WO2018196505A1 - 星座图旋转方法及装置 - Google Patents

星座图旋转方法及装置 Download PDF

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Publication number
WO2018196505A1
WO2018196505A1 PCT/CN2018/079538 CN2018079538W WO2018196505A1 WO 2018196505 A1 WO2018196505 A1 WO 2018196505A1 CN 2018079538 W CN2018079538 W CN 2018079538W WO 2018196505 A1 WO2018196505 A1 WO 2018196505A1
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constellation
rotation angle
received signal
base station
constellation rotation
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PCT/CN2018/079538
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English (en)
French (fr)
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叶能
李详明
陈晓航
侯晓林
赵群
蒋惠玲
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株式会社Ntt都科摩
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Priority to CN201880024261.3A priority Critical patent/CN110506412B/zh
Priority to US16/608,728 priority patent/US11362879B2/en
Publication of WO2018196505A1 publication Critical patent/WO2018196505A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/3405—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
    • H04L27/3444—Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power by applying a certain rotation to regular constellations
    • 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
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/18—Phase-modulated carrier systems, i.e. using phase-shift keying
    • H04L27/20—Modulator circuits; Transmitter circuits
    • H04L27/2032—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner
    • H04L27/2053—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases
    • H04L27/206—Modulator circuits; Transmitter circuits for discrete phase modulation, e.g. in which the phase of the carrier is modulated in a nominally instantaneous manner using more than one carrier, e.g. carriers with different phases using a pair of orthogonal carriers, e.g. quadrature carriers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0037—Inter-user or inter-terminal allocation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0058—Allocation criteria
    • H04L5/0073—Allocation arrangements that take into account other cell interferences
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices

Definitions

  • the present application relates to the field of mobile communication technologies, and in particular, to a constellation rotation method and apparatus in a multi-user access technology.
  • the non-orthogonal multiple access (NOMA) technology can significantly improve the uplink and downlink transmission performance of the cell edge users and the throughput of the system. Moreover, according to the information theory, the transmission performance and throughput of the NOMA system can be further improved by adjusting the constellation rotation angle of the user terminal (UE). To this end, it is necessary to study how to determine the constellation rotation angle of the UE to optimize the transmission performance and throughput of the NOMA system.
  • UE user terminal
  • An example of the present application proposes a constellation rotation method.
  • the method includes determining a statistical characteristic of a received signal of a base station according to channel coefficients, noise information, and/or interference information of one or more user equipment UEs, wherein the received signal is the received by the base station through a physical channel a signal transmitted by one or more UEs; determining a constellation rotation angle of each UE according to the determined statistical characteristics of the received signals; and rotating the constellation of the one or more UEs according to a constellation rotation angle of each UE .
  • An example of the present application also proposes a constellation rotation method.
  • the method includes determining a statistical characteristic of a received signal of a base station according to channel coefficients, noise information, and/or interference information of one or more user equipment UEs, wherein the received signal is the received by the base station through a physical channel a signal transmitted by one or more UEs; determining a constellation rotation angle of each UE according to the determined statistical characteristics of the received signals; and respectively notifying each UE of a constellation rotation angle of each UE.
  • An example of the present application also proposes a constellation rotation method.
  • the method includes: receiving, from a base station, its own constellation rotation angle, wherein the constellation rotation angle is determined by a base station according to a statistical characteristic of a received signal, and the received signal is one received by the base station through a physical channel or a signal transmitted by a plurality of user equipment UEs; the base station determines a statistical characteristic of the received signal according to channel coefficients, noise information, and/or interference information of one or more UEs; and a constellation of its own according to the constellation rotation angle The figure is rotated.
  • the base station includes:
  • the memory readable instruction module is stored in the memory;
  • the machine readable instruction module includes:
  • a model establishing module configured to determine a statistical feature of a received signal of a base station according to channel coefficients, noise information, and/or interference information of one or more UEs, where the received signal is the received by the base station through a physical channel a signal transmitted by one or more UEs;
  • the constellation rotation angle determining module is configured to respectively determine a constellation rotation angle of each corresponding UE according to the determined statistical characteristics of the received signals.
  • examples of the present application also provide a computer readable storage medium having computer instructions stored thereon, wherein the computer instructions are executed by a processor to implement the steps of any of the above methods.
  • FIG. 1 shows an example of an access network side of a wireless communication system according to an example of the present application
  • FIG. 3 shows a process of processing a downlink data stream by a base station according to an example of the present application
  • Figure 5 shows an example of downlink signaling
  • FIG. 6 shows a process of processing a uplink data stream by a UE according to an example of the present application
  • FIG. 7 is a schematic structural view of a constellation rotation device according to an example of the present application.
