a prior art base station.
- FIG. 2 is a diagram showing a user terminal configured with a single antenna.
- FIG. 3 is a diagram showing a user terminal configured with a plurality of antennas.
- 4a and 4b are diagrams showing configurations of a base station side and a UE side in a single-user system, respectively.
- 5a and 5b are diagrams showing configurations of a base station side and a UE side in an analog-digital hybrid precoding architecture, respectively.
- Figures 6a and 6b show schematic diagrams of a fully connected phase shifting network and a sub-connected phase shifting network, respectively.
- Figure 7a shows a schematic diagram of an electronic device for a communication device in a wireless communication system, in accordance with one embodiment of the present invention.
- Figure 7b shows a schematic diagram of an electronic device for another communication device in a wireless communication system, in accordance with one embodiment of the present invention.
- FIG. 8 is a flow chart showing beamforming training using the electronic device of FIG. 7 in a base station in accordance with an embodiment of the present invention.
- Figure 9a shows a flow chart of beamforming training in accordance with one embodiment of the present invention.
- Figure 9b shows a schematic diagram of beamforming training in accordance with one embodiment of the present invention.
- Figure 10a shows a flow chart of beamforming training in accordance with one embodiment of the present invention.
- Figure 10b shows a schematic diagram of beamforming training in accordance with one embodiment of the present invention.
- Figure 11 shows a flow chart of beamforming training in accordance with one embodiment of the present application.
- Figure 12a shows a flow chart of beamforming training in accordance with another embodiment of the present invention.
- Figure 12b shows a schematic diagram of beamforming training in accordance with another embodiment of the present invention.
- Figure 13a shows a flow chart of beamforming training in accordance with another embodiment of the present invention.
- Figure 13b shows a schematic diagram of beamforming training in accordance with another embodiment of the present invention.
- Figure 14a shows a flow chart of beamforming training in accordance with another embodiment of the present invention.
- Figure 14b shows a schematic diagram of beamforming training in accordance with another embodiment of the present invention.
- Figure 15 shows a flow chart of beamforming training in a multi-user millimeter wave system.
- Figure 16 shows a graph of user average reachability and signal to noise ratio in accordance with one embodiment of the present application.
- Figure 17 shows a graph of user average reachability and signal to noise ratio in accordance with one embodiment of the present application.
- Fig. 18 shows an example of a hardware configuration of an electronic device according to the present invention.
- each antenna is connected to one radio frequency link for transmission and reception.
- the data stream to be transmitted is first subjected to baseband processing, and then converted into a radio frequency signal via a radio frequency link to be transmitted through a corresponding antenna, and the corresponding radio link is received at the receiving end.
- the received RF signal is processed into a baseband signal and then further baseband processed to obtain the desired data stream.
- a digital precoding architecture in which each antenna is connected to one radio frequency link, and the amplitude of the signal is transmitted on each radio frequency link.
- the values are all adjustable to reduce interference between multiple data signals carried on the same transmission resource.
- Such processing before data is transmitted via the radio frequency link and antenna may be referred to as baseband digital processing of the data at the transmitting end.
- Figure 1 schematically illustrates a conceptual structure of a prior art base station.
- the base station is equipped with M antennas (M is an integer and M ⁇ 1), and each antenna is arranged with a corresponding radio frequency link.
- the digital precoder obtains a K-way data stream (K is an integer and K ⁇ 1) under the control of the controller, and digitally pre-codes the K-channel data stream (for example, causing the K-way data to flow through a size of M ⁇ K Digital precoding matrix B).
- K is an integer and K ⁇ 1
- the encoded data is transmitted to one or more users via a radio frequency link and an antenna.
- the client can have multiple configurations to perform corresponding baseband digital processing after receiving the encoded data over the radio frequency link to obtain the desired data stream.
- Figure 2 shows a client configured with a single antenna.
- the UE is provided with a single antenna and a corresponding single RF link. Since the client has only one antenna, it can only receive a single data stream. That is to say, in the K-channel data stream sent from the M antennas of the base station, only one data stream can be received by the UE through corresponding digital processing.
- Figure 3 shows a client configured with multiple antennas.
- the UE is configured with N antennas (N is an integer and N>1).
- N is an integer and N>1).
- Each antenna transmits the received data to a digital precoder through a corresponding radio frequency link.
- CSI Channel State Information
- the above digital precoding process can be considered to belong to the baseband digital processing portion in wireless communication.
- Analog beamforming training refers to a process of optimizing configuration information of a base station and a user equipment (for example, a configuration value of a phase shifter involving a base station and a user equipment, also referred to as a weight vector for a phase shifter), and its main function It is to improve the user's receiving signal to noise ratio.
- a base station forms a transmit beam having directivity by configuring values of a plurality of phase shifters connected to its plurality of antennas, and the user equipment configures values of a plurality of phase shifters connected to the plurality of antennas thereof.
- a receive beam having directivity is formed, and the transmit beam of the base station and the receive beam of the user equipment form a set of beam pairs of the downlink.
- the process of downlink beamforming training finds the process of an optimal set of beam pairs consisting of the optimal base station transmit beam and the optimal user equipment receive beam.
- the receive beam of the base station and the transmit beam of the user equipment also form a set of beam pairs.
- Millimeter wave communication systems have multiple modes of operation, such as point-to-point mode, single-user mode, multi-user mode, and the like.
- Point-to-point mode can be used for base station (BS) backhaul
- single-user mode and multi-user mode can be used for communication between a base station and one or more user equipments (UEs).
- the implementation architecture may include analog beamforming, full-connection analog-digital hybrid precoding, sub-connection analog-digital hybrid precoding, and the like.
- the configuration information of the base station and the user equipment for example, the configuration values of the phase shifters involving the base station and the user equipment
- the configuration information may be referred to as a weight vector, which generally refers to a configuration value (eg, a phase value) of the phase shifter.
- Such processing is mainly performed at the radio frequency portion of the transmitting end and the receiving end of the wireless communication system, and can be considered as radio frequency analog processing.
- FIG. 4a and 4b show the configuration of the base station and the client in a single-user system, respectively.
- each RF link is connected with a set of phase shifters, and each phase shifter is respectively connected to a corresponding antenna.
- the values of a set of phase shifters may be indicated by a set of configuration parameters, such as DFT vectors, also referred to as weight vectors or beam vectors.
- DFT vectors also referred to as weight vectors or beam vectors.
- a codebook is a collection of weight vectors. Let the base station codebook be F, the codebook size be P (including P weight vectors), the client codebook is W, and the codebook size is Q (including Q weight vectors), then the base station weight vector must be from the base station side. In the codebook F, the weight vector of the client must be selected from the client codebook W.
- Beam training may employ a maximum signal to noise ratio criterion to determine a weight vector used to form the optimal beam, which may be expressed as:
- H ⁇ N ⁇ M represents a downlink channel between the base station and the UE
- W is a candidate set (codebook) for the weight vector of the UE
- F is a candidate set (codebook) for the weight vector of the base station
- w opt , f opt are the determined optimal weight vectors for the UE and the base station, respectively.
- the millimeter-wave multipath channel Due to the large attenuation of the millimeter-wave channel path, the millimeter-wave multipath channel has a small number of scatterers, and the millimeter-wave channel H can usually be modeled as
- N and M respectively represent the number of antennas equipped by the UE and the base station
- N cl is the number of scatterers
- N ray is the number of sub-paths included in each scatterer
- ⁇ i, l represents the channel coefficient of the corresponding scatter path
- a The UE and a BS respectively represent the antenna response vectors of the UE and the base station
- ⁇ and ⁇ are the horizontal direction and the vertical direction of arrival, respectively.
- the antenna response vector is independent of the vertical angle of arrival ⁇ and can be expressed as
- ⁇ is the wavelength
- d is the antenna spacing
- N is the number of antennas.
- a millimeter-wave wireless communication system can also employ an analog-to-digital hybrid precoding architecture.
- 5a and 5b show the configuration of the base station side and the client side in the analog-digital hybrid precoding architecture, respectively.
- the base station end using the analog-digital hybrid precoding architecture has a baseband digital precoder and an analog phase shifting network.
- the baseband digital precoder obtains the K channel data stream as an input, and the baseband digital precoder performs digital precoding on the K channel data, thereby eliminating interference between different data streams.
- the K RF links perform up-conversion, amplification, filtering, and the like on the data stream pre-coded by the digital precoder to become a radio frequency signal.
- each radio link corresponds to one UE.
- K RF links are connected to the analog phase shifting network.
- the values of the individual phase shifters in the phase shifting network constitute the analog beamforming matrix F.
- the first column represents a set of values k phase shifters k-th radio link connection, expressed as a weight vector f k, f k be the weight vector selected from the codebook at the base station in f.
- Figures 6a and 6b show schematic diagrams of a fully connected phase shifting network and a sub-connected phase shifting network, respectively.
- each RF link in a fully connected phase-shifted network, is connected to a set of M phase shifters, so that there are K sets of phase shifters, the total number of phase shifters in the fully connected phase-shifted network. It is K ⁇ M.
- the signals (K signals) output from the corresponding phase shifters in each group of phase shifters are added by the adder and supplied to the corresponding antenna elements.
- each RF link in a fully connected phase shifting network, each RF link can be connected to all antennas via an analog phase shifter.
- each radio frequency link is connected to a portion of the antenna via an analog phase shifter. Usually the antennas are evenly distributed to K RF links.
- Figure 5b shows the configuration of the client using a hybrid precoding architecture.
- the UE is configured with N antennas, and the signal received by each antenna is input to the radio frequency link after passing through the corresponding phase shifter.
- Value of the respective phase shifters constituting the client weight vector w k the UE can select the right from the UE in the codebook weight vector W w k.
- the RF link filters, amplifies, and downconverts the input signal to obtain a digital received signal.
- the client has multiple radio links. According to the actual situation, it is also possible to adopt a design of an RF link on the user side.
- beam training is the process of determining the weight vector of the base station and the client from a predetermined codebook. Taking the following line transfer as an example, the maximum signal to noise ratio criterion can be expressed as:
- ⁇ w k,opt ,f k,opt ⁇ represents the k-th user-optimized downlink weight vector
- H k is the downlink channel matrix between the base station and the k-th user.
- the traditional beamforming training mechanism mainly includes physical channel estimation, exhaustive search, multiple feedback and single feedback.
- the physical channel estimation mechanism directly estimates the downlink physical channel through the pilot
- the UE calculates an optimal base station weight vector and a client weight vector according to the estimated physical channel, and feeds back the base station weight vector or the weight vector index to the base station.
- the channel estimation complexity is extremely high, and the pilot is not beamformed in the channel estimation process, resulting in lower reception signal and noise, and channel estimation accuracy. low.
- the exhaustive search mechanism searches for all possible combinations of the weight vector of the base station and the weight vector of the UE.
- the UE measures the channel quality under each pair of transmit/receive weight vectors, selects the optimal set from the best base station.
- the weight vector or base station weight vector index is fed back to the base station.
- the exhaustive search mechanism can achieve optimal performance, but the complexity is extremely high.
- the number of combinations of weight vectors that need to be searched is P ⁇ Q, where P and Q are the base station and client codebook sizes, respectively.
- the multiple feedback mechanism divides the training process into multiple layers through pre-designed multi-layer codebooks, using exhaustive search in each layer. Since the number of candidate codewords in each layer is small, the complexity is reduced.
- the number of weight vector combinations that need to be detected by the multiple feedback mechanism is P l and Q l are the size of the layer 1 codebook of the base station and the client, respectively, and L is the codebook layer.
- only a part of all combinations of the weight vector of the UE and the weight vector of the base station may be selected for detection.
- it may be a combination of a weight vector in the base station codebook and all weight vectors in the client codebook, or may be one of the weight vectors in the client codebook and all the weight vectors in the base station codebook. combination.
- the weight vector obtained in the combination of one of the weight vectors in the base station codebook and all the weight vectors in the client codebook may be selected in the weight vector in the client codebook.
- a specific example is the single feedback mechanism.
- the single feedback mechanism splits the beamforming training into two processes.
- the base station transmits a signal (for example, a pilot signal) according to each weight vector in the base station codebook, and the UE uses an omnidirectional beam (for example, the UE).
- a signal for example, a pilot signal
- the UE uses an omnidirectional beam (for example, the UE).
- Receiving and estimating a channel quality corresponding to each weight vector in the base station codebook by receiving a predetermined weight vector, such as using only one antenna in the antenna array, the UE The weight vector with the best channel quality is selected and the index is fed back to the base station.
- the base station fixedly uses the weight vector selected by the UE to transmit the signal, and the UE selects the weight vector with the highest channel quality from the codebook as the weight vector to be communicated with the base station (ie, calculates each weight vector in the client codebook).
- the complexity of the single feedback mechanism is greatly reduced.
- the number of weight vector combinations that need to be detected by the single feedback mechanism is P+Q, where P and Q are the base station and client codebook sizes, respectively.
- the beam training method is described above by taking the downlink transmission in a single user scenario as an example.
- the process performed in the uplink transmission process is basically similar.
- the main difference is that the UE sends a signal and the base station receives the signal.
- channel quality can be obtained by channel estimation. Through channel estimation, channel direction and channel quality can be obtained.
- the information indicating the channel quality for example, the CQI (Channel Quality Indicator) used in the LTE standard and the identification information of the corresponding parameter group (optimal weight vector index) may be included, and may also include the optimal multiple CQIs. Identification information of a parameter group corresponding to each CQI.
- the beam training method may employ the above-described exhaustive search, multiple feedback search, or single feedback search mechanism, or other multi-user beam search mechanism.
- the antennas of the base station and the UE are large in scale, and more candidate beams can be formed, and the corresponding base station codebook and the client codebook are also large.
- the beamforming training required by the existing exhaustive search, multiple feedback search or single feedback search mechanism is difficult to meet the practical application requirements.
- the Applicant has proposed an improved beamforming training scheme.
- multiple antennas can typically be arranged as a two-dimensional planar antenna array, in which case the antenna response vector can typically be decomposed into a combination of several sub-vectors.
- the weight vector for beamforming is also decomposed into sub-vectors corresponding to the sub-vector, so that training can be separately performed in the beamforming training, thereby obtaining each of the determined weight vectors.
- the sub-vectors, finally the desired weight vector can be determined by the combination of the determined sub-vectors.
- the antenna response Vector can be expressed as
- the codebook may also be F F F H and vertical V codebook using Keluoneike Product generation, ie Based on this, the present disclosure performs beamforming training in the horizontal and vertical domains by using the horizontal codebook and the vertical codebook constituting the huge analog codebook, respectively, and obtains the optimal horizontal direction weight vector and the vertical direction weight vector, and then reuses The Kronec product calculates the optimal weight vector trained.
- Cronet's product described above is illustrated as a preferred example for ease of implementation, and other suitable operations for decomposition and combination of codebooks are also possible, and similar effects can be achieved.
- an important point of the present invention is to split the training into two directions, without forcing constraints on the shape and codebook of the antenna, and possibly arranging the multiple antennas in other two-dimensional or three-dimensional manners (for example, a curved antenna array or a cylinder). In the case of a bulk antenna array, it can still be split into two directions to obtain the optimal first direction and second direction angle information, and the final optimal beam is calculated by using a specific signal processing algorithm.
- the codebook other suitable operations for the decomposition and combination of the codebook are also conceivable, and similar effects can still be achieved.
- the beam training algorithm proposed by the present invention is still applicable.
- a triangular or shaped antenna array even if the antenna response vector does not have a Kronenko product structure, since the antenna is still a two-dimensional or above antenna array, an appropriate phase shifter configuration value can be reasonably designed (may be based on The codebook may also be based on the codebook to make the antenna array of the triangle obtain the beams in the vertical direction and the horizontal direction, respectively, and perform beam training in the vertical direction and the horizontal direction respectively to obtain the direction of the specific user, and then the vertical and horizontal directions.
- the direction training results are subjected to a specific combination (a combination of non-Crenoenko product forms) to obtain an antenna array weight vector to configure the actual transmission.
- the base station transmits a plurality of beams that are horizontally omnidirectional and vertically directional, so that the vertical direction beam information can be obtained by scanning, or the vertical angle of arrival information of the channel can be visually understood.
- the base station transmits a plurality of beams in the vertical domain aligned with the direction determined in the first step and horizontally directional, so that the horizontal beam information is known by scanning, or the channel is intuitively Horizontal arrival angle information.
- the base station uses the horizontal beam information and the vertical beam information to synthesize the final beam for service through the signal processing algorithm. Furthermore, although the foregoing mentions the case where an appropriate codebook is selected as the optimal direction weight vector in the training codebook to configure the actual transmission, it should be noted that the basic idea of the present invention is still applicable to the final determined weight vector. In the case of training codebooks.
- the codebook having the Crohnenko product characteristic can be used for training, the codebook is vertical and horizontal. After the two parts are composed, the optimal weight vector obtained by the training is compared with the code word in the actual codebook to find the closest one for the actual transmission.
- the optimal weight vector dedicated to the training with the codebook having the Cronico product property can be used, and the optimal weight vector obtained from the training can be used.
- the suboptimal weight vector or other factors are interpolated and the like as the weight vector actually used.
- the complexity of the training method of the present application can generally be further reduced compared to existing beamforming training mechanisms.
- the number of weight vector combinations that need to be detected by the single feedback mechanism is P+Q, where P and Q are the base station and client codebook sizes, respectively.
- the present application provides a beamforming training method and an apparatus for implementing the same, wherein sub-configuration parameters are respectively determined and combined by decomposing configuration parameters (eg, weight vectors) to be determined into a plurality of sub-configuration parameters.
- the determined sub-configuration parameters are used to reconstruct the optimal configuration parameters for beamforming training.
- Such a training process can at least achieve similar performance to existing beamforming training, while the training overhead is significantly reduced.
- an electronic device for a first communication device in a wireless communication system wherein the communication device is arranged with a plurality of antennas.
- the electronic device can include processing circuitry configurable to respectively configure the first communication device to the first transmission of the second communication device in the wireless communication system based on the plurality of sets of first sub-configuration parameters such that the particular set of first a sub-configuration parameter is determined based on the first transmission-related information, wherein the plurality of sets of first sub-configuration parameters are associated with a first direction relative to a plane of the plurality of antennas; based on the plurality of sets of second sub-configuration parameters Separating the second transmission of the first communication device to the second communication device, respectively, such that a specific set of second sub-configuration parameters are determined based on the second transmission-related information, wherein the plurality of sets of second sub-configuration parameters are relative to A second direction of the plane is associated, the second direction being orthogonal to the first direction; and configuring a subsequent transmission by the first communication device to
- the first communication device may be a base station or a user equipment
- the second communication device may be a user equipment that communicates with the base station or a base station that communicates with the user equipment.
- a set of first configuration parameters for the first communication device is a phase value (ie, the aforementioned weight) for each phase shifter for configuring a set of phase shifters that correspond one-to-one with the plurality of antennas Vector), and a set of first configuration parameters can be decomposed into a set of first sub-configuration parameters and a set of second sub-configuration parameters, and can be combined by the set of first sub-configuration parameters and the second set of sub-configuration parameters of the set ( Can be an inverse of decomposition, for example, Croyne Cortex) was refactored.
- a particular set of first sub-configuration parameters and a particular set of second sub-configuration parameters can be separately determined from the candidate codebooks, respectively, thereby determining a particular set of first configuration parameters.
- Each of the plurality of sets of first sub-configuration parameters as the candidate codebook may be a phase value for configuring a plurality of phase shifters in a group of phase shifters corresponding to the plurality of antennas one by one, and
- Each of the plurality of sets of second sub-configuration parameters may be a phase value for configuring a plurality of phase shifters in the set of phase shifters.
- the plurality of phase shifters corresponding to the plurality of sets of first sub-configuration parameters and the plurality of phase shifters corresponding to the plurality of sets of second sub-configuration parameters may be different.
- the plurality of sets of first sub-configuration parameters may be associated with a first direction of the plurality of antennas, which may be referred to as a plurality of first direction weight vectors, and may be referred to as a first direction codebook.
- Each set of first sub-configuration parameters in the first-direction sub-codebook may be configured to provide a phase value of the generated signal by configuring a phase value of a group of phase shifters corresponding to the plurality of antennas of the base station. Distributed in one direction.
- the plurality of sets of second sub-configuration parameters may be associated with a second direction of the plurality of antennas, ie, a plurality of second direction weight vectors, and may be referred to as a second direction codebook.
- the first direction and the second direction may be planes relative to a plurality of antennas of the base station.
- Each set of second sub-configuration parameters in the second-direction sub-codebook can be configured to align the phase of the generated signal by configuring a phase value of a group of phase shifters corresponding to the plurality of antennas of the base station.
- Distributed in two directions may be Typically, the first direction may be a horizontal direction relative to a plane of the plurality of antennas of the base station, and the second direction may be a vertical direction perpendicular to a plane of the plurality of antennas. In other cases, the first direction may be a vertical direction and the second direction is a horizontal direction.
- the first direction and the second direction may also be other directions as long as they are orthogonal to each other.