  • Figure 8 is a block diagram showing the structure of a constellation rotation device according to an example of the present application.
  • FIG. 9 is a schematic structural diagram of hardware of a radio base station and a user terminal according to an example of the present application.
  • the transmission performance and throughput of the NOMA system can be further improved by adjusting the constellation rotation angle of the UE.
  • How to determine the UE's constellation rotation angle to maximize the throughput of the system is a very complicated problem.
  • all possible constellation rotation angles can be traversed in an exhaustive way, and the constellation rotation angle that makes the system performance optimal can be found out.
  • such a processing method has a very high computational complexity.
  • the base station requires a large amount of hardware resources for calculation and storage, and the flexibility is also very poor, and is not suitable for real-time service applications.
  • an example of the present application proposes a constellation rotation method that can be used to determine the angle of rotation of each UE constellation of the upper and lower directions.
  • the method proposed in the application example considers small-scale channel information such as channel coefficients of the UE, and also considers large-scale channel information such as the signal-to-noise ratio of the UE. Therefore, the determined constellation rotation angle of the UE is in various signal and noise modes. Good system performance and throughput can be obtained under different conditions, and the computational complexity of the method is very small, which can reduce the calculation amount of the base station, reduce the calculation delay and the power consumption of the base station, and also reduce the base station. Computational and storage requirements for hardware resources.
  • FIG. 1 shows an example of an access network side of a wireless communication system according to an example of the present application.
  • the wireless communication system described in the example of the present application may include at least one base station (BS) and at least two UEs, such as UE1 and UE2.
  • the UE1 and the UE2 can access the foregoing BS through a non-orthogonal multiple access (NOMA) mode. Since UE1 and UE2 multiplex the same time-frequency resources in a non-orthogonal manner, the transmission performance and throughput of the system can be improved by performing constellation rotation on the UE.
  • NOMA non-orthogonal multiple access
  • the constellation rotation angle of UE1 is (Equivalent to the rotation angle of the constellation diagram of UE1 with reference to the constellation diagram of UE2 is ), then the signal received by the base station at this time can be as shown in the following formula (1).
  • the received signal of the base station x 1 is the signal that the transmitted signal passes through the physical channel (ie, after attenuation and fading) after the UE1 is not rotated by the constellation (the signal is actually the UE1 modulation symbol multiplied by the channel coefficient). ); After the signal constellation rotates UE1, signals transmitted after physical channel seen at the base station side; x 2 UE2 signal is transmitted after physical channel seen at the base station side; The rotation angle of the constellation of UE1 relative to its original constellation.
  • the distribution function is Distribution function It is uniquely determined by the channel coefficients of the UE(s), the transmission constellation of the UE(s), and the rotation angle of the UE(s) constellation.
  • Representative random variable The distribution function is Where the distribution function The channel coefficient of UE1, the transmission constellation of UE1 and the rotation angle of UE1 are uniquely determined.
  • the distribution function representing the random variable x 2 is Distribution function The channel coefficient of UE2 is uniquely determined by the transmission constellation of UE2. Representing the random variable n 0,r satisfies the cyclic symmetric complex Gaussian noise distribution function
  • a random variable that is a signal at the receiving end For all possible a collection of components; X 2 is a collection of all possible x 2 components; For collection The number of elements in the set,
  • the main problem to be solved by the examples in this application is how to determine the above.
  • the value maximizes the throughput of the system, thereby achieving the goal of optimizing the transmission performance of the system as much as possible.
  • a mixed Gaussian model is proposed, and a mixed Gaussian model is constructed for the random variables of the above-mentioned receiver signals to obtain a received signal random variable based on the mixed Gaussian model. It can be seen that its distribution function can be as shown in the following formula (2):
  • a random variable representing the signal at the receiving end Rotation angle for UE1 constellation a signal that is transmitted at the receiving end after the transmitted signal passes through the physical channel; Is a set of constellation points that are visible at the receiving end after all possible constellation points sent by UE1 pass through the physical channel; Rotate the angle for the UE2 constellation a signal that is transmitted by the post-transmitted signal at the base station after passing through the physical channel; Is a set of constellation points that are visible at the receiving end after all possible constellation points sent by UE2 pass through the physical channel; Rotation angle for UE N constellation a signal that is transmitted at the receiving end after the transmitted signal passes through the physical channel; Is a set of constellation points that are visible to the receiving end after all possible constellation points sent by the UE N pass through the physical channel; N is the number of UEs; For collection The number of elements in the For collection The number of elements in ; It is the noise variance; I is the unit diagonal matrix; and CN(u,v) is
  • the distribution function of the above-mentioned mixed Gaussian model-based received signal random variable can be expressed by the following formula (3):
  • the distribution function of the received signal random variable based on the mixed Gaussian model may be expressed by the following formula (4):
  • the random variable of the received signal obtained by the above mixed Gaussian model is both small-scale channel information such as the channel coefficient of the UE ( It is related to the large-scale channel information such as the signal-to-noise ratio of the UE (the variance ⁇ 2 of the Gaussian model represents the noise of the UE channel) in relation to x 2,k including small-scale information such as channel coefficients.
  • the entropy of the random variable of the received signal can be determined according to the distribution function of the random variable of the received signal.
  • the random variable Y is represented in uppercase and is mainly used to distinguish it from the integral variable y.
  • the constellation rotation angle that maximizes the entropy of the received signal random variable can be solved according to its distribution function, and It serves as the rotation angle of the UE constellation.
  • the above-mentioned mixed Gaussian model-based received signal random variable takes into account both the influence of noise and the amplitude of different constellation points, that is, considering both the noise situation and the channel coefficient of the UE, and thus, obtained therefrom
  • the value can be applied to different signal-to-noise ratio cases and different constellation diagrams. High accuracy can be obtained in the case of high signal-to-noise ratio or low signal-to-noise ratio. Therefore, the flexibility of the method is very high. A very wide range of signal to noise ratios.
  • the method does not limit the form of the constellation, and can be applied to various complex constellation forms such as quadrature amplitude modulation (QAM) and the like.
  • QAM quadrature amplitude modulation
  • C is a constant; Represents the distance between two constellation points.
  • representative representative X stands for X JK representative X LM representative t represents the number of antennas; ⁇ 2 represents noise.
  • the lower bound expression of the entropy of the received signal random variable based on the mixed Gaussian model is a closed expression, which can also be called a closed lower bound expression, so the solution makes it maximize of
  • the computational complexity of the value is very low, only O(1), which is basically independent of the rotation angle parameter of the constellation. Therefore, the hardware resource requirements for calculation and storage of the base station are very low, and the calculation delay is also small, which is more suitable. For real-time applications.
  • the application environment of the above idea can be further extended to the case where the noise and/or interference is non-Gaussian, and the mixed Gaussian model is extended to a non-Gaussian environment, which may also be called a hybrid model.
  • you can use the distribution function of noise and / or interference In place of the above formula (2), (3) or (4)
  • the following formula (6) is obtained as a distribution function of the random variable of the received signal in a non-Gaussian environment, and the entropy of the random variable of the received signal can be calculated accordingly:
  • each parameter can refer to the description of formula (2).
  • the M-th order center distance of the received signal for example, the 2nd order center distance (ie, the variance).
  • M is a natural number greater than or equal to 2.
  • the M-th order center distance of the received signal can be used as a sub-optimal approximation of the entropy of the received signal random variable.
  • the present application proposes a constellation rotation method.
  • the method can be applied to downlink data transmission and can be performed by a base station.
  • Figure 2 shows the constellation rotation method for downlink data transmission. As shown in Figure 2, the method includes:
  • Step 201 The base station determines a statistical feature of the received signal according to channel coefficients, noise information, and/or interference information of one or more UEs.
  • the statistical feature of the received signal may specifically refer to an entropy of a received signal random variable determined by the base station according to channel coefficients, noise information, and/or interference information of one or more UEs.
  • the multi-user signal may be modeled as a mixed Gaussian model.
  • the statistical feature of the received signal may specifically refer to a channel coefficient of the base station according to one or more UEs. Noise information and/or interference information and the entropy of the received signal random variable determined based on the mixed Gaussian/non-Gaussian model.
  • the base station may separately acquire channel coefficients of multiple UEs through channel measurement.
  • channel noise in some examples of the present application, fixed channel noise may be employed or set according to the current system or channel conditions, for example, set to -110 dBm.
  • determining the entropy of the received signal random variable may include the following two steps: determining a distribution function of the received signal random variable; and determining the received signal random variable according to a distribution function of the received signal random variable entropy.
  • the received signal random variable is a variant of the received signal random variable seen by the base station side, and the distribution function may refer to the above formula (2), (3), (4) or (6), that is, according to each UE.
  • the distribution function of the random variables of the received signal is determined by the number of elements in the set of constellation points and the distribution function of noise and/or interference seen by all possible constellation points after passing through the physical channel at the receiving end.
  • the distribution function of the received signal random variable is associated with small-scale channel information (e.g., channel coefficients) of the UE and large-scale channel information (e.g., statistical values of signal-to-noise ratio).
  • the distribution function of noise and/or interference is a cyclic symmetric Gaussian distribution function in which the sum of the signals of the respective UEs seen by the receiving end is mean and the variance of the noise is a variance.