- respectively configuring the first transmission based on the plurality of sets of first sub-configuration parameters may comprise configuring the first transmission based on the plurality of sets of first sub-configuration parameters and a predetermined set of second sub-configuration parameters.
- the predetermined set of second sub-configuration parameters may be predetermined by the wireless communication system.
- respectively configuring the second transmission based on the plurality of sets of second sub-configuration parameters may comprise configuring the second transmission based on the particular set of first sub-configuration parameters and the plurality of sets of second sub-configuration parameters.
- the first transmission related information may be information indicating a quality of the communication channel of the first transmission.
- such information may be obtained by channel estimation for transmission at the second communication device.
- such information may include a communication channel quality estimate for the first transmission corresponding to each set of first sub-configuration parameters, whereby a set of first self-configuration parameters corresponding to the optimal communication channel quality may be determined from the estimation result as A specific set of first sub-configuration parameters.
- the first transmission related information may further indicate a set of first sub-configuration parameters or an index of the set of first sub-configuration parameters that are optimal for the communication channel quality of the first transmission. In the latter case, it can be found from multiple sets of first sub-configuration parameters stored or obtained in advance. A set of first sub-configuration parameters corresponding to the index.
- Such information may be obtained by a second communication device in communication with the first communication device or obtained by other devices than the first communication device and the second communication device, and a particular set of first sub-configuration parameters may be obtained by the second communication device or Other devices are determined and provided to the first communication device, or may be determined by the processing circuitry of the first communication device based on such information being provided, or may be based on such information being provided by other circuitry of the first communication device To determine and provide to the processing circuit.
- the second transmission related information may be information indicating a quality of a communication channel of the second transmission. This information may be similar to the information related to the first transmission, and a particular set of second sub-configuration parameters may be obtained in a manner similar to a particular set of first sub-configuration parameters. Therefore, a detailed description of the second transmission related information is omitted here.
- the particular set of first configuration parameters may be determined by a combination of a particular set of first sub-configuration parameters and a particular set of second sub-configuration parameters (eg, Cronet's product).
- the particular set of first configuration parameters may be determined by a processing circuit of the first communication device, or determined by a device other than the processing circuit of the first communication device and provided to the processing circuit, or may be external to the first communication device A device (eg, a second communication device or other communication device) is determined and provided to the processing circuit.
- a method for a wireless communication system is also provided, wherein the wireless communication system includes a first communication device and a second communication device, the first communication device being arranged with a plurality of antennas, the method
- the first transmission of the first communication device to the second communication device is respectively configured based on the plurality of sets of first sub-configuration parameters, such that a specific set of first sub-configuration parameters are determined based on the first transmission-related information, wherein the plurality of The first sub-configuration parameter is associated with a first direction relative to a plane of the plurality of antennas;
- the second transmission of the first communication device to the second communication device is respectively configured based on the plurality of sets of second sub-configuration parameters, such that a specific one Group second sub-configuration parameters are determined based on the second transmission-related information, wherein the plurality of sets of second sub-configuration parameters are associated with a second direction relative to the plane, the second direction and the first direction Orthogonalizing; and configuring subsequent transmissions by the first communication device to the second communication
- Such a method may be implemented by a first communication device in a wireless communication system or by other devices than the first and second communication devices in the wireless communication system.
- Figure 7a shows the base station with processing circuitry 701, and optional weight vector synthesis unit 702 and memory 703, as indicated by the dashed boxes in the figures. Should It is pointed out that such description is by way of example only and not as a limitation.
- the plurality of sets of the first group of sub-configuration parameters (the first direction sub-codebook) and the plurality of sets of the second group of sub-configuration parameters (the second-direction sub-codebook) may be pre-stored in the memory 703 of the first communication device, Or derived from a plurality of sets of first configuration parameters 703 pre-stored in a memory of the first communication device. It should be noted that the memory 703 is not necessary for the first communication device 700.
- the first direction subcodebook and the second direction subcodebook may pass some parameters (eg, the size of the antenna array) by the first communication device. It may be determined directly or, alternatively, may be provided from outside the first communication device.
- the processing circuit 701 can be configured to configure signal transmission of the base station such that beamforming training between the base station and the user equipment is performed based on the first direction subcodebook and the second direction subcodebook of the base station.
- the base station transmits a signal (eg, a pilot signal or a reference signal, a training signal) based on the first direction subcodebook to communicate with the user equipment, and the user equipment according to
- the signal transmitted by the base station performs channel estimation such that a first direction weight vector (ie, a preferred set of first sub-configurations for the phase shifter) that is optimal for communication (eg, optimal communication channel quality) can be determined based on the estimate. parameter).
- a first direction weight vector ie, a preferred set of first sub-configurations for the phase shifter
- the base station transmits a signal (eg, a pilot signal or a reference signal, a training signal) based on the second direction subcodebook to communicate with the user equipment, and the user equipment according to the base station
- a signal eg, a pilot signal or a reference signal, a training signal
- the transmitted signal is used for channel estimation such that a second direction weight vector (ie, a particular set of second sub-configuration parameters) that is optimal for communication (eg, communication channel quality is optimal) can be determined.
- the sub-configuration parameters may be determined by the user equipment and provided to the base station as communication-related information, or may be determined and provided to the base station based on the estimation results by other means than the base station and the user equipment. Alternatively, the estimation result may be provided by the user equipment to the base station to determine the sub-configuration parameters at the base station.
- the optimal weight vector for the base station i.e., a particular set of first configuration parameters
- the optimal weight vector for the base station is obtained by their particular combination for configuring the phase values of the individual phase shifters in a set of phase shifters. This particular combination may for example be Kronenko.
- the determination of the optimal weight vector may be performed at a first communication device (e.g., a base station), such as by processing circuit 701, or by weight vector synthesis unit 702 outside of the processing circuit, although weight vector synthesis unit 702 is optional. of.
- the optimal weight vector may be determined by the user equipment or determined by other means than the user equipment and provided to the first communication device.
- an electronic device for a second communication device of a wireless communication system includes a processing circuit configured to acquire a first group based on a plurality of groups by the first communication device The first transmission related information respectively configured by the sub configuration parameters, wherein the plurality of sets of first sub-configuration parameters are associated with a first direction relative to a plane of the plurality of antennas of the first communication device; and the acquisition is based on the first communication device Generating second transmission related information respectively configured by the second sub-configuration parameter, the plurality of second sub-configuration parameters being associated with a second direction relative to the plane, the second direction being orthogonal to the first direction;
- determining, according to a specific set of first sub-configuration parameters determined based on the first transmission-related information and a specific set of second sub-configuration parameters determined based on the second transmission-related information is configured to configure the first A particular set of first configuration parameters of a subsequent transmission by the communication device to the second communication device.
- the acquired transmission related information may be obtained by the second communication device by channel estimation for transmission, or by other devices than the first communication device and the second communication device by channel estimation for transmission and Provided to the second communication device.
- the acquisition of information by the electronic device can be performed in a variety of ways.
- acquiring first transmission related information respectively configured by the first communication device based on the plurality of sets of first sub-configuration parameters may include acquiring, by the first communication device, the plurality of sets of first sub-configuration parameters and a predetermined set of Information of communication channel quality of the first transmission configured by the two sub-configuration parameters; wherein the specific set of first sub-configuration parameters is a set of first sub-configuration parameters that optimize the quality of the communication channel of the first transmission.
- acquiring second transmission related information respectively configured by the first communication device based on the plurality of sets of second sub-configuration parameters comprises obtaining, by the first communication device, the first set of first sub-configuration parameters and the plurality of groups of second Sub-configuration parameters to configure information of the communication quality of the second transmission; wherein the specific set of second sub-configuration parameters is a set of second sub-configurations that optimize communication channel quality of the first transmission parameter.
- the above-described communication channel quality information may be obtained by the second communication device itself, for example directly by the processing circuit or obtained by other components in the second communication device and provided to the processing circuit, or may be external to the second communication device.
- the device is obtained and provided to the second communication device.
- Figure 7b shows a schematic diagram of an electronic device for another communication device in a wireless communication system, in accordance with one embodiment of the present invention.
- the other communication device is for communicating with the communication device of Figure 7a.
- the other electronic device 710 of Figure 7b is a user device.
- the other electronic device 710 of Figure 7b is a base station. The following is an example in which the electronic device of FIG. 7b is located in the user equipment.
- the electronic device 710 can include a memory 711 and a processing circuit 712.
- the memory 711 can be used to store the analog codebook of the base station and/or the first as the memory 703 in FIG. 7a.
- Direction subcodebook and second direction subcodebook The analog codebook of the base station and/or the first direction subcodebook and the second direction subcodebook may be transmitted by the base station to the electronic device 710.
- the base station may also only send some device parameters of the base station (for example, the size of the antenna array), and the electronic device 710 may determine an analog codebook and/or a first direction subcodebook for the base station based on the device parameters.
- the second direction subcodebook Like memory 703, this memory 711 is also not required for electronic device 710.
- the processing circuit 712 may perform channel estimation on the signal transmission (first transmission) transmitted by the base station based on the first direction subcodebook, and send feedback of the channel estimation result to the base station, so that the base station determines the optimal first.
- Direction weight vector ie, a specific set of first sub-configuration parameters.
- the feedback of the channel estimation result may be a first direction weight vector in the first direction subcodebook that makes the communication channel quality optimal or an index of the first direction weight vector.
- the feedback of the channel estimation result may be only the channel estimation result itself, and the base station determines the first direction weight vector corresponding to the optimal communication channel quality according to the received channel estimation result.
- the feedback of the channel estimation result may also be provided to other devices than the base station and the user equipment to determine the first direction weight vector, and the determined first direction weight vector is then provided to the first communication device.
- the processing circuit 712 can also perform channel estimation according to the signal transmission (second transmission) sent by the base station based on the second direction subcodebook, and feed back the result of the channel estimation to the base station, so that the base station determines the optimal second direction weight vector (That is, a specific set of second sub-configuration parameters).
- the feedback of the channel estimation result may be an index of a second direction weight vector or a second direction weight vector that makes the communication channel quality optimal in the second direction subcodebook.
- the feedback of the channel estimation result may be only the channel estimation result itself, and the base station determines a second direction weight vector corresponding to the optimal communication channel quality according to the received channel estimation result.
- the feedback of the channel estimation result may also be provided to other devices than the base station and the user equipment to determine the second direction weight vector, and the determined second direction weight vector is then provided to the first communication device.
- the optimal direction weight vector obtained by combining the first direction weight vector and the second direction weight vector may also be determined by the user equipment and provided to the base station, which may be determined by the base station itself, or may be determined by devices other than the user equipment and the base station. Provided to the base station.
- a method for a wireless communication system comprising Acquiring first transmission related information respectively configured by the first communication device based on the plurality of sets of first sub-configuration parameters, wherein the plurality of sets of first sub-configuration parameters are related to a first direction of a plane of the plurality of antennas relative to the first communication device Union And acquiring second transmission related information respectively configured by the first communication device based on the plurality of sets of second sub-configuration parameters, the plurality of sets of second sub-configuration parameters being associated with a second direction relative to the plane, the The two directions are orthogonal to the first direction; wherein the specific set of first sub-configuration parameters determined based on the first transmission related information and the specific set of second determined based on the second transmission related information The sub-configuration parameters determine a particular set of first configuration parameters for configuring subsequent transmissions by the first communication device to
- FIG. 8 illustrates beamforming training using the electronic devices of FIGS. 7a and 7b in a base station in accordance with an embodiment of the present invention.
- the base station indicates to the user equipment a first direction beamforming training parameter, for example, training sequence indication information for the user equipment, start time and end time of the first direction beamforming training. (for example, the subframe number), the number of transmissions of the training sequence, and the like.
- a first direction beamforming training parameter for example, training sequence indication information for the user equipment, start time and end time of the first direction beamforming training. (for example, the subframe number), the number of transmissions of the training sequence, and the like.
- the base station transmits a training sequence to the user based on the first direction subcodebook for first direction beamforming training. Specifically, the base station repeatedly transmits the training sequence based on each of the first direction weight vectors (each set of first sub-configuration parameters) in the first direction subcodebook.
- the user equipment uses processing circuitry 712 to perform channel estimation based on the training sequence and to transmit feedback of the channel estimation results to the base station.
- the feedback of the channel estimation result is, for example, a first direction weight vector (a specific set of first sub-configuration parameters) in the first direction sub-codebook that makes the communication channel quality optimal, or an index of the first direction weight vector. Or simply the channel estimation result itself.
- the base station indicates the second direction beamforming training parameter to the user equipment, for example, the start time and the end time of the second direction beamforming training (for example, the subframe number), the number of times the training sequence is sent, and the like.
- the base station transmits a training sequence to the user based on the second direction subcodebook for second direction beamforming training. Specifically, the base station repeatedly transmits the training sequence based on each second direction weight vector (each set of second sub-configuration parameters) in the second direction sub-codebook.
- the user equipment uses processing circuitry 712 to perform channel estimation based on the training sequence and to transmit feedback of the channel estimation results to the base station.
- the feedback of the channel estimation result is, for example, a second direction weight vector (a specific set of second sub-configuration parameters) in the second direction sub-codebook that makes the communication channel quality optimal, or an index of the second direction weight vector. Or simply the channel estimation result itself.
- the base station obtains the most by a specific combination based on the optimal first direction weight vector (a specific set of first sub-configuration parameters) and the optimal second direction weight vector (a specific set of second sub-configuration parameters). Excellent weight vector (a specific set of first configuration parameters).
- the base station performing the first direction beamforming training or transmitting the training sequence to the user based on the first direction subcodebook includes: the base station is based on each first direction weight in the first direction subcodebook.
- the vector is combined with a Kronenko product of a certain second direction weight vector to obtain a plurality of sets of first configuration parameters for setting phase values of a group of phase shifters corresponding to the plurality of antennas of the base station for transmission.
- the second direction weight vector may be a weight vector corresponding to the second direction omnidirectional beam, or may be a known second direction weight vector.
- the base station performs the second direction beamforming training or sends the training sequence to the user based on the second direction subcodebook.
- the implementation also includes: the base station is based on each second direction weight vector in the second direction subcodebook.
- the Kronec product of the first direction weight vector is combined to obtain multiple sets of first configuration parameters, and then beamforming training is performed.
- the Krones product synthesis step therein is not specifically indicated below when describing the beamforming training of the base station or the user equipment in one direction.
- steps 801 and 804 described above may be combined into a single step, for example, in step 801, the base station may indicate to the user equipment a first directional beamforming training parameter and a second directional beamforming training parameter.
- the implementation of the two steps 801 and 804 can be combined into one signaling, which is sent to the user in the first step of training, and of course the two steps 801 and 804 are also performed independently in two directions. Separate as separate instructions.
- this configuration signaling is dedicated signaling, such as implemented as radio resource control signaling to personalize the configuration for individual users.
- FIG. 8 is merely an example and is not intended to be limiting. It should be noted that some implementations in the process described with respect to FIG. 8, such as a particular set of first sub-configuration parameters, a particular set of second sub-configuration parameters, and a particular set of first configuration parameters may be determined as described above. Make an alternative implementation.
- Figure 8 primarily illustrates a flow diagram utilizing the beamforming training mechanism of the present invention when the first communication device (e.g., base station side) has multiple antennas, particularly two-dimensional planar array antennas (UPAs).
- a second communication device e.g., user equipment
- a specific set of configuration parameters for the second communication device ie, for the second communication
- a training sequence e.g, a pilot signal
- the optimal receive weight vector of the device also needs to be determined, for example, by receiving, from the second communication device, each receive weight vector selection in the analog codebook such that the signal from the first communication device can obtain the best channel quality.
- This process is also referred to hereinafter as receive beam sweeping or receive weight vector scan. After receiving beam scanning, the user equipment can fix the subsequent communication with the optimal receiving weight vector.
- the second communication device is configured to receive the first pass from the plurality of sets of second configuration parameters
- the signal transmission of the signaling device, such reception may correspond to a receive beam scan or a receive weight vector scan.
- a particular set of second configuration parameters for configuring the second communication device is determined based on the signal related information.
- the signal transmission related information is information indicating a quality of a communication channel of the signal transmission
- the specific set of second configuration parameters is a group that optimizes a communication channel quality of the signal transmission The second configuration parameter.
- a particular set of second configuration parameters may be determined at the second communication device or determined by devices other than the second communication device and fed back to the second communication device.
- the signal transmission may be prior to the first transmission and the second transmission, for example, prior to the first direction beamforming training in step 802 of FIG. 8, and in this case, the first communication device may be based on The signal transmission is configured by a predetermined set of first configuration parameters.
- the signal transmission may be after the first transmission and the second transmission, for example after the second direction beamforming training in step 805 of FIG. 8, and in this case, the first communication device may be based on The signal transmission is configured by the determined particular set of first sub-configuration parameters and the determined particular set of second sub-configuration parameters.
- the signal transmission may be between the first transmission and the second transmission, for example, the first direction beamforming training in step 802 of FIG. 8 and the second direction beam in step 805 of FIG.
- the first communication device can configure the signal transmission based on the particular set of first sub-configuration parameters and a predetermined set of second sub-configuration parameters.
- the signal transmission may be the first transmission, for example, may be performed simultaneously with the first directional beamforming training in step 802 of FIG. 8, and in this case, the particular set of second configurations
- the parameter may be determined by configuring the first transmission with each of the plurality of sets of first sub-configuration parameters at the first communication device and employing each of the plurality of sets of second configuration parameters with the second communication device In a case where the first transmission is sequentially received, a set of second configuration parameters that optimize the channel communication quality of the corresponding first transmission is selected as the specific set of second configuration parameters.
- the signal transmission may be the second transmission, for example, may be performed simultaneously with the second direction beamforming training in step 805 of FIG. 8, and in this case, the particular set of second configurations
- the parameter may be determined by configuring the second transmission with each of the plurality of sets of second sub-configuration parameters at the first communication device and employing each of the plurality of sets of second configuration parameters with the second communication device
- a set of second configuration parameters that optimizes the quality of the communication channel of the corresponding second transmission is selected. The number is used as the specific set of second configuration parameters.
- the multiple antennas of the second communication device may also be two-dimensional planar array antennas.
- the second configuration parameter for the second communication device can also be decomposed into several sub-configuration parameters, and each sub-configuration parameter can be determined separately and the determined sub-configuration can be combined. Parameters to reconstruct the optimal second configuration parameter
- the particular set of second configuration parameters of the second communication device are derived from a particular set of third sub-configuration parameters and a particular set of fourth sub-configuration parameters, the third sub-configuration parameters and The four sub-configuration parameters are respectively associated with a third direction and a fourth direction of a plane corresponding to the plurality of antennas of the second communication device, and the third direction and the fourth direction are perpendicular, wherein the particular group of third sub- The configuration parameter is determined by the second communication device receiving a signal transmission from the first communication device based on the plurality of sets of third sub-configuration parameters and determining a set of third sub-configuration parameters that optimize the quality of the communication channel of the signal transmission,
- the specific set of fourth sub-configuration parameters is that the second communication device receives the signal transmission from the first communication device based on the determined set of third sub-configuration parameters and the plurality of sets of fourth sub-configuration parameters and determines that The signal transmission is determined by a set of fourth sub-configuration parameters that are optimal for the
- the above-described beamforming process for the second configuration parameter of the second communication device will be described below with reference to Figs. 9-14, respectively.
- Such a description is made on the premise that the first communication device is a base station and the second communication device is a user equipment, and it should be noted that such description is merely exemplary and not limiting.
- the omni-direction beams, horizontal omnidirectional beams, and vertical omnidirectional beams will be described.
- the omnidirectional beam has substantially the same gain at all horizontal and vertical angles of arrival, which can be expressed, for example, as:
- f omni [1,0,...,0] T ⁇ C N ⁇ 1 , where N is the number of antennas.
- the horizontal omnidirectional beam has substantially the same gain at all horizontal arrival angles and can be expressed, for example, as:
- C( ⁇ ) is a function of the vertical angle of arrival ⁇
- f v is an arbitrary vertical beam
- a typical horizontal omnidirectional beam example is f h
- omni [1,0,...,0] T ⁇ C W ⁇ 1 , where W is the number of antennas in the horizontal direction.
- the vertical omnidirectional beam has substantially the same gain at all vertical arrival angles. It can be expressed, for example, as:
- C( ⁇ ) is a function of the horizontal arrival angle ⁇
- f h is an arbitrary horizontal beam
- the predetermined set of first configuration parameters described above may correspond to the omnidirectional beam
- the predetermined set of second sub-configuration parameters described above may correspond to a horizontal omnidirectional beam or a vertical omnidirectional beam.
- Figure 9a shows a flow diagram of beamforming training in accordance with one embodiment of the present invention, wherein the user's receive beam scan is prior to the first direction beamforming training of the base station (i.e., the first transmission described above) .
- the base station repeats using an omnidirectional beam (ie, a predetermined set of first configuration parameters corresponding to a predetermined set of first sub-configuration parameters and a predetermined set of second sub-configuration parameters).
- a downlink training sequence is sent to scan the weight vector in the user's analog codebook.