  • the entropy of the received signal random variable based on the mixed Gaussian model can be obtained by the above distribution function.
  • an expression of the entropy of the received signal random variable may be approximated to obtain a closed lower bound expression of the entropy of the received signal random variable, and received.
  • the closed lower bound expression of the entropy of the signal random variable is taken as the entropy of the random variable of the received signal.
  • the above closed lower limit expression may be as shown in the above formula (5).
  • the statistical feature of the received signal may specifically refer to an M-th order center distance of the received signal determined by the base station according to channel coefficients, noise information, and/or interference information of one or more UEs, where , M is a natural number greater than or equal to 2.
  • Step 202 The base station determines the constellation rotation angle of each UE according to the statistical characteristics of the received signal.
  • the random variable of the received signal is a variant of the random variable of the received signal seen by the base station side. It can be proved by reasoning that when the entropy of the random variable of the received signal is maximum, the throughput of the system can reach the maximum or the approximate maximum. .
  • the entropy of the received signal random variable may be taken as the above statistical feature, and the constellation rotation angle when the entropy of the received signal random variable is maximized may be solved and used as the constellation diagram of each corresponding UE. Rotation angle.
  • the M-th order center distance of the received signal may be used as a sub-optimal approximation of the entropy of the received signal random variable, that is, the M-th order center distance of the received signal may be used as the above statistical feature, and solved.
  • the constellation rotation angle of the M-th order center distance of the received signal is made to be the rotation angle of the constellation of each corresponding UE.
  • step 201 and step 202 the constellation rotation angle of each UE can be determined separately. That is, the above steps 201 and 202 provide a method for determining the rotation angle of the constellation, which can be applied to downlink data transmission.
  • Step 203 The base station rotates the constellation diagram of each UE according to the constellation rotation angle of each UE.
  • the constellation of each UE may be rotated after the mapping of symbols to antenna arrays to be transmitted for each UE is completed.
  • the base station as the transmitting end, after determining the constellation rotation between the modulation constellations of the data streams of the plurality of UEs, superimposing the signals (ie, the data streams) rotated by the respective UEs through the constellation, and simultaneously transmitting them to Users in the small area.
  • each stream uses an independent modulation method.
  • the receiving end is a user in the system (usually a cell center user).
  • the constellation of the UE may be rotated by a variety of methods as follows.
  • MUST downlink multi-user shared transmission
  • the following two methods are proposed (in the example, the user 1 adopts an arbitrary modulation mode, User 2 uses QPSK modulation).
  • the signal components on the antennas can be adjusted by the following formula (6), thereby achieving a rotation angle of The constellation diagram rotates.
  • the signal components on the antennas can be adjusted by the following formula (7), thereby achieving a rotation angle of The constellation diagram rotates.
  • ⁇ 0 , ⁇ 1 ⁇ ⁇ 0, 1 ⁇ are determined by the modulation symbol of the user 2 and the modulation mode (in this example, the QPSK modulation mode); d is the amplitude factor of the user 1 modulation symbol; I, Q are used by the user The modulation symbol of 1 is determined; c represents the amplitude factor of the user 2 modulation symbol.
  • the signal x can be transmitted to each UE, thereby implementing downlink data transmission.
  • the constellation of one of the plurality of UEs is not rotated, and only the constellation diagrams of the remaining UEs may be rotated.
  • the constellation diagram of the UE that does not perform the constellation rotation can be recognized as the reference system, and the constellation rotation angles of the remaining UEs are the relative angles of rotation with respect to the reference frame.
  • the constellation of one of the UEs may be used as a frame of reference to determine only the rotation angle of the constellation of the other UE relative to the frame of reference.
  • Figure 3 shows the processing of the base station while processing the downstream data stream.
  • the base station processes two downlink data streams, wherein the data stream Stream 1 transmitted to the UE1 will perform constellation rotation, and the data stream Stream 2 transmitted to the UE2 will not perform constellation rotation.
  • the rotation angle of the UE1 constellation is obtained according to the method shown in the above steps 201-203. Its constellation is rotated as described in step 204.
  • the signal transmitted by the transmitter of the base station will be a mixed signal of the signal rotated by the UE1 through the constellation and the signal that the UE2 has not rotated through the constellation.
  • the multi-user sharing module is used to perform multiplexing of multi-user data, and may specifically include: a NOMA module, a multi-user shared access (MUSA) encoding module, and a low-density signature-orthogonal frequency division multiplexing (LDS-OFDM) encoding. Module or IGMA encoding module and so on.
  • an example of the present application also proposes a constellation rotation method.
  • the method can be applied to upper data transmission and can be performed by a base station.
  • Figure 4 shows the constellation rotation method for upstream data transmission. As shown in FIG. 4, the method includes:
  • Step 401 The base station determines a statistical feature of the received signal according to channel coefficients, noise information, and/or interference information of one or more UEs.
  • step 401 For the implementation method of the foregoing step 401, reference may be made to the implementation method of step 201, and therefore, the description is not repeated here.
  • Step 402 Determine a constellation rotation angle of each corresponding UE according to the statistical characteristics of the received signal.
  • step 402 For the implementation method of the foregoing step 402, reference may be made to the implementation method of step 202, and therefore, the description is not repeated here.
  • the constellation rotation angle of each UE can be determined separately by the operations of the above steps 401 and 402. That is, the above steps 401 and 402 provide a method for determining the rotation angle of the constellation, which can be applied to uplink data transmission.
  • Step 403 The base station notifies each UE of the constellation rotation angle of each UE.
  • the constellation rotation angle of a certain UE may be notified to the UE by various methods as follows.
  • the base station may first quantize the rotation angle of the constellation of a certain UE, and send the quantized rotation angle of the constellation to the UE by using downlink signaling.
  • the quantized result of the constellation rotation angle may be represented by a bitmap.
  • the base station may not quantize the rotation angle of the constellation of the UE, and directly transmit the angle value in the downlink signaling to the UE.
  • the above-described constellation rotation angle can be transmitted by using a differential signal.
  • the base station continuously transmits two modulation symbols, and the angular difference between the two modulation symbols can be used as the above-mentioned constellation rotation angle.
  • the foregoing downlink signaling may be dynamic signaling, which may be implemented by using the newly defined constellation rotation configuration signaling, or by using existing signaling.
  • Figure 5 shows an example of a downlink signaling.
  • the downlink signaling may be integrated with the scheduling signaling of the UE, that is, a constellation rotation indication field is added to the existing scheduling signaling, and the constellation rotation indication field may include an indication bit. For indicating that the UE performs constellation rotation, for example, when the indication bit is “0”, it indicates that the constellation rotation is not performed; and when the indication bit is “1”, it indicates that the constellation rotation is not performed.
  • the constellation rotation indication field may further include a rotation angle indication field of length K bits for carrying the quantized or unquantized constellation rotation angle.
  • the base station may first configure the reference constellation rotation angle of the UE by using quasi-static downlink signaling, and then notify the UE of the current angular offset of the rotation angle with respect to the reference constellation through dynamic downlink signaling, thereby Dynamically adjust the constellation rotation angle of the UE.
  • the base station can also notify the above-mentioned angular offset by the downlink signaling shown in FIG. At this time, a rotation angle indication field of length K bits will be used to carry the quantized angular offset.
  • the base station may predefine a codebook corresponding to a different constellation rotation angle, and configure the foregoing predefined codebook to the UE.
  • the base station can notify the UE by dynamic downlink signaling by using the codebook index corresponding to the current rotation angle of the constellation.
  • the base station can also notify the codebook index corresponding to the current constellation rotation angle by the signaling shown in FIG. At this time, a rotation angle indication field of length K bits will be used to carry the codebook index.
  • the codebook may be a newly defined separate codebook corresponding to the rotation angle of the constellation.
  • a codebook may be jointly designed for the precoding and the constellation rotation angle, that is, the precoding corresponding to the UE may be determined by using a codebook index, and the constellation rotation angle corresponding to the UE may also be determined.
  • the UE may perform the steps of: receiving its own constellation rotation angle from the base station; and after completing the mapping of the symbol to be transmitted to the antenna array, according to the constellation rotation angle pair The own constellation is rotated.
  • the step of receiving the self-constellation rotation angle from the base station may be implemented in the following manners.
  • the quantized constellation rotation angle carried in the downlink signaling may also be an unquantized constellation rotation angle.
  • the foregoing downlink signaling may be an extension of existing signaling or a completely new signaling.
  • the codebook index corresponding to the rotation angle of the different constellation diagrams and the codebook index corresponding to the rotation angle of the own constellation diagram determine its own constellation rotation angle.
  • the UE may complete the channel coding, modulation, and multi-user multiplexing (mapping the symbol to be transmitted to the antenna array), and then according to its own constellation rotation angle to its own constellation diagram Rotate.
  • the method for performing the constellation rotation reference may be made to the various methods described in the foregoing step 204, and the description is not repeated here.
  • Figure 6 shows a schematic diagram of the UE while processing the upstream data stream.
  • the data stream Stream 1 corresponding to UE1 will perform constellation rotation, and the data stream Stream 2 corresponding to UE2 will not perform constellation rotation.
  • the rotation angle of the UE1 constellation is obtained according to the method shown in the above steps 401-404, and the constellation thereof is obtained.