- the number of transmissions of the training sequence may depend on the size of the user's analog codebook. For example, if the analog codebook of the user equipment includes Q weight vectors (ie, the analog codebook size of the user equipment is Q), the number of times the beamforming training sequence needs to be transmitted is greater than or equal to Q.
- the user equipment estimates an equivalent channel based on the received training sequence and calculates an optimal receive weight vector for the user equipment.
- the optimal reception weight vector may be a weight vector in the analog codebook of the user equipment that makes the channel quality the best. This can be expressed as follows:
- f omni is an omnidirectional beam and w opt is an optimal receiving weight vector.
- the user equipment will select the optimal receive weight vector as the receive weight vector to be used in subsequent transmissions (ie, a particular set of second configuration parameters).
- the base station uses a horizontal omnidirectional beam (ie, a predetermined set of second sub-configuration parameters) to scan the weight vector in the vertical direction subcodebook of the base station (ie, the plurality of first sub-configuration parameters), and repeats
- the downlink training sequence is transmitted, and the user receives the received weight vector determined in step 902.
- the number of transmissions of the training sequence may depend on the size of the vertical direction subcodebook of the base station. For example, if the vertical direction subcodebook of the user equipment includes H weight vectors (ie, the vertical direction subcodebook size of the user equipment is H), the number of times the beamforming training sequence needs to be transmitted is equal to H.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal vertical direction weight vector for the base station (ie, a particular set of first sub-configuration parameters).
- the optimal vertical direction weight vector may be a vertical direction weight vector in the vertical direction subcodebook of the base station that makes the channel quality the best. It can be expressed as:
- f h omni is a horizontal omnidirectional beam
- w opt is a received beam trained in S41
- f v, opt is an optimal vertical beam
- the user transmits the optimal vertical direction weight vector determined in step 904 as feedback of the channel estimation result to the base station.
- the feedback of the channel estimation result may be an optimal vertical direction weight vector itself or an index of the optimal vertical direction weight vector.
- the feedback of the channel estimation result may also be only the channel estimation result itself corresponding to each weight vector in the vertical direction subcodebook of the base station, and the base station determines the optimal vertical direction after receiving such feedback. Weight vector.
- the base station scans the weight vector in the horizontal subcodebook (ie, the plurality of second sub-configuration parameters) by using the optimal vertical direction weight vector determined in step 904, and repeatedly transmits the downlink training sequence, and the user still Reception is performed using the optimal receive weight vector determined in step 902.
- the number of transmissions of the training sequence may depend on the size of the horizontal direction subcodebook of the base station. For example, if the horizontal direction subcodebook of the user equipment includes W weight vectors (ie, the horizontal direction subcodebook size of the user equipment is W), the number of times the beamforming training sequence needs to be transmitted is equal to W.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal horizontal direction weight vector for the base station (ie, a particular set of second sub-configuration parameters).
- the optimal horizontal direction weight vector may be a horizontal direction weight vector in the horizontal direction subcodebook of the base station that makes the channel quality the best. It can be expressed as:
- w opt is the received beam trained in step 902
- f v opt is the vertical direction weight vector trained in step 904
- f h opt is the optimal horizontal direction weight vector.
- the user transmits the optimal horizontal direction weight vector determined in step 907 as feedback of the channel estimation result to the base station.
- the feedback of the channel estimation result may be the optimal horizontal direction weight vector itself or its index, or may be the channel estimation result itself.
- the base station obtains an optimal weight vector (ie, a specific one based on the optimal vertical direction received vector determined in step 904 and the optimal horizontal direction received weight vector determined in step 907 using Kronenko product synthesis.
- Group first configuration parameter ie
- the downlink beamforming training between the base station and the user equipment is completed, and the required number of training sequence transmissions is Q+H+W.
- the number of sequence transmissions is P+Q. It can be seen that the beamforming of the present invention is adopted compared to the conventional beamforming training mechanism. Training mechanisms can greatly reduce training costs.
- the base station first performs vertical beam scanning and then horizontal beam scanning, but it should be recognized that the base station can also perform horizontal beam scanning first and then vertical beam scanning.
- the process at this time is basically the same as that of FIG. 9a, except that in step 903, the base station uses the vertical omnidirectional beam to scan the weight vector in the horizontal direction subcodebook, which is not described herein.
- Figure 9b shows a schematic diagram of steps 901 (flow 1), 903 (flow 2) and 906 (flow 3) of Figure 9a. That is, the process 1 indicates that the base station uses omnidirectional beam transmission, and the user equipment performs reception beam scanning; the process 2 indicates that the base station uses the horizontal omnidirectional beam for vertical beam scanning, and the user equipment adopts a fixed optimal receiving beam; 3 indicates that the base station uses the optimal vertical beam for horizontal beam scanning, and the user equipment uses a fixed optimal receiving beam.
- the base station employs omnidirectional beam transmission without providing beamforming gain, which will affect the receive beam training of the user equipment to some extent.
- the base station may transmit a wide beam in a corresponding direction to provide a certain beamforming, for example, according to a user's rough orientation (eg, obtained by existing direction of arrival angle estimation, LBS, etc., or GPS information).
- Gain to assist the user in receiving beam scans may refer to a range in which the gain of the beam is concentrated over all possible values of the horizontal and vertical angles of arrival.
- the base station transmits an omnidirectional beam for training, this does not provide beamforming gain, which may sometimes affect beam training at the user equipment. Therefore, as a variant embodiment, it may be considered to first train the beam at the base station and then train the beam at the user equipment. This will be described in further detail below.
- Figure 10a illustrates a flow diagram of beamforming training in accordance with one embodiment of the present invention in which a user's receive beam scan is in a first direction beamforming training of the base station (i.e., the first transmission described above) and The second direction beamforming training (ie, the second transmission described above).
- the base station uses a horizontal omnidirectional beam to scan the weight vector in the vertical subcodebook of the base station, and repeatedly transmits the downlink training sequence, and the user uses the omnidirectional beam to receive.
- the number of transmissions of the training sequence may depend on the size of the vertical direction subcodebook of the base station. For example, if the vertical direction subcodebook of the user equipment includes H weight vectors (ie, the vertical direction subcodebook size of the user equipment is H), the number of times the beamforming training sequence needs to be transmitted is equal to H.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal vertical direction weight vector for the base station.
- the optimal vertical direction weight vector may be a channel quality in a vertical direction subcodebook of the base station The best amount of a vertical direction weight vector. It can be expressed as:
- f h omni is a horizontal omnidirectional beam
- w omni is an omnidirectional receiving beam
- f v, opt is an optimal vertical direction weight vector
- the user transmits the optimal vertical direction weight vector determined in step 1002 as feedback of the channel estimation result to the base station.
- the feedback of the channel estimation result may be the optimal vertical direction weight vector itself or its index. In some cases, the feedback of the channel estimation result may also be only the channel estimation result itself corresponding to each weight vector in the vertical direction subcodebook of the base station, and the base station determines the optimal vertical direction after receiving such feedback. Weight vector.
- the base station repeatedly transmits the downlink training sequence using the horizontal omnidirectional beam and the optimal vertical direction weight vector determined in step 1002 to scan the weight vector in the user's analog codebook.
- the number of transmissions of the training sequence may depend on the size of the user's analog codebook. For example, if the analog codebook of the user equipment includes Q weight vectors (ie, the analog codebook size of the user equipment is Q), the number of times the beamforming training sequence needs to be transmitted is equal to Q.
- the user equipment estimates an equivalent channel based on the received training sequence and calculates an optimal receive weight vector for the user equipment.
- the optimal reception weight vector may be a weight vector in the analog codebook of the user equipment that makes the channel quality the best. This can be expressed as follows:
- f h omni is a horizontal omnidirectional beam
- f v opt is the vertical beam trained in step 1002
- w opt is the optimal receiving beam
- step 1005 the user equipment will select the optimal receive weight vector as the receive weight vector to be used in subsequent transmissions.
- the base station scans the weight vector in the horizontal direction subcodebook using the optimal vertical direction weight vector determined in step 1002, and repeatedly transmits the downlink training sequence, and the user adopts the optimal receiving weight vector determined in step 1005.
- the number of transmissions of the training sequence may depend on the size of the horizontal direction subcodebook of the base station. For example, if the horizontal direction subcodebook of the user equipment includes W weight vectors (ie, the horizontal direction subcodebook size of the user equipment is W), the number of times the beamforming training sequence needs to be transmitted is equal to W.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal horizontal direction weight vector for the base station.
- the optimal horizontal direction weight vector may be a horizontal direction weight vector in the horizontal direction subcodebook of the base station that makes the channel quality the best. It can be expressed as:
- w opt is the received beam trained in step 1005
- f v,opt is the vertical direction weight vector trained in step 1002
- f h, opt is the optimal horizontal direction weight vector.
- the user transmits the optimal horizontal direction weight vector determined in step 1007 as feedback of the channel estimation result to the base station.
- the feedback of the channel estimation result may be the optimal horizontal direction weight vector itself or its index, or may be the channel estimation result itself.
- the base station obtains the optimal weight vector using Kronenko product synthesis based on the optimal vertical direction reception vector determined in step 1002 and the optimal horizontal direction reception weight vector determined in step 1007.
- the beamforming training mechanism of the present invention can greatly reduce the training overhead.
- the base station first performs vertical beam scanning and then horizontal beam scanning, but it should be recognized that the base station can also perform horizontal beam scanning first and then vertical beam scanning. Do not repeat them.
- Figure 10b shows a schematic diagram of steps 1001 (flow 1), 1004 (flow 2) and 1006 (flow 3) in Figure 10a. That is, the process 1 indicates that the base station uses the horizontal omnidirectional beam for vertical beam scanning, and the user equipment uses omnidirectional beam reception; the process 2 indicates that the base station uses the horizontal omnidirectional beam optimal vertical beam, and the user equipment scans the receiving beam; The process 3 shows that the base station uses the optimal vertical beam for horizontal beam scanning, and the user equipment uses a fixed optimal receiving beam.
- FIG. 11 shows a flow chart of beamforming training in accordance with an embodiment of the present invention in which a user's receive beam scans a first direction beamforming training at the base station (ie, the first transmission described above) and The second direction beamforming training (ie, the second transmission described above).
- the base station uses a horizontal omnidirectional beam to scan the weight vector in the vertical direction subcodebook of the base station, and repeatedly transmits the downlink training sequence, and the user uses omnidirectional beam reception.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal vertical direction weight vector for the base station.
- the user transmits the optimal vertical direction weight vector determined in step 1102 to the base station as feedback of the channel estimation result.
- the base station uses the optimal vertical direction weight vector determined in step 1102, the scan level The weighting vector in the direction subcodebook repeatedly transmits the downlink training sequence, and the user still receives the omnidirectional beam.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal horizontal direction weight vector for the base station.
- the user transmits the optimal horizontal direction weight vector determined in step 1105 as feedback of the channel estimation result to the base station.
- the base station obtains the optimal weight vector using Kronenko product synthesis based on the optimal vertical direction reception vector determined in step 1102 and the optimal horizontal direction reception weight vector determined in step 1105.
- the base station repeatedly transmits the downlink training sequence using the optimal weight vector obtained in step 1107 to scan the weight vector in the user's analog codebook.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal receive weight vector for the user.
- the training overhead required by the beamforming training mechanism of FIG. 11 is the same as that of the beam training mechanisms of FIGS. 9 and 10, and is much smaller than the training overhead of the conventional beamforming training mechanism.
- Figures 9-11 are merely an example and is not intended to be limiting. It should be noted that some implementations in the processes described with respect to Figures 9-11, such as a particular set of first sub-configuration parameters, a particular set of second sub-configuration parameters, and a particular set of first configuration parameters may be determined as described above Alternate implementation is done in that way.
- Figure 12a illustrates a flow diagram of beamforming training in which a user's receive beam scan is performed simultaneously in a first direction beamforming training of a base station, in accordance with one embodiment of the present invention.
- the first direction is the horizontal direction and the second direction is the vertical direction.
- the base station adopts a vertical omnidirectional beam, and scans the weight vector in the horizontal direction subcodebook of the base station and the weight vector in the analog codebook of the user, and repeatedly transmits the downlink training sequence.
- the number of transmissions of the training sequence may depend on the horizontal direction subcodebook of the base station and the size of the analog codebook of the user equipment. For example, if the horizontal direction subcodebook of the base station includes W weight vectors (ie, the horizontal direction subcodebook size of the base station is W), the analog codebook of the user equipment includes Q weight vectors (ie, the analog codebook of the user equipment). Size is Q), then wave The number of times the beam shaping training sequence needs to be transmitted is equal to W ⁇ Q.
- the user estimates an equivalent channel based on the received training sequence and calculates a combination of optimal weight vectors. That is to say, according to the training sequence, the user can calculate which combination of each weight vector in the horizontal direction subcodebook of the base station and each weight vector in the analog codebook of the user equipment can achieve The best channel quality. Through this calculation, the user can obtain the optimal horizontal direction weight vector of the base station and the optimal reception weight vector of the user. In subsequent transmissions, the base station and the user equipment will transmit using the selected pair of weight vectors. Expressed as a formula
- f v omni is a vertical omnidirectional beam
- w opt is the user's optimal receiving weight vector
- f h, opt is the optimal horizontal direction weight vector of the base station.
- the user determines the optimal horizontal direction weight vector determined in step 1202 as feedback of the channel estimation result to the base station.
- the base station scans the weight vector in the vertical direction subcodebook of the base station by using the optimal horizontal direction weight vector determined in step 1202, and repeatedly transmits the downlink training sequence, and the user determines the optimal weight vector in step 1202. Receive.
- the number of transmissions of the training sequence may depend on the size of the vertical direction subcodebook of the base station. For example, if the vertical direction subcodebook of the base station includes H weight vectors (ie, the vertical direction subcodebook size of the base station is H), the number of times the beamforming training sequence needs to be transmitted is equal to H.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal vertical direction weight vector for the base station. That is to say, according to the training sequence, the user can calculate which of the vertical direction weight vectors in the vertical direction subcodebook of the base station can achieve the best channel quality. It can be expressed as:
- w opt is the received weight vector trained in step 1202
- f h opt is the optimal horizontal direction weight vector of the base station trained in step 1202
- f v opt is the optimal vertical direction weight vector of the base station.
- the user transmits the optimal vertical direction weight vector of the base station determined in step 1205 as feedback of the channel estimation result to the base station.
- the base station obtains the optimal weight vector using the Kroneico product synthesis based on the optimal horizontal direction reception vector determined in step 1202 and the optimal vertical direction reception weight vector determined in step 1205 for use in pairing Subsequent transmission of the user equipment.
- the downlink beamforming training between the base station and the user equipment has been completed, and the training overhead is W ⁇ Q + H. Since the antenna array of the base station is usually larger than the number of antennas of the user end, correspondingly, the size of the horizontal subcodebook and the vertical subcodebook obtained by decoupling the analog codebook of the base station is also larger than that of the analog codebook of the user equipment. size. In this case, the beamforming overhead can be reduced by using the beamforming training mechanism shown in FIG.
- Figure 12b shows a schematic diagram of steps 1201 (flow 1) and 1204 (flow 2) in Figure 12a. That is, the process 1 indicates that the base station uses the vertical omnidirectional beam for horizontal beam scanning, and the user equipment performs the reception beam scanning; the process 2 indicates that the base station uses the optimal horizontal beam for vertical beam scanning, and the user equipment utilizes the optimal receiving beam. Receive.
- Flow 1 is shown prior to Flow 2 in Figures 12a and 12b, those skilled in the art will recognize that Flow 2 can also be performed prior to Flow 1.
- Figure 13a shows a flow diagram of beamforming training in accordance with one embodiment of the present invention in which the user's receive beam scanning is performed simultaneously in the second direction beamforming training of the base station.
- the first direction is the horizontal direction and the second direction is the vertical direction.
- the base station uses a horizontal omnidirectional beam and scans the weight vector in the vertical direction subcodebook of the base station and the weight vector in the user's analog codebook to repeatedly transmit the downlink training sequence.
- the number of transmissions of the training sequence may depend on the vertical direction subcodebook of the base station and the size of the analog codebook of the user equipment. For example, if the vertical direction subcodebook of the base station includes H weight vectors (ie, the horizontal direction subcodebook size of the base station is H), the analog codebook of the user equipment includes Q weight vectors (ie, the analog codebook of the user equipment). The size is Q), and the number of times the beamforming training sequence needs to be transmitted is equal to H ⁇ Q.
- the user estimates an equivalent channel based on the received training sequence and calculates a combination of optimal weight vectors. That is to say, according to the training sequence, the user can calculate which combination of each weight vector in the vertical direction subcodebook of the base station and each weight vector in the analog codebook of the user equipment can achieve The best channel quality. Through this calculation, the user can obtain the optimal vertical direction weight vector of the base station and the optimal reception weight vector of the user. In subsequent transmissions, the base station and the user equipment will transmit using the selected pair of weight vectors. It can be expressed as:
- f h omni is a horizontal omnidirectional beam
- w opt is the user's optimal receiving weight vector
- f v, opt is the optimal vertical direction weight vector of the base station.
- the optimal vertical direction weight vector determined by the user in step 1302 is sent to the base station as feedback of the channel estimation result.
- the base station scans the base station using the optimal vertical direction weight vector determined in step 1302.
- the weight vector in the horizontal direction subcodebook repeatedly transmits the downlink training sequence, and the user determines to use the optimal weight vector in step 1302 for reception.
- the number of transmissions of the training sequence may depend on the size of the horizontal direction subcodebook of the base station. For example, if the horizontal direction subcodebook of the base station includes W weight vectors (ie, the horizontal direction subcodebook size of the base station is W), the number of times the beamforming training sequence needs to be transmitted is equal to W.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal horizontal direction weight vector for the base station. That is to say, according to the training sequence, the user can calculate which horizontal direction weight vector in each horizontal direction weight vector in the horizontal direction subcodebook of the base station can achieve the best channel quality. It can be expressed as:
- w opt is the optimal receiving weight vector of the user trained in step 1302
- f v,opt is the optimal vertical direction weight vector of the base station trained in step 1302
- f h,opt is the optimal horizontal direction weight of the base station Vector.
- the user transmits the optimal horizontal direction weight vector of the base station determined in step 1305 to the base station as feedback of the channel estimation result.
- the base station obtains the optimal weight vector using the Kroneico product synthesis based on the optimal vertical direction reception vector determined in step 1302 and the optimal horizontal direction reception weight vector determined in step 1305, for use in Subsequent transmission of the user equipment.
- the downlink beamforming training between the base station and the user equipment has been completed, and the training overhead is H ⁇ Q+W.
- the antenna array of the base station is usually larger than the number of antennas of the user equipment. Accordingly, the size of the horizontal subcodebook and the vertical subcodebook obtained by splitting the analog codebook of the base station is also larger than the size of the analog codebook of the user equipment. In this case, the beamforming overhead can be reduced by using the beamforming training mechanism shown in FIG.
- This embodiment uses an exhaustive search mechanism in steps 1202 and 1302 described above to determine the optimal horizontal direction weight vector for the base station and the optimal receive weight vector for the user.
- embodiments of the present application are not limited to this embodiment, and those skilled in the art may recognize that the beam training process of step 1302 may also be performed using a multiple feedback search mechanism or a single feedback search mechanism in the prior art.
- the beamforming training process shown in FIG. 13 can be obtained by changing the horizontal direction in FIG. 12 to the vertical direction and the vertical direction to the horizontal direction, and other configuration parameters can be kept substantially the same.
- Figure 13b shows a schematic diagram of steps 1301 (flow 1) and 1304 (flow 2) in Figure 13a. That is, the process 1 indicates that the base station uses the horizontal omnidirectional beam for vertical beam scanning, and the user equipment performs the receiving beam scanning; the process 2 indicates that the base station uses the optimal vertical beam for horizontal beam scanning, and the user equipment utilizes the optimal receiving beam. Receive.
- Flow 1 is shown before Flow 2 in Figures 13a and 13b, Those skilled in the art will recognize that Flow 2 can also be performed prior to Flow 1.
- Figures 12-13 are merely an example and is not intended to be limiting. It should be noted that some implementations in the processes described with respect to Figures 12-13, such as a particular set of first sub-configuration parameters, a particular set of second sub-configuration parameters, and a particular set of first configuration parameters may be determined as described above Alternate implementation is done in that way.
- the antenna of the user equipment is a two-dimensional planar array antenna, but simply considers the analog codebook of the user equipment as a whole.
- the receiving beam scan of the user equipment may be split into a third direction beam scan and a fourth direction beam scan perpendicular to the third direction.
- the analog codebook of the user equipment can also be expressed in the form of the Kroneico product of the third direction subcodebook and the fourth direction subcodebook.
- the third direction and the fourth direction may be relative to a plane of the antenna array of the receiving device.
- the third direction beam scan and the fourth direction beam scan can be variously combined with the first direction beam scan and the second direction beam scan of the base station shown in FIGS. 9-13, for example, It may be performed separately from the first direction beam scan and the second direction beam scan, or may be performed simultaneously with any of the first direction beam scan and the second direction beam scan.
- the beam scanning of the first direction, the second direction, the third direction, and the fourth direction is performed separately to reduce the training overhead as much as possible. This will be described below in FIG.
- Figure 14a shows a flow diagram of beamforming training in accordance with one embodiment of the present invention in which the receive beam scanning of the user equipment is split into a vertical direction receive beam scan and a horizontal direction receive beam scan separately.
- the base station repeatedly transmits the downlink training sequence by using the omnidirectional beam, and the user equipment uses the omnidirectional horizontal beam to scan the weight vector in the vertical subcodebook of the user.
- the user's vertical direction subcodebook and the user's horizontal direction subcodebook may be pre-stored in the memory of the user equipment, or may be split by the user equipment based on the analog codebook pre-stored in the memory of the user equipment, or may be Determined directly by the user equipment based on device parameters (eg, antenna array size) and/or communication protocol conventions.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal vertical direction weight vector for the user equipment.
- the optimal vertical direction weight vector may be a vertical direction weight vector in the vertical direction subcodebook of the user equipment that makes the channel quality the best.
- step 1403 the base station repeatedly transmits the downlink training sequence by using the omnidirectional beam, and the user equipment scans the weight vector in the horizontal subcodebook of the user by using the optimal vertical direction weight vector determined in step 1402.
- the user estimates an equivalent channel based on the received training sequence and calculates an optimal horizontal direction weight vector for the user equipment.
- the optimal horizontal direction weight vector may be a horizontal direction subcodebook of the user equipment A horizontal direction weight vector with the best channel quality.
- the user obtains the optimal received weight vector using the Kroneico product synthesis based on the optimal vertical direction weight vector and the optimal horizontal direction weight vector determined at steps 1402 and 1404, respectively, for subsequent communication with the base station.
- Steps 1406 to 1412 are completely identical to steps 903 to 909 in FIG. 9, and are not described herein.
- Figure 14b shows a schematic diagram of steps 1401 (flow 1), 1403 (flow 2), 1406 (flow 3) and 1408 (flow 4) of Figure 14a. That is, the process 1 indicates that the base station uses the omnidirectional beam transmission, the user equipment uses the horizontal omnidirectional beam for the vertical beam scanning, and the process 2 indicates that the base station uses the omnidirectional beam transmission, and the user equipment uses the optimal vertical beam for the horizontal beam. Scanning; Flowchart 3 indicates that the base station uses a horizontal omnidirectional beam for vertical beam scanning, and the user equipment uses a fixed optimal receiving beam; and Flow 4 indicates that the base station uses the optimal vertical beam for horizontal beam scanning, and the user equipment uses a fixed Optimal receive beam.
- the above embodiment illustrates the case where the user's vertical beam scanning and horizontal beam scanning are completed before the vertical beam scanning and horizontal beam scanning of the base station.
- the specific embodiments of the present application are not limited to the above embodiments. It should be understood by those skilled in the art that the four beam scanning processes may be performed separately in any order, or one of the two beam scanning processes on the user side may be combined with one of the two beam scanning processes on the base station side.
- beam training may employ a periodic or aperiodic scheme.
- the base station and the user perform beamforming training at a certain time interval.
- the period of the user's receive beam training, the horizontal direction beam training of the base station, and the vertical beam training of the base station may be different.
- Flow 1, Flow 2, and Flow 3 appear in different cycles, with the beams not participating in the training maintaining the results of the last training.
- the time interval of the beam training in the vertical direction of the base station may be longer than the horizontal beam training of the base station.
- the base station observes the motion laws of each user through the historical beam training process or the positioning information, and accordingly sets an appropriate training period for each user, for example, a user who moves little in the vertical direction and has a small displacement.
- Longer vertical beam training period otherwise set the length of the beam training in the horizontal direction to ensure the accuracy of the training results.
- the beam training period can be lengthened in a specific direction of splitting, and the training overhead is further reduced compared to the existing beam training scheme. For example, compared with the feedback of a single feedback mechanism in two T cycles, the number of weight vector combinations that need to be detected by the single feedback mechanism is 2*(P+Q), where P and Q are base station and client code respectively.
- this The disclosure also supports shortening the beam training period in a particular direction, such as the horizontal direction, which is split, which has a similar or limited increase in training overhead compared to existing beam training schemes, but can significantly improve beam training accuracy.
- the user initiates a beamforming training request, and the base station performs beamforming training after processing the user request.
- the base station actively initiates beamforming training requirements and configures the user to perform beamforming training.
- the request for receive beam training of the user, horizontal beam training of the base station, and vertical direction beam training of the base station may also be initiated separately or periodically.
- the case of individual beamforming training may occur in certain special scenarios, such as when the user moves in a single direction, such as when the user is traveling in an elevator, moving in a vertical direction, then a request to separately train the vertical direction beam may be initiated.
- the first direction beamforming performed by the first communication device uses all of the first direction subcodebooks, and/or is used in the second direction beamforming. All second direction subcodebooks.
- the first direction beamforming and the second direction beamforming may use a portion of the first direction subcodebook and the second direction subcodebook, respectively.
- Beamforming training is performed by a partial horizontal direction codebook of such a horizontal direction range and/or a partial vertical direction codebook corresponding to such a vertical direction range.
- the plurality of sets of first sub-configuration parameters and the plurality of sets of second sub-configuration parameters are each a sub-configuration parameter within a predetermined range, wherein the predetermined range is at least a part of a range of all available sub-configuration parameters .
- the omnidirectional beam, the omnidirectional horizontal beam, and the omnidirectional vertical beam described above may also be replaced with other beams.
- This situation may occur but is not limited to the approximate location of the known user of the base station, using a wide beam instead of an omnidirectional beam for training.
- the wide beam here can be referred to as the gain of the beam is concentrated over a wide range of all possible values of the horizontal arrival angle and the vertical angle of arrival.
- the base station may transmit a wide beam in a corresponding direction to provide a certain beamforming, for example, according to a user's rough orientation (eg, obtained by existing direction of arrival angle estimation, LBS, etc., or GPS information). Gain to assist the user in receiving beam scans.
- the beamforming training mechanism of the present application can also be extended to a multi-user millimeter wave system.
- each radio link serves one user, and beamforming training between the radio link and the corresponding user can utilize FIGS. 9a, 10a, 11, 12a, 13a, and 14a.
- the process described in the process proceeds.
- the training sequences transmitted by different RF links should be orthogonal to each other so that multiple users can distinguish signals for themselves. Taking step 901 of FIG.
- the base station side adopts a sub-connection hybrid precoding architecture, is equipped with K radio links, and serves K users simultaneously, and H i,j represents the i-th radio link and the j-th user.
- the channel matrix, ⁇ 1 , ⁇ 2 , ..., ⁇ K ⁇ represents the orthogonal sequence used by the K radio links.
- y k represents the received signal of the kth user
- n k represents the noise of the kth user
- f omni indicates that the base station uses omnidirectional beam transmission
- w k represents the reception weight vector of the kth user.
- step 902 the kth user can obtain an estimate of the channel quality using a least squares algorithm:
- the kth user multiplies the receive channel by the transpose of the training sequence for the kth radio link used by the kth user for channel estimation.
- the k-th user beam training criterion can be expressed as:
- FIG. 15 is a flow chart showing the extension of the beamforming training flow shown in Figure 9a to a multi-user millimeter wave system in accordance with one embodiment of the present invention.
- Steps 1501 to 1509 are basically the same as steps 901 to 909 in FIG. 9a.
- the base station has multiple radio frequency links for multiple users, and each radio frequency link transmits training sequences orthogonal to each other.
- the user equipment After receiving the signal sent by the base station, the user equipment processes the received signal based on the corresponding training sequence before performing channel estimation.
- the base station sends the training sequence to multiple user equipments, it can be simultaneously transmitted through each radio frequency link.
- the user equipment feeds back an index of the optimal weight vector on its own dedicated physical uplink control channel.
- the user equipment feeds back at the MAC layer or higher, for example in the form of a bitmap, each bit representing a weight vector, 1 indicating that the corresponding bit indicates the optimal weight vector, and the others are represented by 0.
- the present invention only needs to use a small number of bits to feed back the optimal weight vector in the horizontal and vertical directions at a time, and can avoid the modification of the existing signaling structure in some scenarios. It also saves limited signaling resources.
- the beamforming mechanism proposed by the present invention can also be used in conjunction with a channel state estimation mechanism.
- the base station may obtain step 1509 using step 1509.
- the optimal transmission weight vector transmits a reference signal such as a Channel State Information Reference Signal (CSI-RS) to estimate channel state information.
- CSI-RS Channel State Information Reference Signal
- each user estimates channel state information based on the received reference signal.
- Each user feeds back channel state information such as a Precoding Matrix Indicator (PMI), a Channel Quality Indicator (CQI), and the like to the base station.
- PMI Precoding Matrix Indicator
- CQI Channel Quality Indicator