  • the figure performs the rotation as described in step 204.
  • the signal received by the receiver of the base station will be a mixed signal of the signal that UE1 has rotated through the constellation and the signal that UE2 has not rotated through the constellation.
  • the performance and throughput of the system can be optimized by solving the method of making the above-described constellation rotation angle of the received signal random variable based on the mixed Gaussian model the largest.
  • the above-mentioned mixed Gaussian model-based received signal random variable takes into account both the influence of noise and the influence of the channel coefficient of the UE. Therefore, the constellation rotation angle value obtained according to this can be applied to different signal-to-noise ratio cases and different
  • the constellation diagram can achieve high accuracy in the case of high signal-to-noise ratio or low signal-to-noise ratio. Therefore, the method is very flexible and is suitable for a wide range of signal-to-noise ratios.
  • the method does not limit the form of the constellation, and can be applied to complex constellation forms such as quadrature amplitude modulation (QAM) and the like.
  • QAM quadrature amplitude modulation
  • the above expression is a closed expression, and therefore, the solution is such that the value of the expression is maximized.
  • the computational complexity of the rotation angle of the constellation diagram is very low, and is basically independent of the rotation angle parameter of the constellation diagram. Therefore, the hardware resources required for calculation and storage of the base station are low, and the calculation delay is small, which is suitable for real-time applications.
  • the method for determining the rotation angle of the constellation is described by taking two UEs as an example, if the above method is extended to more In the general application scenario, that is, when more than two UEs multiplex the same resources, the above constellation rotation method may be extended accordingly.
  • the UE may be ranked, for example, the UE to be improved in performance as the first-level user, which is regarded as a UE that needs to perform constellation rotation in the received random variable based on the mixed Gaussian model;
  • the other UEs are regarded as the second-level users, and their mixed signals are regarded as UEs in the received random variables based on the mixed Gaussian model that do not need to perform constellation rotation.
  • the transmission performance of the first-level user can be maximized by adjusting the above-described constellation rotation angle value.
  • the constellation rotation angles of the plurality of UEs may also be determined in a stepwise manner using the hybrid Gaussian model described above. Specifically, assume that there are n UEs multiplexing the same resource, and n>2. Then, the other users except the user 1 can be regarded as one user first, and the angle of the user 1 is adjusted first according to the above method; then, the other users except the user 2 are regarded as one user, and adjusted according to the above method. User 2's angle; ...; Finally, the remaining users except user n are treated as one user, and the angle of user n is adjusted as described above. Thus, the sub-optimal rotation angle of the n user when the signal is superimposed is obtained step by step.
  • the constellation rotation angle of each UE obtained by the above method is not an optimal solution, it can be seen through simulation experiments that the constellation rotation angle of each UE obtained by the above method does not substantially increase the computational complexity. It can also greatly improve system performance.
  • the present application proposes a constellation rotation device.
  • the device may be a separate device or a functional module integrated with the base station.
  • the internal structure of the device is as shown in FIG. 7, and mainly includes: a model establishing module 701 and a constellation rotation angle determining module 702.
  • the model establishing module 701 is configured to determine a statistical feature of the received signal according to channel coefficients, noise information, and/or interference information of one or more UEs.
  • the statistical feature of the received signal may specifically refer to an entropy of a received signal random variable determined by the base station according to channel coefficients, noise information, and/or interference information of one or more UEs.
  • determining the entropy of the received signal random variable can include the steps of: determining a distribution function of the received signal random variable; and determining an entropy of the received signal random variable based on a distribution function of the received signal random variable.
  • the distribution function of the random variable of the received signal may be determined according to the number of elements in the set of constellation points and the distribution function of noise and/or interference of all possible constellation points sent by each UE after passing through the physical channel after the physical channel. .
  • the multi-user signal can be modeled as a mixed Gaussian model.
  • the distribution function of the above noise and/or interference is the signal of each UE seen by the receiving end.
  • a cyclic symmetric Gaussian distribution function whose mean is the variance of the noise variance.
  • the entropy of the random variable can be obtained based on the distribution function of the received signal random variable.
  • the entropy of the received signal random variable may be replaced with a closed lower bound expression of the entropy of the received signal random variable as shown in equation (5).
  • the statistical feature of the received signal may specifically refer to an M-th order center distance of the received signal determined by the base station according to channel coefficients, noise information, and/or interference information of one or more UEs, where , M is a natural number greater than or equal to 2.
  • the constellation rotation angle determining module 702 is configured to respectively determine a constellation rotation angle of each corresponding UE according to the determined statistical feature.
  • the angle of the constellation rotation can be determined by the above device, and is applicable to both the transmission of the downlink data and the transmission of the uplink data.