- the base station performs digital precoding using channel state information fed back by each user to multiplex transmission resources while controlling interference between users or determining a modulation and coding scheme or the like for user scheduling.
- the base station uses an analog-digital hybrid precoding architecture to simultaneously serve K users, and the base station side is equipped with K RF links.
- the UE uses an ULA antenna array. Both the base station and the UE use the classical DFT beamforming codebook design, and the codebook is determined by the following codebook matrix.
- N a represents the number of antennas
- N c represents the codebook size
- the codebook size is equal to the number of antennas.
- the overhead of beamforming training is MN OFDM symbols.
- the beamforming training overhead of the single feedback search mechanism is M+N OFDM symbols.
- the training overhead can be reduced. For example, using the beam assignment of Figure 9.
- the overhead of the shape training mechanism is W+H+N OFDM symbols, and the overhead of the beamforming training mechanism of FIG. 12 and FIG. 13 is H+W ⁇ N or W+H ⁇ N OFDM symbols, respectively. The details are shown in the table below.
- the average user reachable rate is simulated below for consideration of five options: (1) exhaustive search mechanism; (2) single feedback search mechanism; (3) The mechanism shown in Figure 9; (4) the mechanism shown in Figure 12; (5) the mechanism shown in Figure 13.
- Figure 16 shows the user reachability simulation of each beam training mechanism in a single-user scenario. It can be seen that the performance loss of the mechanism shown in Figure 9 is small (about 1 dB) compared to the traditional single feedback mechanism. However, the training overhead is The 68 time slots are reduced to 20 time slots, which is reduced by about 70%. In addition, the mechanism shown in Figure 12 and the mechanism shown in Figure 13 are close to a single feedback, but the training overhead is also reduced by about 40%. It is proved that the proposed beamforming training mechanism can greatly reduce the training overhead while achieving good performance.
- Figure 17 shows the average user reachable rate simulation of each beam training mechanism in a multi-user scenario. Similar to the single-user scenario, it can be seen that the proposed beamforming training mechanism can greatly reduce the training overhead and achieve good performance.
- a base station can be implemented as any type of evolved Node B (eNB), such as a macro eNB and a small eNB.
- the small eNB may be an eNB covering a cell smaller than the macro cell, such as a pico eNB, a micro eNB, and a home (femto) eNB.
- the base station can be implemented as any other type of base station, such as a NodeB and a base transceiver station (BTS).
- BTS base transceiver station
- the base station can include: a body configured to control wireless communication (also referred to as a base station device, such as the electronic devices 700 and 710 described herein); and one or more remote wireless headends disposed at a different location than the subject (RRH).
- a body configured to control wireless communication also referred to as a base station device, such as the electronic devices 700 and 710 described herein
- RRH remote wireless headends disposed at a different location than the subject
- various types of terminals which will be described below, can operate as a base station by performing base station functions temporarily or semi-persistently.
- the terminal device may be implemented as a mobile terminal (such as a smart phone, a tablet personal computer (PC), a notebook PC, a portable game terminal, a portable/encrypted dog type mobile router, and a digital camera device) or an in-vehicle terminal (such as a car navigation device). ).
- the terminal device can also be implemented as a terminal (also referred to as a machine type communication (MTC) terminal) that performs machine-to-machine (M2M) communication.
- the terminal device may be a wireless communication module (such as an integrated circuit module including a single wafer, such as the electronic devices 700 and 710 described in this application) installed on each of the above terminals.
- Fig. 18 shows an example of a hardware configuration of an electronic device according to the present invention.
- the central processing unit (CPU) 2301 functions as a data processing unit that performs various types of processing based on programs stored on a read only memory (ROM) 1802 or a storage unit 1808. For example, the CPU 1801 performs processing based on the aforementioned sequence.
- a random access memory (RAM) 1803 stores programs, data, and the like executed by the CPU 1801.
- the CPU 1801, the ROM 1802, and the RAM 1803 are connected to each other via a bus 1804.
- the CPU 1801 is connected to the input and output interface 1805 via a bus 1804, and an input unit 1806 composed of various switches, a keyboard, a mouse, a microphone, and the like, and an output unit 1807 composed of a display, a speaker, and the like are connected to the input and output interface 1805.
- the CPU 1801 executes various types of processing in response to an instruction input from the input unit 1806, and outputs the processing result to the output unit 1807.
- the storage unit 1808 connected to the input and output interface 1805 is constituted by, for example, a hard disk, and stores thereon programs and various types of data executed by the CPU 1801.
- the communication unit 1809 communicates with an external device via a network such as the Internet or a local area network.
- the drive 1810 connected to the input and output interface 1805 drives a removable medium 1811 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory (for example, a memory card), and acquires each of the contents such as content and key information recorded thereon.
- a removable medium 1811 such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory (for example, a memory card)
- Class data For example, by using the acquired content and key data, the CPU 1801 performs processing such as beamforming training for wireless communication based on the reproduction program.
- the methods and systems of the present invention may be implemented in a number of ways.
- the methods and systems of the present invention can be implemented in software, hardware, firmware, or any combination of software, hardware, and firmware.
- the above-described sequence of steps for the method is for illustrative purposes only, and the steps of the method of the present invention are not limited to the order specifically described above unless otherwise specifically stated.
- the invention may also be embodied as a program recorded in a recording medium, the program comprising machine readable instructions for implementing the method according to the invention.
- the invention also covers a recording medium storing a program for performing the method according to the invention.
- the methods and systems of the present invention may be implemented in a number of ways.
- the methods and systems of the present invention can be implemented in software, hardware, firmware, or any combination of software, hardware, and firmware.
- the above-described sequence of steps for the method is for illustrative purposes only, and the steps of the method of the present invention are not limited to the order specifically described above unless otherwise specifically stated.
- the invention may also be embodied as a program recorded in a recording medium, the program comprising machine readable instructions for implementing the method according to the invention.
- the invention also covers a recording medium storing a program for performing the method according to the invention.
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Abstract
本发明公开了一种无线通信方法和无线通信装置。一种用于无线通信系统的布置有多个天线的第一通信装置的电子设备包括处理电路,被配置为:基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
Description
本发明涉及一种无线通信方法和无线通信装置,特别涉及一种用于大规模多输入多输出通信系统的无线通信方法和无线通信装置。
近年来,大规模多输入多输出(Massive Multi-Input Multi-Output,MIMO)技术和毫米波(Millimeter Wave)技术被认为是未来5G关键技术的一部分,引起了学术界和工业界的广泛关注。毫米波频段具有大量可用频谱资源,能够满足移动通信日益增长的业务流量需求。此外,由于毫米波的波长较短,根据天线理论,毫米波系统的天线尺寸也较小,使得能够在小范围空间中放置几百甚至上千根天线,更有利于大规模天线技术在现实系统中的应用。此外,大规模天线所提供的波束赋形技术能有效弥补毫米波信道路径衰落过大的缺点,为毫米波技术应用于移动通信提供了可能。
全维度多输入多输出技术(Full Dimension MIMO,FD-MIMO)也是工业界关注的热点之一。通过部署二维平面天线阵列,FD-MIMO能够同时提供水平方向和垂直方向的自由度。与传统线性天线阵列相比,FD-MIMO能够在有限空间内部署更多天线,进而提升空间分集和复用的性能。然而,大规模MIMO尤其是FD-MIMO场景下如何在通信双方高效地进行波束赋形传输已成为产业界重点关注的研究方向。
发明内容
本发明的发明人发现,当基站端配备大规模天线、尤其是多维度天线阵列时,现有的波束赋形训练机制的开销仍较大。进一步地,在用户设备和基站都配置有多个天线的情况下,随着天线数目和用户数目的增大,用于波束赋形训练的开销越来越大。而且,当存在多用户的情况时,需要针对每一个用户都确定对应的波束赋形参数以进行传输,对于此,用于波束赋形训练的开销的问题更加突出。
但是,另外,目前并没有可行的方案能够解决这些问题。
因此,本发明的一个目的在于提供改进的用于波束赋形的技术,尤其是用于无线通信的技术方案。
鉴于此,本申请提出了一种改进的波束赋形训练技术,其的基本思路在于通过将
待确定的配置参数(例如,关于天线相应的移相器的配置参数,诸如权重矢量)分解为若干子配置参数,分别通过对应的训练来确定子配置参数,由此可以根据分别训练得到的最优子配置参数来进行配置。在一种实现中,对于二维天线阵列的情况,可以分别进行水平方向波束训练和垂直方向波束训练以分别获得最优的水平方向子配置参数和最优的垂直方向子配置参数,并且基于所分别获得的最优的水平和垂直方向子配置参数来配置天线对应的移相器,例如基于这两个方向的子配置参数的克罗内科积来配置移相器。
根据本发明的一个方面,提供了一种用于无线通信系统的第一通信装置的电子设备,其中,第一通信装置布置有多个天线,所述电子设备包括:处理电路,被配置为:基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
根据本发明的另一方面,提供了一种用于无线通信系统的第二通信装置的电子设备,其中,所述电子设备包括处理电路,被配置为:获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
根据本发明的还另一方面,提供了一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括:基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置
第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
根据又另一方面,提供了一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
根据本发明的实施例,在无线通信中用于波束赋形训练的开销可被减小。
根据本申请的实施例,还可以在保持波束赋形训练开销较低的同时,进一步减小信令开销。
通过以下参照附图对本发明的示例性实施例的详细描述,本发明的其它特征及其优点将会变得清楚。
构成说明书的一部分的附图描述了本发明的实施例,并且连同说明书一起用于解释本发明的原理。
参照附图,根据下面的详细描述,可以更加清楚地理解本发明,其中:
图1是示出一种现有技术的基站的结构的示图。
图2是示出一种配置有单根天线的用户端的示图。
图3是示出一种配置有多根天线的用户端的示图。
图4a和图4b分别示出了单用户系统中的基站端和用户端的配置的示图。
图5a和图5b分别示出了模数混合预编码架构下的基站端和用户端的配置的示图。
图6a和图6b分别示出了全连接移相网络和子连接移相网络的示意图。
图7a示出了根据本发明一个实施例的用于无线通信系统中的一个通信装置的电子设备的示意图。
图7b示出了根据本发明一个实施例的用于无线通信系统中的另一个通信装置的电子设备的示意图。
图8示出了根据本发明的一个实施例在基站中采用图7的电子设备进行波束赋形训练的流程图。
图9a示出了根据本发明的一个实施例的波束赋形训练的流程图。
图9b示出了根据本发明的一个实施例的波束赋形训练的示意图。
图10a示出了根据本发明的一个实施例的波束赋形训练的流程图。
图10b示出了根据本发明的一个实施例的波束赋形训练的示意图。
图11示出了根据本申请的一个实施例的波束赋形训练的流程图。
图12a示出了根据本发明的另一个实施例的波束赋形训练的流程图。
图12b示出了根据本发明的另一个实施例的波束赋形训练的示意图。
图13a示出了根据本发明的另一个实施例的波束赋形训练的流程图。
图13b示出了根据本发明的另一个实施例的波束赋形训练的示意图。
图14a示出了根据本发明的另一个实施例的波束赋形训练的流程图。
图14b示出了根据本发明的另一个实施例的波束赋形训练的示意图。
图15示出了多用户毫米波系统中的波束赋形训练的流程图。
图16示出了根据本申请的一个实施例的用户平均可达速率与信噪比的曲线图。
图17示出了根据本申请的一个实施例的用户平均可达速率与信噪比的曲线图。
图18示出了一种根据本发明的电子设备的硬件配置的示例。
现在将参照附图来详细描述本发明的各种示例性实施例。应注意到:除非另外具体说明,否则在这些实施例中阐述的部件和步骤的相对布置、数字表达式和数值不限制本发明的范围。
同时,应当明白,为了便于描述,附图中所示出的各个部分的尺寸并不是按照实际的比例关系绘制的。
以下对至少一个示例性实施例的描述实际上仅仅是说明性的,决不作为对本发明及其应用或使用的任何限制。
对于相关领域普通技术人员已知的技术、方法和设备可能不作详细讨论,但在适当情况下,所述技术、方法和设备应当被视为授权说明书的一部分。
在这里示出和讨论的所有示例中,任何具体值应被解释为仅仅是示例性的,而不是作为限制。因此,示例性实施例的其它示例可以具有不同的值。
应注意到:相似的标号和字母在下面的附图中表示类似项,因此,一旦某一项在一个附图中被定义,则在随后的附图中不需要对其进行进一步讨论。
传统的无线通信系统中,通常,在发射端(例如,基站端)和接收端(例如,用户设备),每根天线连接一个射频链路,以便进行发送和接收。一般概念上而言,在操作中,在发射端,待发射的数据流首先进行基带处理,然后经由射频链路被转换成射频信号以通过对应的天线被发射,而接收端对应的射频链路将接收的射频信号处理为基带信号,然后进一步进行基带处理以获得希望的数据流。
通常,在基带数据处理中,为了便于数据流经由射频链路和对应的天线进行发送,主要采用数字预编码架构,其中每根天线连接一个射频链路,在各个射频链路上发送信号的幅值均可调,以降低在相同的传输资源上承载的多路数据信号彼此间的干扰。这样的在数据经由射频链路和天线被发送之前的处理可被称为发射端的数据的基带数字处理。
例如,图1示意性地示出了一种现有技术的基站的概念性结构。如图1所示,在数字预编码架构下,基站端配备有M根天线(M为整数且M≥1),每根天线布置有对应的射频链路。数字预编码器在控制器的控制下获取K路数据流(K为整数且K≥1),对这K路数据流进行数字预编码(例如,使K路数据流经大小为M×K的数字预编码矩阵B)。编码后的数据经由射频链路和天线被发送给一个或多个用户。
相应地,用户端可以有多种配置形式,以便在通过射频链路接收到编码的数据之后进行对应的基带数字处理以便获得希望的数据流。
图2示出了一种配置有单根天线的用户端。如图2所示,用户端设置有单根天线和对应的单个射频链路。由于该用户端只有一根天线,因此只能接收单个数据流。也就是说,从基站端M个天线发送的K路数据流中,通过相应的数字处理,使得只有一路数据流能够被用户端接收。