  • the foregoing base station may further include a measurement module 703, configured to obtain channel coefficients of each UE by channel measurement, thereby determining a constellation rotation angle.
  • the constellation rotation device may further include: a constellation rotation module 704, configured to rotate the constellation of each UE according to the constellation rotation angle of each UE. After selecting the constellation of each UE, the transmitting module of the base station superimposes the signals transmitted by the respective UEs through the constellation to be superimposed and transmitted.
  • the constellation rotation module 704 described above may rotate the constellation of the UE by various methods as described above.
  • the apparatus may further include: a notification module 705, configured to respectively notify each UE of a constellation rotation angle of each UE.
  • the notification module 705 may notify the UE of the constellation rotation angle of a certain UE by using various methods as described above.
  • the present application proposes a constellation rotation device suitable for transmission of uplink data.
  • the device may be a functional module integrated with the UE.
  • the internal structure of the device is shown in Figure 8, which mainly includes:
  • the receiving module 801 is configured to receive a self-constellation rotation angle sent by the base station;
  • the constellation rotation module 802 is configured to perform constellation rotation according to its own constellation rotation angle.
  • the receiving module 801 can receive its own constellation rotation angle delivered by the base station in a plurality of manners.
  • the constellation rotation module 802 can also perform constellation rotation in a variety of ways. No repeated explanation is given here.
  • the present application further provides a computer readable storage medium having stored thereon computer instructions, wherein the computer instructions are executed by the processor to implement the foregoing FIG. 2 or FIG. 4 and other The steps of the method described herein.
  • each functional block may be implemented by one device that is physically and/or logically combined, or two or more devices that are physically and/or logically separated, directly and/or indirectly (eg, This is achieved by a plurality of devices as described above by a wired and/or wireless connection.
  • the radio base station, the user terminal, and the like in one embodiment of the present invention can function as a computer that performs processing of the radio communication method of the present invention.
  • FIG. 9 is a diagram showing an example of a hardware configuration of a radio base station and a user terminal according to an embodiment of the present invention.
  • the radio base station 10 and the user terminal 20 described above may be configured as a computer device that physically includes the processor 1001, the memory 1002, the memory 1003, the communication device 1004, the input device 1005, the output device 1006, the bus 1007, and the like.
  • the hardware structures of the wireless base station 10 and the user terminal 20 may include one or more of the devices shown in the figure, or may not include some of the devices.
  • the processor 1001 only illustrates one, but may be multiple processors.
  • the processing may be performed by one processor, or may be performed by one or more processors simultaneously, sequentially, or by other methods.
  • the processor 1001 can be installed by more than one chip.
  • the functions of the wireless base station 10 and the user terminal 20 are realized, for example, by reading a predetermined software (program) into hardware such as the processor 1001 and the memory 1002, thereby causing the processor 1001 to perform an operation, and the communication device
  • the communication performed by 1004 is controlled, and the reading and/or writing of data in the memory 1002 and the memory 1003 is controlled.
  • the processor 1001 causes the operating system to operate to control the entire computer.
  • the processor 1001 may be configured by a central processing unit (CPU) including an interface with a peripheral device, a control device, an arithmetic device, a register, and the like.
  • CPU central processing unit
  • the baseband signal processing unit 104 (204), the call processing unit 105, and the like described above may be implemented by the processor 1001.
  • the processor 1001 reads out programs (program codes), software modules, data, and the like from the memory 1003 and/or the communication device 1004 to the memory 1002, and executes various processes in accordance therewith.
  • programs program codes
  • the program a program for causing a computer to execute at least a part of the operations described in the above embodiments can be employed.
  • the control unit 401 of the user terminal 20 can be implemented by a control program stored in the memory 1002 and operated by the processor 1001, and can be similarly implemented for other functional blocks.
  • the memory 1002 is a computer readable recording medium, and may be, for example, a read only memory (ROM, Read Only Memory), a programmable read only memory (EPROM), an electrically programmable read only memory (EEPROM), or a random access memory ( At least one of RAM, Random Access Memory, and other suitable storage media.
  • the memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), or the like.
  • the memory 1002 can store an executable program (program code), a software module, and the like for implementing the wireless communication method according to the embodiment of the present invention.
  • the memory 1003 is a computer readable recording medium, and may be, for example, a flexible disk, a soft (registered trademark) disk (floppy disk), a magneto-optical disk (for example, a CD-ROM (Compact DiscROM), etc.), digital universal CD, Blu-ray (registered trademark) disc, removable disk, hard drive, smart card, flash device (eg card, stick, key driver), magnetic stripe, database, server And at least one of other suitable storage media.
  • the memory 1003 may also be referred to as an auxiliary storage device.