图3示出了一种配置有多个天线的用户端。如图3所示,该用户端配置有N根天线(N为整数且N>1)。每根天线通过对应的射频链路把接收到的数据传输给数字预编码器。数字预编码器在控制器的控制下,使用例如大小为Ku×N的数字预编码矩阵W
(Ku为整数且Ku≧1)对接收到的数据进行数字预编码,从而得到单路(Ku=1时)或多路数据(Ku>1时)。
对于数字预编码器中使用的数字预编码矩阵,通常有基于码本(codebook based)和不基于码本(non-codebook based)两种设计方式。在基于码本的设计方案中,数字预编码矩阵必须从预先设定的码本中选取。而在不基于码本的设计方案中,则没有这样的约束。基站端和用户端可以根据信道状态信息(Channel State Information,CSI)设计预编码矩阵。
上述的数字预编码处理可被认为属于无线通信中的基带数字处理部分。
进一步地,在无线通信系统、尤其是毫米波通信系统中,在通过射频电路和对应的天线发射经预先数字处理的数据时,由于射频链路的实现复杂度和成本比较高,因此通常采用每条射频链路连接多个移相器及天线而利用少至一条射频链路形成具有指向性的波束,从而实现模拟波束赋形方案。模拟波束赋形训练是指优化基站和用户设备的配置信息(例如,涉及基站和用户设备的移相器的配置值,也被称为用于移相器的权重矢量)的过程,其主要作用是提高用户接收信噪比。以下行链路为例,基站通过配置与其多个天线连接的多个移相器的值来形成具有指向性的发送波束,用户设备通过配置与其多个天线连接的多个移相器的值来形成具有指向性的接收波束,基站的发送波束与用户设备的接收波束构成了下行链路的一组波束对。下行波束赋形训练的过程即找到由最优的基站发送波束和最优的用户设备接收波束构成的一组最优的波束对的过程。类似地,在上行链路中,基站的接收波束与用户设备的发送波束也构成一组波束对。
毫米波通信系统有多种工作模式,例如点对点模式、单用户模式、多用户模式等。点对点模式可用于基站(BS)间回传,单用户模式和多用户模式可用于基站与一个或多个用户设备(UE)间通信。在实现架构上,可以包括模拟波束赋形、全连接模数混合预编码、子连接模数混合预编码等。但无论采用哪种架构,受器件约束的限制,基站和用户设备的配置信息(例如,涉及基站和用户设备的移相器的配置值)只能从预先定义的模拟码本中选择,通常这样的配置信息可被称为权重矢量,其通常指的是移相器的配置值(例如,相位值)。
这样的处理主要是在无线通信系统的发射端和接收端的射频部分进行的,可被认为是射频模拟处理。
以下将通过附图示例性地描述波束赋形技术的概念。
图4a和图4b分别示出了单用户系统中的基站端和用户端的配置。如图4a和图4b所示,在用户端和基站端中,每个射频链路均连接有一组移相器,各个移相器再分别连接到各自对应的天线。一组移相器的值(例如相位值)可由一组配置参数指示,该组配置参数例如为DFT向量,也被称为权重矢量或波束向量。本文中,我们把基站端的权重矢量表示为f,把用户端的权重矢量表示为w。由于移相器仅调整信号的相位而不改变幅度,因此权重矢量中各个元素的幅值均为1。在这种结构的毫米波通信系统中,由于射频链路的数量有限,基站端和用户端都无法直接估计信道状态信息。所以通常的模拟波束赋形方案采用基于模拟Tx/Rx码本的方法。码本是一组权重矢量的集合。设基站端码本为F,码本大小为P(包含P个权重矢量),用户端码本为W,码本大小为Q(包含Q个权重矢量),则基站端的权重矢量必须从基站端码本F中选取,用户端的权重矢量必须从用户端码本W中选取。
在基站端和用户端进行毫米波通信时,具体采用码本中的哪一个权重矢量要事先通过波束训练来确定。波束训练例如可以采用最大化信噪比准则来确定用于形成最佳波束的权重矢量,可以表示为:
{wopt,fopt}=argmax|wTHf|其中w∈W,f∈F
其中,H∈N×M表示基站端和用户端之间的下行信道,W是关于用户端的权重矢量的候选集合(码本),F是关于基站端的权重矢量的候选集合(码本),而wopt,fopt分别是所确定的关于用户端和基站端的最优的权重矢量。
由于毫米波信道路径衰减大的特性,毫米波多径信道的散射体数量较少,通常可以将毫米波信道H建模为
其中,N和M分别表示用户端和基站配备的天线数量,Ncl为散射体数量,Nray为每个散射体包含的子径个数,αi,l表示相应散射路径的信道系数,aUE和aBS分别表示用户端和基站的天线响应向量,θ和φ分别为水平方向和垂直方向到达角。
对于线性天线阵列(Uniform Linear Array,ULA),天线响应向量与垂直到达角φ无关,可以表示为
其中λ为波长,d为天线间距,N为天线数。
在多用户场景下,毫米波无线通信系统还可以采用模数混合预编码架构。图5a和图5b分别示出了模数混合预编码架构下的基站端和用户端的配置。
如图5a所示,采用模数混合预编码架构的基站端具有基带数字预编码器和模拟移相网络。在控制器的控制下,基带数字预编码器获取K路数据流作为输入,基带数字预编码器对这K路数据进行数字预编码,从而消除不同数据流之间的干扰。然后,K个射频链路对经过数字预编码器预编码的数据流进行上变频、放大、滤波等处理,从而变成射频信号。通常,K个射频链路中,每个射频链路对应于一个用户端。
K个射频链路连接到模拟移相网络。移相网络中各个移相器的取值构成了模拟波束赋形矩阵F。在矩阵F中,第k列表示第k个射频链路连接的一组移相器的值,表示为权重矢量fk,权重矢量fk必须从基站端的码本f中选取。
对于移相网络,可以有各种不同的实现方式。图6a和图6b分别示出了全连接移相网络和子连接移相网络的示意图。
如图6a所示,在全连接移相网络中,每个射频链路连接到一组M个移相器,从而在全连接移相网络中有K组移相器,移相器的总数目为K×M个。每组移相器中对应移相器输出的信号(K个信号)经过加法器相加后被提供给对应的天线单元。在全连接移相网络中,每个射频链路可以经模拟移相器连接到所有天线。
如图6b所示,在子连接移相网络中,每个射频链路的输出端连接到P个移相器(P为整数且P≥1),每个移相器连接到一个天线单元。也就是说,在具有K个射频链路的情况下,天线单元的数目M=K×P。在子连接移相网络中,每个射频链路经模拟移相器连接到部分天线。通常天线是平均分配给K个射频链路的。
图5b示出了采用混合预编码架构的用户端的配置。如图5b所示,用户端配置有N个天线,每个天线接收到的信号经过对应的移相器后输入到射频链路。各个移相器的取值构成了用户端权重矢量wk,可以从用户端码本W中选择用户端权重矢量wk。射频链路对输入的信号进行滤波、放大、下变频后得到数字接收信号。
在该示例中,用户端具有多个射频链路。根据实际情况,也可以在用户端采用一个射频链路的设计。
在混合预编码架构下,波束训练就是从预先规定的码本中确定基站端和用户端的权重矢量的过程。以下行传输为例,最大化信噪比准则可以表示为:
{wk,opt,fk,opt}=argmax||wTHkf||其中w∈W,f∈F
其中{wk,opt,fk,opt}表示第k个用户最优的下行权重矢量,Hk为基站和第k个用户间的下行信道矩阵。
传统的波束赋形训练机制主要包括物理信道估计、穷尽搜索、多次反馈和单次反馈。
1、物理信道估计。物理信道估计机制通过导频直接估计下行物理信道用户端根据估计的物理信道计算最优的基站端权重矢量和用户端权重矢量,并将基站端权重矢量或权重矢量的索引反馈给基站。但在毫米波系统中,基站和用户均配备大量天线,信道估计的复杂度极高,并且信道估计过程中导频未经波束赋形,导致接收信噪比较低,信道估计的准确度较低。
2、穷尽搜索。穷尽搜索机制搜索基站端的权重矢量和用户端的权重矢量的所有可能的组合,用户端测量在每对发送/接收权重矢量下的信道质量,从中选择最优的一组,并将最优的基站端权重矢量或者基站端权重矢量索引反馈给基站。穷尽搜索机制可以达到最优的性能,但复杂度极高,需要搜索的权重矢量的组合个数为P×Q,其中P和Q分别为基站端和用户端码本大小。
3、多次反馈。多次反馈机制通过预先设计的多层码本,将训练过程分为多层进行,在每层中使用穷尽搜索。由于每层中备选码字数量较小,因而复杂度得到降低。多次反馈机制需要探测的权重矢量组合个数为其中Pl和Ql分别为基站端和用户端第l层码本的大小,L为码本层数。
4、单次反馈。为了进一步减小波束训练算法的复杂度,可以只选择用户端的权重矢量和基站端的权重矢量的全部组合中的一部分进行探测。例如,可以是基站端码本中的一个权重矢量与用户端码本中的全部权重矢量的组合,也可以是用户端码本中的权重矢量之一与基站端码本中的全部权重矢量的组合。例如,在一个实施例中,可以根据基站端码本中的权重矢量之一与用户端码本中的全部权重矢量的组合所得到的信道质量,选择用户端码本中的权重矢量中要与基站端码本中的全部权重矢量进行组合的权重矢量。一个具体的例子就是单次反馈机制。单次反馈机制将波束赋形训练拆分为两个流程,首先,基站按照基站端码本中的每个权重矢量发送信号(例如导频信号),用户端使用全向波束(例如,用户端预定的一个权重矢量如仅利用天线阵列中的一个天线进行接收)接收并估计与基站端码本中的每个权重矢量对应的信道质量,用户端
从中选择信道质量最优的权重矢量并将其索引反馈给基站。随后,基站固定使用用户端选择的权重矢量发送信号,用户端则从码本中选择信道质量最高的权重矢量,作为要与基站进行通信的权重矢量(即计算用户端码本中每个权重矢量与该基站端的固定的权重矢量的组合所得到的信道质量,并选择与最高的信道质量对应的组合)。相比穷尽搜索机制,单次反馈机制的复杂度大大降低。单次反馈机制需要探测的权重矢量组合个数为P+Q,其中P和Q分别为基站端和用户端码本大小。
上面以单用户场景下的下行传输为例对波束训练方法进行了说明。在上行传输过程中执行的过程基本类似,主要区别在于用户端发送信号,基站端接收信号。另外,信道质量可以通过信道估计来得到。通过信道估计,能够得到信道方向和信道质量。在信道估计结果中,可以包括指示信道质量的信息例如LTE标准中采用的CQI(Channel Quality Indicator)和对应的参数组的标识信息(最优权重矢量索引),也可以包括最佳的多个CQI和每个CQI对应的参数组的标识信息。
在多用户场景下,波束训练方法可采用上述的穷尽搜索、多次反馈搜索或单次反馈搜索机制,或其他多用户波束搜索机制。
在FD-MIMO系统中,基站和用户端的天线规模巨大,所能形成的候选波束更多,相应的基站端码本和用户端码本也很大。现有的穷尽搜索、多次反馈搜索或单次反馈搜索机制所需的波束赋形训练难以满足实际应用需求。
对于此,申请人提出了改进的波束赋形训练方案。
特别地,申请人注意到,在大规模天线的无线通信环境中,多个天线通常可以被布置为二维平面天线阵列,在此情况下,天线响应向量通常可分解为若干子向量的组合,而与此对应的,用于波束赋形的权重矢量也相应地分解为与该子向量对应的子矢量,因此在波束赋形训练中可分别进行训练,由此得到所确定的权重矢量的各子矢量,最后通过所确定的各子矢量的组合可以确定希望的权重矢量。
举例而言,在天线被布置为二维天线阵列的情况下,对于W×H的平面天线阵列(Uniform Planar Array,UPA),其中W为水平方向天线数,H为垂直方向天线数,天线响应向量可以表示为
鉴于此,当基站端配备二维平面天线阵列时,由于天线响应向量的克罗内科积结构,相对应地,模拟码本F也可由水平码本Fh和垂直码本Fv利用克罗内科积生成,即基于此,本公开利用构成巨大模拟码本的水平码本和垂直码本分别在水平域和垂直域上进行波束赋形训练,得到最优的水平方向权重矢量和垂直方向权重矢量后,再利用克罗内科积计算得到训练出的最优权重矢量。
应理解,上述的克罗内科积是作为便于实现的优选的示例被说明的,其他适当的用于码本的分解和组合的运算也是可能的,并且能够实现类似的效果。而且,本发明的一个重点是将训练拆分为两个方向,对天线的形状、码本没有强制约束,在可能的多天线被以其它的二维或者三维方式布置(例如曲面天线阵列或圆柱体状的天线阵列)的情况下,仍然可以通过拆分为两个方向训练,得到最优的第一方向和第二方向角度信息,利用特定的信号处理算法计算最终最优的波束,在使用码本的示例中,也可以构想到其它合适的用于码本的分解和组合的运算,并且仍可实现类似的效果。
例如,在天线排布为三角形的平面天线阵列的示例中,本发明所提出的波束训练算法仍然适用。在这种三角形或异型天线阵列示例中天线响应向量即使不具有克罗内科积结构,但是由于天线仍是二维或以上天线阵列,因此可以合理地设计出适当的移相器配置值(可以基于码本,也可以不基于码本)来使得三角形的天线阵列分别得出垂直方向和水平方向的波束,并且分别进行垂直方向和水平方向的波束训练来获知特定用户的方向,然后将垂直和水平方向训练结果进行特定组合(非克罗内科积形式的组合)来获得天线阵列权重矢量以配置实际传输。例如,在第一步,令基站发送水平全向,垂直有方向性的多个波束,这样通过扫描即可获知垂直方向的波束信息,或者直观来说信道的垂直到达角信息。接着,在第二步,令基站发送垂直域上对准第一步确定的方向,而水平有方向性的多个波束,这样通过扫描就知道了水平方向的波束信息,或者直观来说信道的水平到达角信息。最后,基站利用水平波束信息和垂直波束信息,通过信号处理算法就能合成出最终用于服务的波束。此外,尽管前文提及了在训练码本中选择适当的码本作为最优的方向权重矢量以配置实际传输的情况,但是应指出,本发明的基本构思仍可适用于最终确定的权重矢量是在训练码本之外的情况。
例如,在待被确定的权重矢量所对应的规定的实际码本不具有克罗内科积特性的情况下,可以采用具有克罗内科积特性的码本专用于训练,该码本是垂直和水平两部分组成的,训练结束后,将训练得到的最优权重矢量与实际码本中的码字进行比较找到最接近的以用于实际传输。
例如,如果对于待被确定的权重矢量没有规定码本的情况下,可以采用具有克罗内科积特性的码本专用于训练以得到的最优权重矢量,并且根据训练得到的最优权重矢量与次优权重矢量或其他因素进行插值等调整来作为实际使用的权重矢量。
应指出,相比现有的波束赋形训练机制,本申请的训练方法的复杂度通常能够进一步降低。例如,与单次反馈机制反馈相比,单次反馈机制需要探测的权重矢量组合个数为P+Q,其中P和Q分别为基站端和用户端码本大小。而在基站端码本可分解的情况下,P=W*H,则本申请的训练方法的复杂度最低可少至W+H+Q。
根据实施例,本申请提出了一种波束赋形训练方法和实现该方法的设备,其中通过将待确定的配置参数(例如,权重矢量)分解为若干子配置参数,分别确定子配置参数并且组合所确定的子配置参数来重构最优的配置参数,来进行波束赋形训练,这样的训练过程至少能够获得与现有的波束赋形训练相似的性能,而同时训练开销则显著降低。
以下将参照附图对本发明的实施例进行描述。
根据一个实施例,提出了一种用于无线通信系统中的第一通信装置的电子设备,其中该通信装置布置有多个天线。电子设备可包括处理电路,该处理电路可被配置为基于多组第一子配置参数分别配置第一通信装置对该无线通信系统中的第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
根据实施例,该第一通信装置可以是基站,也可以是用户设备,而作为对应,第二通信装置可以是与基站通信的用户设备,也可以是与用户设备通信的基站。
根据实施例,用于第一通信装置的一组第一配置参数是用于配置与所述多个天线一一对应的一组移相器的各移相器的相位值(也就是前述的权重矢量),而一组第一配置参数可以分解为一组第一子配置参数和一组第二子配置参数,并且可以通过该组第一子配置参数和该组第二子配置参数的组合(可以是分解的逆运算,例如,克罗内
科积)而被重构。基于这样的认知,可以分别从候选的码本中分别确定特定一组第一子配置参数和特定一组第二子配置参数,由此确定特定一组第一配置参数。
作为候选码本的多组第一子配置参数中的每一组可以是用于配置与所述多个天线一一对应的一组移相器中的多个移相器的相位值,而所述多组第二子配置参数中的每一组可以是用于配置所述一组移相器中的多个移相器的相位值。其中,上述与多组第一子配置参数对应的多个移相器和上述与多组第二子配置参数对应的多个移相器可不同。
根据实施例,多组第一子配置参数可以与多个天线的第一方向相关联的,即可被称为多个第一方向权重矢量,并且可被称为第一方向码本。该第一方向子码本中的每一组第一子配置参数可以通过配置与基站的多个天线一一对应的一组移相器的相位值,来使所产生的信号的指向性在第一方向上分布。多组第二子配置参数可以与多个天线的第二方向相关联的,即多个第二方向权重矢量,并且可被称为第二方向码本。该第一方向和第二方向可以是相对于基站的多个天线的平面的。该第二方向子码本中的每一组第二子配置参数可以通过配置与基站的多个天线一一对应的一组移相器的相位值,来使所产生的信号的指向性在第二方向上分布。通常,该第一方向可以是相对于基站的多个天线的平面的水平方向,第二方向可以是垂直于该多个天线的平面的垂直方向。在其它情况下,该第一方向可以是垂直方向,并且该第二方向是水平方向。该第一方向和第二方向还可以是其它的方向,只要保证相互正交即可。
根据实施例,基于多组第一子配置参数分别配置所述第一传输可包括基于多组第一子配置参数和预定的一组第二子配置参数来配置所述第一传输。其中,该预定的一组第二子配置参数可以是由无线通信系统预先确定的。
根据实施例,基于多组第二子配置参数分别配置所述第二传输可包括基于所述特定一组第一子配置参数和多组第二子配置参数来配置所述第二传输。
根据实施例,第一传输相关的信息可以是指示所述第一传输的通信信道质量的信息。作为示例,这样的信息可以是通过在第二通信装置处进行传输的信道估计而获得的。例如,这样的信息可以包含与每一组第一子配置参数对应的第一传输的通信信道质量估计,由此可以根据估计结果确定对应于最优通信信道质量的一组第一自配置参数作为特定一组第一子配置参数。根据实施例,所述第一传输相关的信息还可以指示所述第一传输的通信信道质量最优的一组第一子配置参数或者该一组第一子配置参数的索引。在后者的情况下,可以从预先存储或者获得的多组第一子配置参数中找到与
该索引对应的一组第一子配置参数。
这样的信息可以由与第一通信装置通信的第二通信装置获得或者由第一通信装置和第二通信装置之外的其它装置获得,而特定一组第一子配置参数可由第二通信装置或者其它装置来确定并被提供给第一通信装置,或者可以由第一通信装置的处理电路基于被供给的这样的信息来确定,或者可以由第一通信装置的其它电路基于被供给的这样的信息来确定并提供给该处理电路。
所述第二传输相关的信息可以是指示所述第二传输的通信信道质量的信息。该信息可以与第一传输相关的信息类似,并且特定一组第二子配置参数可以与特定一组第一子配置参数类似的方式被获得。因此,在此省略所述第二传输相关的信息的详细描述。
根据实施例,该特定一组第一配置参数可通过特定一组第一子配置参数和特定一组第二子配置参数的组合(例如,克罗内科积)确定。作为示例,该特定一组第一配置参数可由第一通信装置的处理电路确定,或者由第一通信装置的除处理电路之外的装置确定并且提供给处理电路,或者可由第一通信装置之外的装置(例如,第二通信装置或者其它通信装置)确定并提供给处理电路。
根据实施例,还提出了一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
这样的方法可由无线通信系统中的第一通信装置来实现,或者由无线通信系统中的第一和第二通信装置之外的其它装置来实现。
为了更加有助于理解,以下将参照图7a描述在第一通信装置为基站、第二通信装置为用户设备的情况下的本发明的技术的实现。图7a示出了该基站具有处理电路701、以及可选的权重矢量合成单元702和存储器703,这一点在附图中由虚线框指示。应
指出,这样的描述仅仅是作为示例的,而不是作为限制。
根据实施例,多组第一组子配置参数(第一方向子码本)和多组第二组子配置参数(第二方向子码本)可以预先存储于第一通信装置的存储器703中,或者从预先存储于第一通信装置的存储器中的多组第一配置参数703得出。应指出,存储器703不是第一通信装置700必需的,在某些情况下,第一方向子码本和第二方向子码本可以由第一通信装置通过一些参数(例如,天线阵列的大小)直接确定,或者,也可以从第一通信装置之外被提供。
在操作中,处理电路701可以用于配置基站的信号传输,使得基站和用户设备之间的波束赋形训练基于基站的第一方向子码本和第二方向子码本进行。
例如,在第一方向波束赋形训练(第一传输)中,基站基于第一方向子码本发送信号(例如,导频信号或者参考信号、训练信号)以与用户设备进行通信,用户设备根据基站发送的信号来进行信道估计,使得基于该估计可以确定对于通信最优(例如,通信信道质量最优)的第一方向权重矢量(即用于移相器的特定的一组第一子配置参数)。在第二方向波束赋形训练(第二传输)中,基站基于第二方向子码本发送信号(例如,导频信号或者说参考信号、训练信号)以与用户设备进行通信,用户设备根据基站发送的信号来进行信道估计,使得可以确定对于通信最优(例如,通信信道质量最优)的第二方向权重矢量(即特定的一组第二子配置参数)。
子配置参数可以由用户设备确定并作为通信相关的信息被提供给基站,或者可由除基站和用户设备之外的其它装置基于估计结果来确定并被提供给基站。或者,该估计结果可被用户设备提供给基站,从而在基站处进行子配置参数的确定。
在知晓了所确定的最优的第一方向权重矢量(即特定的一组第一子配置参数)和最优的第二方向权重矢量(即特定的一组第二子配置参数)之后,可以通过它们的特定组合得到用于基站的最优权重矢量(即特定一组第一配置参数),其用于配置一组移相器中的各个移相器的相位值。该特定组合例如可以是克罗内科积。
该最优权重矢量的确定可在第一通信装置(例如,基站)执行,例如由处理电路701执行,或者由处理电路之外的权重矢量合成单元702执行,当然权重矢量合成单元702是可选的。作为替代,该最优权重矢量可由用户设备确定或者由除用户设备之外的其它装置确定并被提供给第一通信装置。
根据实施例,提供了一种用于无线通信系统的第二通信装置的电子设备,其中,所述电子设备包括处理电路,该处理电路被配置为获取由第一通信装置基于多组第一
子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
根据实施例,所获取的传输相关的信息可以由第二通信装置通过进行传输的信道估计而得到,或者由第一通信装置和第二通信装置之外的其它装置通过进行传输的信道估计得到并提供给第二通信装置。
根据实施例,该电子设备进行的信息的获取可以多种方式执行。根据一个实施例,获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息可包括获取由第一通信装置基于多组第一子配置参数和预定的一组第二子配置参数配置的第一传输的通信信道质量的信息;其中,所述特定一组第一子配置参数是使得所述第一传输的通信信道质量最优的一组第一子配置参数。
根据实施例,获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息包括获取由第一通信装置基于所述特定一组第一子配置参数和多组第二子配置参数来配置的所述第二传输的通信信道质量的信息;其中,所述特定一组第二子配置参数是使得所述第一传输的通信信道质量最优的一组第二子配置参数。
作为示例,上述通信信道质量信息可以由第二通信装置本身获得,例如可由处理电路直接获得或者由第二通信装置中的其它部件获得并提供给处理电路,或者可由第二通信装置之外的其它装置获得并提供给第二通信装置。
以下参照图7b进行示例性描述,图7b示出了根据本发明一个实施例的用于无线通信系统中的另一个通信装置的电子设备的示意图。该另一个通信装置用于与图7a的通信装置进行通信的。例如,当图7a的电子设备700位于基站中时,图7b的另一个电子设备710是用户设备。当图7a的电子设备700位于用户设备中时,图7b的另一个电子设备710是基站。下面以图7b的电子设备位于用户设备中为例进行描述。
如图7b所示,该电子设备710可以包括存储器711、处理电路712。
存储器711可以用于如图7a中的存储器703一样存储基站的模拟码本和/或第一
方向子码本和第二方向子码本。基站的模拟码本和/或第一方向子码本和第二方向子码本可以由基站发送给电子设备710。为节省信令开销,基站也可以仅发送基站的一些设备参数(例如,天线阵列的尺寸),电子设备710可以基于该设备参数确定用于基站的模拟码本和/或第一方向子码本和第二方向子码本。同存储器703一样,该存储器711也不是电子设备710所必需的。
在操作中,处理电路712可以对于基站基于第一方向子码本发送的信号传输(第一传输)进行信道估计,并将信道估计结果的反馈发送给基站,以便于基站确定最优的第一方向权重矢量(即,特定的一组第一子配置参数)。在一些情况下,该信道估计结果的反馈可以是第一方向子码本中使得通信信道质量最优的第一方向权重矢量或者该第一方向权重矢量的索引。在另一些情况下,该信道估计结果的反馈可以仅仅是信道估计结果本身,而基站根据所接收的信道估计结果来确定对应于最优通信信道质量的第一方向权重矢量。
当然,该信道估计结果的反馈也可提供给除基站和用户设备之外的其它装置以确定第一方向权重矢量,所确定的第一方向权重矢量随后被提供给第一通信装置
处理电路712还可以根据基站基于第二方向子码本发送的信号传输(第二传输)进行信道估计,并将信道估计的结果反馈给基站,以便于基站确定最优的第二方向权重矢量(即,特定的一组第二子配置参数)。在一些情况下,该信道估计结果的反馈可以是第二方向子码本中使得通信信道质量最优的第二方向权重矢量或者该第二方向权重矢量的索引。在另一些情况下,该信道估计结果的反馈可以仅仅是信道估计结果本身,而基站根据所接收的信道估计结果来确定对应于最优通信信道质量的第二方向权重矢量。
当然,该信道估计结果的反馈也可提供给除基站和用户设备之外的其它装置以确定第二方向权重矢量,所确定的第二方向权重矢量随后被提供给第一通信装置。
此外,由第一方向权重矢量和第二方向权重矢量组合得到的最优方向权重矢量也可由用户设备确定并提供给基站,可由基站自身确定,或者可由除用户设备和基站之外的装置确定并提供给基站。
根据实施例,提供了一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以
及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
以下将参照图8来描述根据实施例的波束赋形训练的一种示例性实现,图8示出了根据本发明的一个实施例在基站中采用图7a和7b的电子设备进行波束赋形训练的流程图。
如图8所示,在步骤801,基站向用户设备指示第一方向波束赋形训练参数,例如:用于该用户设备的训练序列指示信息、第一方向波束赋形训练的开始时间和结束时间(例如,子帧序号)、训练序列的发送次数等。
在步骤802,基站基于第一方向子码本向用户发送训练序列,以进行第一方向波束赋形训练。具体来说,基站基于第一方向子码本中的每个第一方向权重矢量(每组第一子配置参数)重复发送训练序列。
在步骤803,用户设备使用处理电路712,基于训练序列来进行信道估计,并将信道估计结果的反馈发送给基站。信道估计结果的反馈例如是第一方向子码本中的使得通信信道质量最优的第一方向权重矢量(特定的一组第一子配置参数),或者是该第一方向权重矢量的索引,或者简单地是信道估计结果本身。
在步骤804,基站向用户设备指示第二方向波束赋形训练参数,例如:第二方向波束赋形训练的开始时间和结束时间(例如,子帧序号)、训练序列的发送次数等
在步骤805,基站基于第二方向子码本向用户发送训练序列,以进行第二方向波束赋形训练。具体来说,基站基于第二方向子码本中的每个第二方向权重矢量(每组第二子配置参数)重复发送训练序列。
在步骤806,用户设备使用处理电路712,基于训练序列来进行信道估计,并将信道估计结果的反馈发送给基站。信道估计结果的反馈例如是第二方向子码本中的使得通信信道质量最优的第二方向权重矢量(特定的一组第二子配置参数),或者是该第二方向权重矢量的索引,或者简单地是信道估计结果本身。
在步骤807,基站基于最优的第一方向权重矢量(特定的一组第一子配置参数)和最优的第二方向权重矢量(特定的一组第二子配置参数)通过特定组合得到最优的权重矢量(特定的一组第一配置参数)。
应理解,上文描述的基站进行第一方向波束赋形训练或者基于第一方向子码本向用户发送训练序列在实现中包括:基站基于第一方向子码本中的每个第一方向权重矢量与某个第二方向权重矢量的克罗内科积合成得到多组第一配置参数,用于设置与基站的多个天线对应的一组移相器的相位值,以进行传输。其中,第二方向权重矢量可以是对应于第二方向全向波束的权重矢量,也可以是已知的第二方向权重矢量。类似地,基站进行第二方向波束赋形训练或者基于第二方向子码本向用户发送训练序列在实现中也包括:基站基于第二方向子码本中的每个第二方向权重矢量与某个第一方向权重矢量的克罗内科积合成得到多组第一配置参数,再进行波束赋形训练。为了简化描述,下文在描述基站或用户设备的在一个方向上的波束赋形训练时不具体指出其中的克罗内科积合成步骤。
应指出,上文描述的步骤801和804可以合并为单个步骤,例如可以在步骤801中基站向用户设备指示第一方向波束赋形训练参数和第二方向波束赋形训练参数。
在实现中,这两个步骤801和804的实现可以合并为一条信令,在训练的第一步就发给用户,当然在两个方向上独立进行训练的时候这两个步骤801和804也分别作为单独的指令。
另外,优选地,此配置信令为专用信令,例如实现为无线电资源控制信令(radio resource control signaling)以为各个用户进行个性化的配置。
以上对于图8的描述仅仅是示例,并非作为限制。应指出,关于图8描述的过程中的一些实现,例如特定一组第一子配置参数、特定一组第二子配置参数、以及特定一组第一配置参数的确定可以如上文所述地那样进行替代性实现。
图8主要示出了当第一通信装置(例如,基站端)具有多个天线,特别是二维平面阵列天线(UPA)时利用本发明的波束赋形训练机制的流程图。在实际情况中,与第一通信装置通信的第二通信装置(例如,用户设备)也可能具有多个天线。此时,在接收到从第一通信装置发出的用于波束赋形训练的训练序列(例如导频信号)时,用于第二通信装置的特定一组配置参数(即,用于第二通信装置的最优的接收权重矢量)也需要被确定,例如从第二通信装置接收模拟码本中的各个接收权重矢量选择,以使得第一通信装置发出的信号能获得最佳的信道质量。这一过程在本申请的下文中也被称为接收波束扫描(sweeping)或者接收权重矢量扫描。经过接收波束扫描,用户设备可以固定以该最优的接收权重矢量进行后续通信。
因此,根据实施例,第二通信装置被配置为以多组第二配置参数接收来自第一通
信装置的信号传输,这样的接收可对应于接收波束扫描或者接收权重矢量扫描。用于配置所述第二通信装置的特定一组第二配置参数基于所述信号传输相关的信息被确定。
根据实施例,所述信号传输相关的信息是指示所述信号传输的通信信道质量的信息,并且其中所述特定一组第二配置参数是使得所述信号传输的通信信道质量最优的一组第二配置参数。应注意,所述信号传输相关的信息的含义与前文所述的第一传输相关的信息以及第二传输相关的信息的含义是相似的,因此其详细描述在此被省略。
根据实施例,特定一组第二配置参数可在第二通信装置处被确定,或者由第二通信装置之外的装置确定并反馈给第二通信装置。
根据实施例,所述信号传输可在第一传输和第二传输之前,例如可在图8的步骤802中的第一方向波束赋形训练之前,并且在此情况下,第一通信装置可以基于预定的一组第一配置参数配置所述信号传输。
根据实施例,所述信号传输可在第一传输和第二传输之后,例如可在图8的步骤805中的第二方向波束赋形训练之后,并且在此情况下,第一通信装置可以基于所确定的特定的一组第一子配置参数和所确定的特定的一组第二子配置参数配置所述信号传输。
根据实施例,所述信号传输可在第一传输和第二传输之间,例如,可以在图8的步骤802中的第一方向波束赋形训练与图8的步骤805中的第二方向波束赋形训练之间,并且在此情况下,第一通信装置可以基于所述特定一组第一子配置参数和预定的一组第二子配置参数配置所述信号传输。
根据实施例,所述信号传输可以是所述第一传输,例如可与图8的步骤802中的第一方向波束赋形训练同时进行,并且在此情况下,所述特定一组第二配置参数可以是通过如下方式确定的:在第一通信装置采用多组第一子配置参数中的每一个配置所述第一传输、而第二通信装置采用所述多组第二配置参数中的每一个来依次接收所述第一传输的情况下,选择使得对应的第一传输的信道通信质量最优的一组第二配置参数作为该特定一组第二配置参数。
根据实施例,所述信号传输可以是所述第二传输,例如可与图8的步骤805中的第二方向波束赋形训练同时进行,并且在此情况下,所述特定一组第二配置参数可以是通过如下方式确定的:在第一通信装置采用多组第二子配置参数中的每一个配置所述第二传输、而第二通信装置采用所述多组第二配置参数中的每一个来一次接收所述第二传输的情况下,选择使得对应的第二传输的通信信道质量最优的一组第二配置参
数作为该特定一组第二配置参数。
应指出,在第二通信装置(例如,用户设备)具有多天线的情况下,第二通信装置的多天线还可以是二维平面阵列天线。在此情况下,类似于第一通信装置的情况,用于第二通信装置的第二配置参数也可被分解成若干子配置参数,而可以分别确定各子配置参数并且组合所确定的子配置参数来重构最优的第二配置参数
根据实施例,第二通信装置的该特定一组第二配置参数是从特定的一组第三子配置参数和特定的一组第四子配置参数得到的,所述第三子配置参数和第四子配置参数分别与对应于第二通信装置的多个天线的平面的第三方向和第四方向相关联,并且第三方向和第四方向垂直,其中,所述特定的一组第三子配置参数是通过第二通信装置基于多组第三子配置参数接收来自第一通信装置的信号传输并且确定使得该信号传输的通信信道质量最优的一组第三子配置参数而被确定的,其中,所述特定的一组第四子配置参数是通过第二通信装置基于所确定的该组第三子配置参数以及多组第四子配置参数接收来自第一通信装置的信号传输并且确定使得该信号传输的通信信道质量最优的一组第四子配置参数而被确定的。
下面分别参照图9-图14中来说明上述的用于第二通信装置的第二配置参数的波束赋形过程。这样的描述是在第一通信装置为基站、第二通信装置为用户设备的前提下做出的,应指出这样的描述仅仅是示例性的,而非限制性的。
应指出,为了简化描述,在以后的针对图9-14的描述中省略了前述的基站为用户设备进行波束训练的专门配置的步骤,即步骤801和804。
在开始图9-图14的说明之前,先对其中将用到的全向(omni-direction)波束、水平全向波束和垂直全向波束进行说明。其中全向波束在所有水平和垂直到达角处具有实质上相同的增益,可以例如用公式表示为:
其中C为常数,一个典型全向波束例子为fomni=[1,0,…,0]T∈CN×1,其中N为天线数。
水平全向波束在所有水平到达角处具有实质上相同的增益,可以例如用公式表示为:
其中C(φ)为垂直到达角φ的函数,fv为任意垂直波束,一个典型水平全向波束例子为fh,omni=[1,0,…,0]T∈CW×1,其中W为水平方向天线数。
垂直全向波束在所有垂直到达角处具有实质上相同的增益。可以例如用公式表示为:
其中C(θ)为水平到达角θ的函数,fh为任意水平波束,一个典型垂直全向波束例子为fv,omni=[1,0,…,0]T∈CH×1,其中H为水平方向天线数。
应指出,上文描述的预定的一组第一配置参数可以对应于该全向波束,上文描述的预定的一组第二子配置参数可以对应于水平全向波束或者垂直全向波束。
图9a示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户的接收波束扫描在基站的第一方向波束赋形训练(即,上文所述的第一传输)之前。
如图9a所示,在步骤901,基站采用全向波束(即,预定的一组第一配置参数,对应于预定的一组第一子配置参数和预定的一组第二子配置参数)重复发送下行训练序列,扫描用户的模拟码本中的所有权重矢量。这里,训练序列的发送次数可以取决于用户的模拟码本的大小。例如,如果用户设备的模拟码本包括Q个权重矢量(即,用户设备的模拟码本大小为Q),则波束赋形训练序列需要被发送的次数大于或等于Q。
在步骤902,用户设备根据接收到的训练序列估计等效信道,并计算用户设备的最优接收权重矢量。该最优接收权重矢量可以是用户设备的模拟码本中使得信道质量最好的一个权重矢量。这可以用公式表示如下:
{wopt}=argmax|wTHfomni|s.t.w∈W
其中fomni为全向波束,wopt为最优接收权重矢量。
经过步骤902,用户设备将选择该最优的接收权重矢量作为后续的传输中将要使用的接收权重矢量(即,特定一组第二配置参数)。
在步骤903,基站采用水平全向波束(即,预定的一组第二子配置参数),扫描基站的垂直方向子码本(即,多组第一子配置参数)中的所有权重矢量,重复发送下行训练序列,用户采用在步骤902中确定的最优接收权重矢量进行接收。这里,训练序列的发送次数可以取决于基站的垂直方向子码本的大小。例如,如果用户设备的垂直方向子码本包括H个权重矢量(即,用户设备的垂直方向子码本大小为H),则波束赋形训练序列需要被发送的次数等于H。
在步骤904,用户根据接收到的训练序列估计等效信道,并计算基站的最优垂直方向权重矢量(即,特定一组第一子配置参数)。该最优垂直方向权重矢量可以是基站的垂直方向子码本中使得信道质量最好的一个垂直方向权重矢量。可用公式表示为:
其中fh,omni为水平全向波束,wopt为S41中训练得到的接收波束,fv,opt为最优垂直波束。
在步骤905,用户将在步骤904中确定的最优垂直方向权重矢量作为信道估计结果的反馈发送给基站。该信道估计结果的反馈可以是最优垂直方向权重矢量本身,也可以是该最优垂直方向权重矢量的索引。在一些情况下,该信道估计结果的反馈还可以仅仅是对应于基站的垂直方向子码本中的各个权重矢量的信道估计结果本身,基站在接收到这样的反馈后自己确定最优的垂直方向权重矢量。
在步骤906,基站采用在步骤904中确定的最优垂直方向权重矢量,扫描水平方向子码本(即,多组第二子配置参数)中的所有权重矢量,重复发送下行训练序列,用户仍然采用在步骤902中确定的最优接收权重矢量进行接收。这里,训练序列的发送次数可以取决于基站的水平方向子码本的大小。例如,如果用户设备的水平方向子码本包括W个权重矢量(即,用户设备的水平方向子码本大小为W),则波束赋形训练序列需要被发送的次数等于W。
在步骤907,用户根据接收到的训练序列估计等效信道,并计算基站的最优水平方向权重矢量(即,特定一组第二子配置参数)。该最优水平方向权重矢量可以是基站的水平方向子码本中使得信道质量最好的一个水平方向权重矢量。可用公式表示为:
其中wopt为步骤902中训练得到的接收波束,fv,opt为步骤904中训练得到的垂直方向权重矢量,fh,opt为最优水平方向权重矢量。
在步骤908,用户将在步骤907中确定的最优水平方向权重矢量作为信道估计结果的反馈发送给基站。同样,该信道估计结果的反馈可以是最优水平方向权重矢量本身或者其索引,也可以是信道估计结果本身。
至此,基站和用户设备间的下行波束赋形训练完成,所需的训练序列发送次数为Q+H+W。对比传统的波束赋形训练机制,如采用穷尽搜索机制,则训练序列发送次数为P×Q,其中P=H×W,为基站的模拟码本大小;如采用单次反馈搜索机制,则训练序列发送次数为P+Q。可见,相比传统的波束赋形训练机制,采用本发明的波束赋形
训练机制可以大大减小训练开销。
注意,在上面的流程中示出了基站先进行垂直方向波束扫描再进行水平方向波束扫描的情形,但是需认识到,基站也可以先进行水平方向波束扫描,再进行垂直方向波束扫描。此时的流程同图9a基本一致,只是在步骤903中基站采用垂直全向波束扫描水平方向子码本中的所有权重矢量,在此不做赘述。
图9b示出了图9a中步骤901(流程1)、903(流程2)和906(流程3)的示意图。也就是说,流程1表示的是基站采用全向波束发送,用户设备进行接收波束扫描;流程2表示的是基站采用水平全向波束进行垂直波束扫描,用户设备采用固定的最优接收波束;流程3表示的是基站采用最优的垂直波束进行水平波束扫描,用户设备采用固定的最优接收波束。
值得注意的是,在图9a、b所述的实施例中,基站采用全向波束发送而没有提供波束赋形增益,这将在某种程度上影响用户设备的接收波束训练。作为一个改进的示例,基站可以例如根据用户的粗略方位(例如通过现有的方向到达角估计、LBS等定位方案或GPS信息获得),在对应的方向上发送宽波束以提供一定的波束赋形增益,从而辅助用户接收波束扫描。例如,宽波束可以指的是在波束的增益集中在水平到达角和垂直到达角所有可能取值的较大范围内。
进一步地,应指出,在基站端发送全向波束进行训练时,这样没有提供波束赋形增益,有时可能会影响在用户设备处的波束训练。因此,作为一种变型实施例,可以考虑首先训练基站端的波束,然后再训练用户设备处的波束。以下将对此进行进一步的详细描述。
图10a示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户的接收波束扫描在基站的第一方向波束赋形训练(即,上文所述的第一传输)和第二方向波束赋形训练(即,上文所述的第二传输)之间。
如图10a所示,在步骤1001,基站采用水平全向波束,扫描基站的垂直方向子码本中的所有权重矢量,重复发送下行训练序列,用户采用全向波束进行接收。这里,训练序列的发送次数可以取决于基站的垂直方向子码本的大小。例如,如果用户设备的垂直方向子码本包括H个权重矢量(即,用户设备的垂直方向子码本大小为H),则波束赋形训练序列需要被发送的次数等于H。
在步骤1002,用户根据接收到的训练序列估计等效信道,并计算基站的最优垂直方向权重矢量。该最优垂直方向权重矢量可以是基站的垂直方向子码本中使得信道质
量最好的一个垂直方向权重矢量。可用公式表示为:
其中fh,omni为水平全向波束,womni为全向接收波束,fv,opt为最优垂直方向权重矢量。
在步骤1003,用户将在步骤1002中确定的最优垂直方向权重矢量作为信道估计结果的反馈发送给基站。该信道估计结果的反馈可以是最优垂直方向权重矢量本身或其索引。在一些情况下,该信道估计结果的反馈还可以仅仅是对应于基站的垂直方向子码本中的各个权重矢量的信道估计结果本身,基站在接收到这样的反馈后自己确定最优的垂直方向权重矢量。
在步骤1004,基站采用水平全向波束以及在步骤1002中确定的最优垂直方向权重矢量重复发送下行训练序列,扫描用户的模拟码本中的所有权重矢量。这里,训练序列的发送次数可以取决于用户的模拟码本的大小。例如,如果用户设备的模拟码本包括Q个权重矢量(即,用户设备的模拟码本大小为Q),则波束赋形训练序列需要被发送的次数等于Q。
在步骤1005,用户设备根据接收到的训练序列估计等效信道,并计算用户设备的最优接收权重矢量。该最优接收权重矢量可以是用户设备的模拟码本中使得信道质量最好的一个权重矢量。这可以用公式表示如下:
其中fh,omni为水平全向波束,fv,opt为步骤1002中训练得到的垂直波束,wopt为最优接收波束。
经过步骤1005,用户设备将选择该最优的接收权重矢量作为后续的传输中将要使用的接收权重矢量。
在步骤1006,基站采用在步骤1002中确定的最优垂直方向权重矢量,扫描水平方向子码本中的所有权重矢量,重复发送下行训练序列,用户采用在步骤1005中确定的最优接收权重矢量进行接收。这里,训练序列的发送次数可以取决于基站的水平方向子码本的大小。例如,如果用户设备的水平方向子码本包括W个权重矢量(即,用户设备的水平方向子码本大小为W),则波束赋形训练序列需要被发送的次数等于W。
在步骤1007,用户根据接收到的训练序列估计等效信道,并计算基站的最优水平方向权重矢量。该最优水平方向权重矢量可以是基站的水平方向子码本中使得信道质量最好的一个水平方向权重矢量。可用公式表示为:
其中wopt为步骤1005中训练得到的接收波束,fv,opt为步骤1002中训练得到的垂直方向权重矢量,fh,opt为最优水平方向权重矢量。
在步骤1008,用户将在步骤1007中确定的最优水平方向权重矢量作为信道估计结果的反馈发送给基站。同样,该信道估计结果的反馈可以是最优水平方向权重矢量本身或者其索引,也可以是信道估计结果本身。
至此,基站和用户设备间的下行波束赋形训练完成,所需的训练序列发送次数为H+Q+W。相比传统的波束赋形训练机制,采用本发明的波束赋形训练机制可以大大减小训练开销。
注意,在上面的流程中示出了基站先进行垂直方向波束扫描再进行水平方向波束扫描的情形,但是需认识到,基站也可以先进行水平方向波束扫描,再进行垂直方向波束扫描,在此不做赘述。
图10b示出了图10a中步骤1001(流程1)、1004(流程2)和1006(流程3)的示意图。也就是说,流程1表示的是基站采用水平全向波束进行垂直波束扫描,用户设备采用全向波束接收;流程2表示的是基站采用水平全向波束最优垂直波束,用户设备扫描接收波束;流程3表示的是基站采用最优的垂直波束进行水平波束扫描,用户设备采用固定的最优接收波束。
图11示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户的接收波束扫描在基站的第一方向波束赋形训练(即,上文所述的第一传输)和第二方向波束赋形训练(即,上文所述的第二传输)之后。
在步骤1101,基站采用水平全向波束,扫描基站的垂直方向子码本中的所有权重矢量,重复发送下行训练序列,用户采用全向波束接收。
在步骤1102,用户根据接收到的训练序列估计等效信道,并计算基站的最优垂直方向权重矢量。
在步骤1103,用户将在步骤1102中确定的最优垂直方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1104,基站采用在步骤1102中确定的最优垂直方向权重矢量,扫描水平
方向子码本中的所有权重矢量,重复发送下行训练序列,用户仍然采用全向波束进行接收。
在步骤1105,用户根据接收到的训练序列估计等效信道,并计算基站的最优水平方向权重矢量。
在步骤1106,用户将在步骤1105中确定的最优水平方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1107,基站基于在步骤1102中确定的最优垂直方向接收矢量和在步骤1105中确定的最优水平方向接收权重矢量,利用克罗内科积合成得到最优的权重矢量。
在步骤1108,基站采用在步骤1107得到的最优权重矢量重复发送下行训练序列,扫描用户的模拟码本中的所有权重矢量。
在步骤1109,用户根据接收到的训练序列估计等效信道,并计算用户的最优接收权重矢量。
采用图11的波束赋形训练机制所需的训练开销与与图9和图10中的波束训练机制的开销相同,都远远小于传统的波束赋形训练机制的训练开销。
以上对于图9-11的描述仅仅是示例,并非作为限制。应指出,关于图9-11描述的过程中的一些实现,例如特定一组第一子配置参数、特定一组第二子配置参数、以及特定一组第一配置参数的确定可以如上文所述地那样进行替代性实现。
上面的描述都是用户设备的接收波束扫描与基站的第一方向波束扫描和第二方向波束扫描分别单独进行的情形。
下面将通过图12-图13说明用户设备的接收波束扫描与基站的第一方向波束扫描(即,上述的第一传输)或第二方向波束扫描(即,上述的第二传输)同时进行时的操作流程。
图12a示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户的接收波束扫描在基站的第一方向波束赋形训练同时进行。以第一方向为水平方向,第二方向为垂直方向进行说明。
在步骤1201,基站采用垂直全向波束,并扫描基站的水平方向子码本中的所有权重矢量和用户的模拟码本中的所有权重矢量,重复发送下行训练序列。这里,训练序列的发送次数可以取决于基站的水平方向子码本和用户设备的模拟码本的大小。例如,如果基站的水平方向子码本包括W个权重矢量(即,基站的水平方向子码本大小为W),用户设备的模拟码本包括Q个权重矢量(即,用户设备的模拟码本大小为Q),则波
束赋形训练序列需要被发送的次数等于W×Q。
在步骤1202,用户根据接收到的训练序列来估计等效信道,并计算最优的权重矢量的组合。也就是说,根据训练序列,用户能够计算出:基站的水平方向子码本中的各个权重矢量与用户设备的模拟码本中的各个权重矢量的全部组合方式中,哪一种组合方式能够达到最好的信道质量。通过该计算,用户能够获得基站的最优水平方向权重矢量和用户的最优接收权重矢量。在后续的传输中,基站和用户设备将采用选定的这一对权重矢量进行传输。可用公式表示为
其中fv,omni为垂直全向波束,wopt为用户的最优接收权重矢量,fh,opt为基站的最优水平方向权重矢量。
在步骤1203,用户在步骤1202中确定的最优水平方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1204,基站采用在步骤1202中确定的最优水平方向权重矢量,扫描基站的垂直方向子码本中的所有权重矢量,重复发送下行训练序列,用户采用在步骤1202中确定最优权重矢量进行接收。这里,训练序列的发送次数可以取决于基站的垂直方向子码本的大小。例如,如果基站的垂直方向子码本包括H个权重矢量(即,基站的垂直方向子码本大小为H),则波束赋形训练序列需要被发送的次数等于H。
在步骤1205,用户根据接收到的训练序列来估计等效信道,计算基站的最优垂直方向权重矢量。也就是说,根据训练序列,用户能够计算出基站的垂直方向子码本中的各个垂直方向权重矢量中哪个垂直方向权重矢量能够达到最好的信道质量。可用公式表示为:
其中wopt为步骤1202中训练得到的接收权重矢量,fh,opt为步骤1202中训练得到的基站的最优水平方向权重矢量,fv,opt为基站的最优垂直方向权重矢量。
在步骤1206,用户将在步骤1205中确定的基站的最优垂直方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1207,基站基于在步骤1202中确定的最优水平方向接收矢量和在步骤1205中确定的最优垂直方向接收权重矢量,利用克罗内科积合成得到最优的权重矢量,以用于对用户设备的后续传输。
至此,已完成了基站和用户设备之间的下行波束赋形训练,其训练开销为
W×Q+H。由于基站的天线阵列通常大于用户端的天线数量,相应地,由基站的模拟码本拆分(decouple)得到的水平方向子码本和垂直方向子码本的大小也大于用户设备的模拟码本的大小。在这种情况下,利用图12所示的波束赋形训练机制能够减小波束训练开销。
图12b示出了图12a中步骤1201(流程1)和1204(流程2)的示意图。也就是说,流程1表示的是基站采用垂直全向波束进行水平波束扫描,用户设备进行接收波束扫描;流程2表示的是基站采用最优水平波束进行垂直波束扫描,用户设备利用最优接收波束进行接收。虽然在图12a和图12b中示出了流程1在流程2之前,但是本领域技术人员能够认识到,流程2也可以在流程1之前进行。
图13a示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户的接收波束扫描在基站的第二方向波束赋形训练同时进行。以第一方向为水平方向,第二方向为垂直方向进行说明。
在步骤1301,基站采用水平全向波束,并扫描基站的垂直方向子码本中的所有权重矢量和用户的模拟码本中的所有权重矢量,重复发送下行训练序列。这里,训练序列的发送次数可以取决于基站的垂直方向子码本和用户设备的模拟码本的大小。例如,如果基站的垂直方向子码本包括H个权重矢量(即,基站的水平方向子码本大小为H),用户设备的模拟码本包括Q个权重矢量(即,用户设备的模拟码本大小为Q),则波束赋形训练序列需要被发送的次数等于H×Q。
在步骤1302,用户根据接收到的训练序列来估计等效信道,并计算最优的权重矢量的组合。也就是说,根据训练序列,用户能够计算出:基站的垂直方向子码本中的各个权重矢量与用户设备的模拟码本中的各个权重矢量的全部组合方式中,哪一种组合方式能够达到最好的信道质量。通过该计算,用户能够获得基站的最优垂直方向权重矢量和用户的最优接收权重矢量。在后续的传输中,基站和用户设备将采用选定的这一对权重矢量进行传输。可用公式表示为:
其中fh,omni为水平全向波束,wopt为用户的最优接收权重矢量,fv,opt为基站的最优垂直方向权重矢量。
在步骤1303,用户在步骤1302中确定的最优垂直方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1304,基站采用在步骤1302中确定的最优垂直方向权重矢量,扫描基站
的水平方向子码本中的所有权重矢量,重复发送下行训练序列,用户采用在步骤1302中确定最优权重矢量进行接收。这里,训练序列的发送次数可以取决于基站的水平方向子码本的大小。例如,如果基站的水平方向子码本包括W个权重矢量(即,基站的水平方向子码本大小为W),则波束赋形训练序列需要被发送的次数等于W。
在步骤1305,用户根据接收到的训练序列来估计等效信道,计算基站的最优水平方向权重矢量。也就是说,根据训练序列,用户能够计算出基站的水平方向子码本中的各个水平方向权重矢量中哪个水平方向权重矢量能够达到最好的信道质量。可用公式表示为:
其中wopt为步骤1302中训练得到的用户的最优接收权重矢量,fv,opt为步骤1302中训练得到的基站的最优垂直方向权重矢量,fh,opt为基站的最优水平方向权重矢量。
在步骤1306,用户将在步骤1305中确定的基站的最优水平方向权重矢量作为信道估计结果的反馈发送给基站。
在步骤1307,基站基于在步骤1302中确定的最优垂直方向接收矢量和在步骤1305中确定的最优水平方向接收权重矢量,利用克罗内科积合成得到最优的权重矢量,以用于对用户设备的后续传输。
至此,已完成了基站和用户设备之间的下行波束赋形训练,其训练开销为H×Q+W。由于基站的天线阵列通常大于用户端的天线数量,相应地,由基站的模拟码本拆分得到的水平方向子码本和垂直方向子码本的大小也大于用户设备的模拟码本的大小。在这种情况下,利用图13所示的波束赋形训练机制能够减小波束训练开销。
本实施例在上述的步骤1202和1302中使用了穷尽搜索机制来确定基站的最优水平方向权重矢量和用户的最优接收权重矢量。但是,本申请的实施方式不限于这一实施例,本领域技术人员可以认识到,还可以使用现有技术中的多次反馈搜索机制或单次反馈搜索机制来进行步骤1302的波束训练过程。
可以看到,图13所示的波束赋形训练流程可以通过将图12中的水平方向换成垂直方向,将垂直方向换成水平方向来得到,其它配置参数可以保持基本一致。
图13b示出了图13a中步骤1301(流程1)和1304(流程2)的示意图。也就是说,流程1表示的是基站采用水平全向波束进行垂直波束扫描,用户设备进行接收波束扫描;流程2表示的是基站采用最优垂直波束进行水平波束扫描,用户设备利用最优接收波束进行接收。虽然在图13a和图13b中示出了流程1在流程2之前,但是本
领域技术人员能够认识到,流程2也可以在流程1之前进行。
以上对于图12-13的描述仅仅是示例,并非作为限制。应指出,关于图12-13描述的过程中的一些实现,例如特定一组第一子配置参数、特定一组第二子配置参数、以及特定一组第一配置参数的确定可以如上文所述地那样进行替代性实现。
上面的说明中并没有区分用户设备的天线是否为二维平面阵列天线,而是简单地整体考虑用户设备的模拟码本。事实上,当用户设备具有二维平面阵列天线时,为了进一步减小训练开销,还可以将用户设备的接收波束扫描拆分成第三方向波束扫描和与第三方向垂直的第四方向波束扫描,或者说将用户设备的模拟码本拆分成与第三方向子码本和第四方向子码本分开进行波束赋形训练。同基站的模拟码本拆分类似,用户设备的模拟码本也可以表示成第三方向子码本和第四方向子码本的克罗内科积的形式。第三方向和第四方向可以是相对于接收设备的天线阵列的平面的。本领域技术人员可以认识到,第三方向波束扫描和第四方向波束扫描可以与图9-图13中示出的基站的第一方向波束扫描和第二方向波束扫描进行各种组合,例如,可以与第一方向波束扫描和第二方向波束扫描分开进行,也可以与第一方向波束扫描和第二方向波束扫描中的任何一个同时进行。优选地,第一方向、第二方向、第三方向和第四方向的波束扫描分开进行,以尽可能大地减小训练开销。下面在图14中进行说明。
图14a示出了根据本发明的一个实施例的波束赋形训练的流程图,其中用户设备的接收波束扫描拆分成垂直方向接收波束扫描和水平方向接收波束扫描分开进行。
在步骤1401,基站采用全向波束重复发送下行训练序列,用户设备采用全向水平波束,扫描用户的垂直方向子码本中的所有权重矢量。用户的垂直方向子码本和用户的水平方向子码本可以预先存储与用户设备的存储器中,或者可以由用户设备基于预先存储于用户设备的存储器中的模拟码本进行拆分得到,或者可以由用户设备基于设备参数(例如,天线阵列尺寸)和/或通信协议约定直接确定。
在步骤1402,用户根据接收到的训练序列估计等效信道,并计算用户设备的最优垂直方向权重矢量。该最优垂直方向权重矢量可以是用户设备的垂直方向子码本中使得信道质量最好的一个垂直方向权重矢量。
在步骤1403,基站采用全向波束重复发送下行训练序列,用户设备采用在步骤1402中确定的最优垂直方向权重矢量,扫描用户的水平方向子码本中的所有权重矢量。
在步骤1404,用户根据接收到的训练序列估计等效信道,并计算用户设备的最优水平方向权重矢量。该最优水平方向权重矢量可以是用户设备的水平方向子码本中使
得信道质量最好的一个水平方向权重矢量。
在步骤1405,用户基于在步骤1402和1404分别确定的最优垂直方向权重矢量和最优水平方向权重矢量利用克罗内科积合成得到最优接收权重矢量,以用于与基站的后续通信。
步骤1406~1412与图9中的步骤903~909完全一致,在此不做赘述。
图14b示出了图14a中步骤1401(流程1)、1403(流程2)、1406(流程3)和1408(流程4)的示意图。也就是说,流程1表示的是基站采用全向波束发送,用户设备采用水平全向波束进行垂直波束扫描;流程2表示的是基站采用全向波束发送,用户设备采用最优垂直波束进行水平波束扫描;流程3表示的是基站采用水平全向波束进行垂直波束扫描,用户设备采用固定的最优接收波束;流程4表示的是基站采用最优的垂直波束进行水平波束扫描,用户设备采用固定的最优接收波束。
上面的实施例说明了用户的垂直波束扫描和水平波束扫描在基站的垂直波束扫描和水平波束扫描之前完成的情形。但是,本申请的具体实施方式不限于上面的实施例。本领域技术人员应当理解,这四个波束扫描过程可以以任意的次序分开进行,也可以将用户侧的两个波束扫描过程之一与基站侧的两个波束扫描过程之一组合起来同时进行。
在本申请所提出的各种波束赋形训练实施例中,波束训练可以采用周期或非周期的方案。周期方案中,基站和用户按一定的时间间隔进行一次波束赋形训练。在一些示例中,用户的接收波束训练、基站的水平方向波束训练、基站的垂直波束训练的周期可以不同。以图9b为例,流程1、流程2和流程3以不同周期出现,其中未参与训练的波束保持上一次训练的结果。又例如,由于用户垂直方向位移通常较小,因此基站垂直方向波束训练的时间间隔可以长于基站的水平方向波束训练。
在另一个示例中,基站通过历史波束训练过程或定位信息观测统计各个用户的运动规律,并相应地为各用户设置适当的训练周期,例如对垂直方向上很少移动且位移较小的用户设置较长的垂直方向波束训练周期,否则设置和水平方向波束训练等长的周期,从而保证训练结果的准确度。借此,可以在拆分出的特定方向上加长波束训练周期,相比于现有的波束训练方案训练开销进一步减小。例如,在两个T周期内与单次反馈机制反馈相比,单次反馈机制需要探测的权重矢量组合个数为2*(P+Q),其中P和Q分别为基站端和用户端码本大小,而在基站端码本可分解的情况下,P=W*H,则此非对称周期的训练方法的复杂度最低可少至2W+H+2Q。另一方面,可以理解,本
公开还支持在拆分出的特定方向例如水平方向上缩短波束训练周期,相比于现有的波束训练方案训练开销相似的或有限增加,但可以显著提高波束训练精度。
非周期方案中,用户发起波束赋形训练请求,基站处理用户请求后进行波束赋形训练。又或者,基站主动发起波束赋形训练要求,并配置用户执行波束赋形训练。
根据实施例,也可以周期性地或者非周期性地单独发起对用户的接收波束训练、基站的水平方向波束训练和基站的垂直方向波束训练的请求。单独波束赋形训练的情况可能发生在某些特殊场景下,例如当用户在单一方向上移动时,诸如用户乘坐电梯,沿垂直方向运动,则可以发起单独训练垂直方向波束的请求。
此外,在以上的描述中,在第一通信装置(例如,基站)进行的第一方向波束赋形使用了全部的第一方向子码本,和/或在第二方向波束赋形中使用了全部的第二方向子码本。然而,根据实施例,第一方向波束赋形和第二方向波束赋形可以分别使用部分的第一方向子码本和第二方向子码本。这种情况例如可发生于在进行波束赋形之前,已经进行预先处理来知晓用户的大概位置,例如大概的水平方向范围和/或大概的垂直方向范围,由此在训练中,可以使用对应于这样的水平方向范围的部分水平方向码本和/或对应于这样的垂直方向范围的部分垂直方向码本来进行波束赋形训练。
根据实施例,所述多组第一子配置参数和所述多组第二子配置参数均是预定范围内的子配置参数,其中,所述预定范围是全部可用子配置参数的范围的至少一部分。
此外,根据实施例,上述的全向波束、全向水平波束和全向垂直波束也可替换为其他波束。这种情况可能发生但不限于基站已知用户的大致位置,使用宽波束而不是全向波束进行训练。这里的宽波束可指的是在波束的增益集中在水平到达角和垂直到达角所有可能取值的较大范围内。作为一个改进的示例,基站可以例如根据用户的粗略方位(例如通过现有的方向到达角估计、LBS等定位方案或GPS信息获得),在对应的方向上发送宽波束以提供一定的波束赋形增益,从而辅助用户接收波束扫描。
本申请的波束赋形训练机制还可以拓展到多用户毫米波系统。以混合预编码架构下的多用户毫米波系统为例,每个射频链路服务一个用户,射频链路与对应用户间的波束赋形训练可利用图9a、10a、11、12a、13a和14a中所述的流程进行。但当多个射频链路和多个用户同时进行训练时,不同射频链路发送的训练序列应当是相互正交的以使得多个用户能够区分用于自身的信号。以图9的步骤901为例,假定基站端采用子连接混合预编码架构,配备K个射频链路,同时服务K个用户,Hi,j表示第i个射频链路与第j个用户间的信道矩阵,{φ1,φ2,…,φK}表示K个射频链路使用的正交序列。
其中yk表示第k个用户的接收信号,nk表示第k个用户的噪声,fomni表示基站采用全向波束发送,wk表示第k个用户的接收权重矢量。
在步骤902中,第k个用户采用最小二乘算法可以得到信道质量的估计:
也就是说,第k个用户将接收信道与针对第k个用户使用的第k个射频链路的训练序列的转置相乘来进行信道估计。相应的,对于第k个用户波束训练准则可以表示为:
其中wk,opt表示经过训练的用户的最优接收权重矢量,W表示模拟接收码本。
其他所有步骤可以使用相同的办法拓展到多用户毫米波系统。
图15示出了根据本发明的一个实施例将图9a所示的波束赋形训练流程拓展到多用户毫米波系统后的流程图。其中步骤1501~1509与图9a中的步骤901~909基本一致,不同的是基站具有针对多个用户的多个射频链路,每个射频链路发送彼此正交的训练序列。用户设备在接收到基站发送的信号后,基于相应的训练序列对接收到的信号进行处理后再进行信道估计。在基站向多个用户设备发送训练序列时,可以通过各个射频链路同时发送。而在多个用户设备进行信道估计后向基站反馈最优的权重矢量时,可以采用现有通信技术中各种已知的冲突避免机制,以保证各个反馈信号不会相互干扰。在一个示例中,用户设备在各自专属的物理上行控制信道上反馈最优权重矢量的索引。在另一个示例中,用户设备在MAC层或更高层例如以位图(bitmap)的形式进行反馈,每一位代表一个权重矢量,1表示相应位指示最优权重矢量,其他用0表示。相比于现有的波束赋形方案,本发明每次只需要使用少量比特即可分别反馈水平和垂直方向上的最优权重矢量,而可以避免对现有信令结构的改动,在一些场景下还可节约有限的信令资源。
本发明所提出的波束赋形机制还可以与信道状态估计机制结合使用。例如,在图15中,在步骤1509中基于最优垂直方向权重矢量和最优水平方向权重矢量利用克罗内科积计算得到基站的最优发送权重矢量后,基站可以在步骤1510利用步骤1509得到的最优发送权重矢量发送诸如信道状态信息参考信号(Channel State Information Reference Signal,CSI-RS)等的参考信号来估计信道状态信息。
在步骤1511,各个用户基于接收到的参考信号估计信道状态信息。在步骤1512,
各个用户将诸如预编码矩阵指示(Precoding Matrix Indicator,PMI)、信道质量指示(Channel Quality Indicator,CQI)等的信道状态信息反馈给基站。在步骤1513中,基站利用各个用户反馈的信道状态信息进行数字预编码以复用传输资源同时控制用户之间的干扰或确定调制编码方案等以进行用户调度。
为了进一步说明本发明,下面给出一个更具体的实施例。
考虑一个单小区多用户毫米波大规模天线系统,基站采用模数混合预编码架构同时服务K个用户,基站端配备K个射频链路。基站配备UPA天线阵列,天线数量M=W×H,其中W为天线阵列宽度方向上的天线数量,H为天线阵列高度方向上的天线数量。用户端采用ULA天线阵列。基站端和用户端均使用经典的DFT波束赋形码本设计方案,码本由如下码本矩阵确定
这里Na表示天线数,Nc表示码本大小,这里假定码本大小等于天线数。需要注意的是,由于基站端使用平面天线阵列,波束赋形码本由水平方向子码本和垂直方向子码本使用克罗内科积生成,水平方向子码本和垂直方向子码本为上述DFT码本。具体的系统仿真参数如下表所示:
表1仿真具体参数
考虑传统的穷尽搜索机制,波束赋形训练的开销为MN个OFDM符号。单次反馈搜索机制的波束赋形训练开销为M+N个OFDM符号。而在我们提出的基于第一方向和第二方向分开进行波束赋形训练的机制可以将训练开销降低。例如,采用图9的波束赋
形训练机制的开销为W+H+N个OFDM符号,采用图12和图13的波束赋形训练机制的开销分别为H+W×N或W+H×N个OFDM符号。具体如下表所示。
表2不同波束赋形训练机制的训练开销比较
训练机制 | 训练开销 |
穷尽搜索 | MN=256 |
单次反馈 | M+N=68 |
图9所示机制 | W+H+N=20 |
图12所示机制 | H+W×N=40 |
图13所示机制 | W+H×N=40 |
为了验证提出的波束赋形训练机制的性能,下面对用户平均可达速率进行仿真,供考虑五种方案,分别是:(1)穷尽搜索机制;(2)单次反馈搜索机制;(3)图9所示机制;(4)图12所示机制;(5)图13所示机制。
图16给出了单用户场景下各个波束训练机制用户可达速率仿真,可以看到与传统的单次反馈机制相比,图9所示机制性能损失很小(约1dB),然而训练开销由68个时隙降低到20个时隙,降低了约70%。此外,图12所示机制和图13所示机制的性能与单次反馈接近,但训练开销也降低了约40%。证明所提出的波束赋形训练机制能够大大降低训练开销,同时获得良好的性能。
图17给出了多用户场景下各个波束训练机制用户平均可达速率仿真,类似于单用户场景,可以看到所提出的波束赋形训练机制能够大大降低训练开销,同时获得良好的性能。
<应用示例>
本公开内容的技术能够应用于各种产品。例如,基站可以被实现为任何类型的演进型节点B(eNB),诸如宏eNB和小eNB。小eNB可以为覆盖比宏小区小的小区的eNB,诸如微微eNB、微eNB和家庭(毫微微)eNB。代替地,基站可以被实现为任何其他类型的基站,诸如NodeB和基站收发台(BTS)。基站可以包括:被配置为控制无线通信的主体(也称为基站设备,例如本申请中描述的电子设备700和710);以及设置在与主体不同的地方的一个或多个远程无线头端(RRH)。另外,下面将描述的各种类型的终端均可以通过暂时地或半持久性地执行基站功能而作为基站工作。
例如,终端设备可以被实现为移动终端(诸如智能电话、平板个人计算机(PC)、笔记本式PC、便携式游戏终端、便携式/加密狗型移动路由器和数字摄像装置)或者车载终端(诸如汽车导航设备)。终端设备还可以被实现为执行机器对机器(M2M)通信的终端(也称为机器类型通信(MTC)终端)。此外,终端设备可以为安装在上述终端中的每个终端上的无线通信模块(诸如包括单个晶片的集成电路模块,例如本申请中描述的电子设备700和710)。
图18示出了一种根据本发明的电子设备的硬件配置的示例。
中央处理单元(CPU)2301起到基于存储在只读存储器(ROM)1802或存储单元1808上的程序执行各类处理的数据处理单元的作用。例如,CPU 1801执行基于前述序列的处理。随机存取存储器(RAM)1803存储由CPU 1801执行的程序、数据等。CPU 1801、ROM 1802和RAM 1803经由总线1804彼此相连。
CPU 1801经由总线1804连接至输入和输出接口1805,并且由各类开关、键盘、鼠标、麦克风等构成的输入单元1806和由显示器、扬声器等构成的输出单元1807连接至该输入和输出接口1805。例如,CPU 1801响应于从输入单元1806输入的指令执行各类处理,并将处理结果输出至输出单元1807。
连接至输入和输出接口1805的存储单元1808例如由硬盘构成,并且在其上存储由CPU 1801执行的程序以及各类数据。通信单元1809经由诸如因特网或局域网的网络与外部设备通信。
连接至输入和输出接口1805的驱动器1810驱动诸如磁盘、光盘、磁光盘或者半导体存储器(例如存储卡)的之类的可移除介质1811,并且获取其上记录的诸如内容和密钥信息的各类数据。例如,通过使用获取的内容和密钥数据,由CPU 1801基于再现程序执行用于无线通信的波束赋形训练等处理。
可能以许多方式来实现本发明的方法和系统。例如,可通过软件、硬件、固件或者软件、硬件、固件的任何组合来实现本发明的方法和系统。用于所述方法的步骤的上述顺序仅是为了进行说明,本发明的方法的步骤不限于以上具体描述的顺序,除非以其它方式特别说明。此外,在一些实施例中,还可将本发明实施为记录在记录介质中的程序,这些程序包括用于实现根据本发明的方法的机器可读指令。因而,本发明还覆盖存储用于执行根据本发明的方法的程序的记录介质。
至此,已经详细描述了根据本发明的波束赋形训练方法以及用于基站和用户设备的电子设备。为了避免遮蔽本发明的构思,没有描述本领域所公知的一些细节。本领域技术人
员根据上面的描述,完全可以明白如何实施这里公开的技术方案。
可能以许多方式来实现本发明的方法和系统。例如,可通过软件、硬件、固件或者软件、硬件、固件的任何组合来实现本发明的方法和系统。用于所述方法的步骤的上述顺序仅是为了进行说明,本发明的方法的步骤不限于以上具体描述的顺序,除非以其它方式特别说明。此外,在一些实施例中,还可将本发明实施为记录在记录介质中的程序,这些程序包括用于实现根据本发明的方法的机器可读指令。因而,本发明还覆盖存储用于执行根据本发明的方法的程序的记录介质。
虽然已经通过示例对本发明的一些特定实施例进行了详细说明,但是本领域的技术人员应该理解,以上示例仅是为了进行说明,而不是为了限制本发明的范围。本领域的技术人员应该理解,可在不脱离本发明的范围和精神的情况下,对以上实施例进行修改。本发明的范围由所附权利要求来限定。
Claims (33)
- 一种用于无线通信系统的第一通信装置的电子设备,其中,第一通信装置布置有多个天线,所述电子设备包括:处理电路,被配置为:基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
- 根据权利要求1所述的电子设备,其中,所述多组第一子配置参数中的每一组用于配置与所述多个天线一一对应的一组移相器中的多个移相器的相位值,和/或其中,所述多组第二子配置参数中的每一组用于配置所述一组移相器中的多个移相器的相位值,和/或其中,所述特定一组第一配置参数配置所述一组移相器中的每个移相器的相位值。
- 根据权利要求1所述的电子设备,其中,所述第一传输相关的信息是指示所述第一传输的通信信道质量的信息,并且其中,所述特定一组第一子配置参数是使得所述第一传输的通信信道质量最优的一组第一子配置参数;和/或其中,所述第二传输相关的信息是指示所述第二传输的通信信道质量的信息,并且其中,所述特定一组第二子配置参数是使得所述第二传输的通信信道质量最优的一组第二子配置参数。
- 根据权利要求1所述的电子设备,其中,所述第一传输相关的信息指示使得所述第一传输的通信信道质量最优的一组第一子配置参数或者该一组第一子配置参数的索引;和/或其中,所述第二传输相关的信息指示使得所述第二传输的通信信道质量最优的一组第二子配置参数或者该一组第二子配置参数的索引。
- 根据权利要求1所述的电子设备,其中,基于多组第一子配置参数分别配置所述第一传输包括:基于多组第一子配置参数和预定的一组第二子配置参数来配置所述第一传输。
- 根据权利要求1所述的电子设备,其中,基于多组第二子配置参数分别配置所述第二传输包括:基于所述特定一组第一子配置参数和多组第二子配置参数来配置所述第二传输。
- 根据权利要求1所述的电子设备,其中,所述多组第一组子配置参数和所述多组第二组子配置参数预先存储于第一通信装置的存储器中,或者从预先存储于第一通信装置的存储器中的多组第一配置参数得出。
- 根据权利要求1所述的电子设备,其中,所述电子设备工作为第一通信装置,该第一通信装置还包括射频链路和与所述多个天线一一对应的一组移相器,其中该组移相器设置于所述射频链路与所述多个天线之间,其中,所述电子设备的处理电路基于所述特定一组第一配置参数来配置所述一组移相器的相位值。
- 根据权利要求1所述的电子设备,其中,第二通信装置被配置为以多组第二配置参数接收来自第一通信装置的信号传输,并且其中,用于配置所述第二通信装置的特定一组第二配置参数基于所述信号传输相关的信息被确定。
- 根据权利要求9所述的电子设备,其中,所述信号传输相关的信息是指示所述信号传输的通信信道质量的信息,并且其中所述特定一组第二配置参数是使得所述信号传输的通信信道质量最优的一组第二配置参数。
- 根据权利要求10所述的电子设备,其中,所述信号传输在第一传输和第二传输之前,并且第一通信装置基于预定的一组第一配置参数配置所述信号传输。
- 根据权利要求10所述的电子设备,其中,所述信号传输在第一传输和第二传输之后,并且第一通信装置基于所述特定的一组第一子配置参数和所述特定的一组第二子配置参数配置所述信号传输。
- 根据权利要求10所述的电子设备,其中所述信号传输在第一传输和第二传输之间,并且第一通信装置基于所述特定一组第一子配置参数和预定的一组第二子配置参数配置所述信号传输。
- 根据权利要求10所述的电子设备,其中,所述信号传输是所述第一传输,并且所述特定一组第二配置参数是通过如下方式确定的:在第一通信装置采用多组第一子配置参数中的每一个配置所述第一传输、而第二通信装置采用所述多组第二配置参数中的每一个来依次接收所述第一传输的情况下,选择使得对应的第一传输的信道通信质量最优的一组第二配置参数作为该特定一组第二配置参数。
- 根据权利要求10所述的电子设备,其中,所述信号传输是所述第二传输,并且所述特定一组第二配置参数是通过如下方式确定的:在第一通信装置采用多组第二子配置参数中的每一个配置所述第二传输、而第二通信装置采用所述多组第二配置参数中的每一个来一次接收所述第二传输的情况下,选择使得对应的第二传输的通信信道质量最优的一组第二配置参数作为该特定一组第二配置参数。
- 根据权利要求10所述的电子设备,其中,第二通信装置的该特定一组第二配置参数是从特定的一组第三子配置参数和特定的一组第四子配置参数得到的,所述第三子配置参数和第四子配置参数分别与对应于第二通信装置的多个天线的平面的第三方向和第四方向相关联,并且第三方向和第四方向垂直,其中,所述特定的一组第三子配置参数是通过第二通信装置基于多组第三子配置 参数接收来自第一通信装置的信号传输并且确定使得该信号传输的通信信道质量最优的一组第三子配置参数而被确定的,其中,所述特定的一组第四子配置参数是通过第二通信装置基于所确定的该组第三子配置参数以及多组第四子配置参数接收来自第一通信装置的信号传输并且确定使得该信号传输的通信信道质量最优的一组第四子配置参数而被确定的。
- 根据权利要求1所述的电子设备,其中,所述多组第一子配置参数和所述多组第二子配置参数均是预定范围内的子配置参数,其中,所述预定范围是全部可用子配置参数的范围的至少一部分。
- 根据权利要求1所述的电子设备,其中,所述通信系统包括多个第二通信装置,所述第一传输和第二传输基于与所述多个第二通信装置对应的彼此正交的多个导频信号被进行,在进行第一传输之前,所述处理电路还被配置为向所述多个第二通信装置中的每一个发送所述多个导频信号中的对应的一个。
- 根据权利要求1所述的电子设备,第一通信装置还包括多个射频链路,其中每一射频链路与一组移相器相耦接,第一通信装置还包括与所述多个射频链路耦接的数字预编码器。
- 如权利要求19所述的电子设备,所述处理电路还被配置为基于来自与多个第二通信装置的之间信道状态信息生成数字预编码矩阵,以便所述数字预编码器对用于所述多个第二通信装置的数据信号进行数字预编码。
- 如权利要求1所述的电子设备,其中第一传输和第二传输由第一通信装置按周期性的时间间隔发起。
- 如权利要求21所述的电子设备,其中用于第一传输的时间间隔与用于第二传输的时间间隔不同。
- 如权利要求1所述的电子设备,其中第一传输和第二传输基于来自第二通信 装置的非周期性的请求发起。
- 如权利要求23所述的电子设备,其中,第一传输和第二传输是基于来自第二通信装置的请求单独发起的。
- 一种用于无线通信系统的第二通信装置的电子设备,其中,所述电子设备包括处理电路,被配置为:获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
- 根据权利要求25所述的电子设备,其中,获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息包括:获取由第一通信装置基于多组第一子配置参数和预定的一组第二子配置参数配置的第一传输的通信信道质量的信息;其中,所述特定一组第一子配置参数是使得所述第一传输的通信信道质量最优的一组第一子配置参数。
- 根据权利要求25所述的电子设备,其中,获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息包括:获取由第一通信装置基于所述特定一组第一子配置参数和多组第二子配置参数来配置的所述第二传输的通信信道质量的信息;其中,所述特定一组第二子配置参数是使得所述第一传输的通信信道质量最优的 一组第二子配置参数。
- 根据权利要求25所述的电子设备,其中,所述处理电路还被配置为:以多组第二配置参数接收来自第一通信装置的信号传输;对于所述信号传输进行通信信道质量估计;从所述多组第二配置参数中确定使得通信信道质量估计结果最优的特定一组第二配置参数。
- 一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括:基于多组第一子配置参数分别配置第一通信装置对第二通信装置的第一传输,使得特定一组第一子配置参数基于所述第一传输相关的信息被确定,其中所述多组第一子配置参数与相对于所述多个天线的平面的第一方向相关联;基于多组第二子配置参数分别配置第一通信装置对第二通信装置的第二传输,使得特定一组第二子配置参数基于所述第二传输相关的信息被确定,其中所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;并且基于特定一组第一配置参数配置第一通信装置对第二通信装置的后续传输,其中,所述特定一组第一配置参数是基于所述特定一组第一子配置参数和所述特定一组第二子配置参数的组合被确定的。
- 一种用于无线通信系统的方法,其中,所述无线通信系统包含第一通信装置和第二通信装置,所述第一通信装置布置有多个天线,所述方法包括:获取由第一通信装置基于多组第一子配置参数分别配置的第一传输相关的信息,其中多组第一子配置参数与相对于第一通信装置的多个天线的平面的第一方向相关联;以及获取由第一通信装置基于多组第二子配置参数分别配置的第二传输相关的信息,所述多组第二子配置参数与相对于所述平面的第二方向相关联,所述第二方向与第一方向正交;其中,根据基于所述第一传输相关的信息被确定的特定一组第一子配置参数和基于所 述第二传输相关的信息被确定的特定一组第二子配置参数确定用于配置第一通信装置对第二通信装置的后续传输的特定一组第一配置参数。
- 一种设备,包括:一个或多个处理器,以及一个或多个存储设备,包括指令,所述指令在被所述一个或多个处理器执行时使得执行根据权利要求29或30所述的方法。
- 一种用于执行根据权利要求29或30所述的方法的部件的装置。
- 一种存储介质,存储有指令,所述指令当被处理器执行时导致执行根据权利要求29或30所述的方法。
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