  • the communication device 1004 is hardware (transmission and reception device) for performing communication between computers through a wired and/or wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, and the like, for example.
  • the communication device 1004 may include a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to implement, for example, Frequency Division Duplex (FDD) and/or Time Division Duplex (TDD).
  • FDD Frequency Division Duplex
  • TDD Time Division Duplex
  • the above-described transmitting and receiving antenna 101 (201), the amplifying unit 102 (202), the transmitting and receiving unit 103 (203), the transmission path interface 106, and the like can be realized by the communication device 1004.
  • the input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside.
  • the output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that performs an output to the outside.
  • the input device 1005 and the output device 1006 may also be an integrated structure (for example, a touch panel).
  • each device such as the processor 1001 and the memory 1002 is connected via a bus 1007 for communicating information.
  • the bus 1007 may be composed of a single bus or a different bus between devices.
  • the wireless base station 10 and the user terminal 20 may include a microprocessor, a digital signal processor (DSP, Digital Signal Processor), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array ( Hardware such as FPGA, FieldProgrammableGateArray), etc., can realize some or all of each functional block through the hardware.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • PLD programmable logic device
  • Hardware such as FPGA, FieldProgrammableGateArray
  • the processor 1001 can be installed by at least one of these hardwares.
  • the channel and/or symbol can also be a signal (signaling).
  • the signal can also be a message.
  • the reference signal may also be simply referred to as RS (Reference Signal), and may also be referred to as a pilot (Pilot), a pilot signal, or the like according to applicable standards.
  • a component carrier CC, Component Carrier
  • CC Component Carrier
  • the radio frame may be composed of one or more periods (frames) in the time domain.
  • Each of the one or more periods (frames) constituting the radio frame may also be referred to as a subframe.
  • a subframe may be composed of one or more time slots in the time domain.
  • the subframe may be a fixed length of time (eg, 1 ms) that is independent of the numerology.
  • the time slot may be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA, Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain.
  • the time slot can also be a time unit based on parameter configuration.
  • the time slot may also include a plurality of minislots. Each minislot may be composed of one or more symbols in the time domain.
  • a minislot can also be referred to as a subslot.
  • Radio frames, subframes, time slots, mini-slots, and symbols all represent time units when signals are transmitted. Radio frames, subframes, time slots, mini-slots, and symbols can also use other names that correspond to each other.
  • one subframe may be referred to as a transmission time interval (TTI, TransmissionTimeInterval), and multiple consecutive subframes may also be referred to as a TTI, and one slot or one minislot may also be referred to as a TTI.
  • the subframe and/or the TTI may be a subframe (1 ms) in the existing LTE, or may be a period shorter than 1 ms (for example, 1 to 13 symbols), or may be a period longer than 1 ms.
  • a unit indicating a TTI may also be referred to as a slot, a minislot, or the like instead of a subframe.
  • TTI refers to, for example, a minimum time unit scheduled in wireless communication.
  • the radio base station performs scheduling for all user terminals to allocate radio resources (bandwidth, transmission power, etc. usable in each user terminal) in units of TTIs.
  • the definition of TTI is not limited to this.
  • the TTI may be a channel-coded data packet (transport block), a code block, and/or a codeword transmission time unit, or may be a processing unit such as scheduling, link adaptation, or the like.
  • the time interval e.g., the number of symbols
  • actually mapped to the transport block, code block, and/or codeword may also be shorter than the TTI.
  • TTI time slot or one mini time slot
  • more than one TTI ie, more than one time slot or more than one micro time slot
  • the number of slots (the number of microslots) constituting the minimum time unit of the scheduling can be controlled.
  • a TTI having a length of 1 ms may also be referred to as a regular TTI (TTI in LTE Rel. 8-12), a standard TTI, a long TTI, a regular subframe, a standard subframe, or a long subframe.
  • TTI shorter than a conventional TTI may also be referred to as a compressed TTI, a short TTI, a partial TTI (partial or fractional TTI), a compressed subframe, a short subframe, a minislot, or a subslot.
  • a long TTI (eg, a regular TTI, a subframe, etc.) may be replaced with a TTI having a time length exceeding 1 ms
  • a short TTI eg, a compressed TTI, etc.
  • TTI length of the TTI may be replaced with 1 ms.
  • a resource block is a resource allocation unit of a time domain and a frequency domain, and may include one or more consecutive subcarriers (subcarriers) in the frequency domain.
  • the RB may include one or more symbols in the time domain, and may also be one slot, one minislot, one subframe, or one TTI.
  • a TTI and a subframe may each be composed of one or more resource blocks.
  • one or more RBs may also be referred to as a physical resource block (PRB, Physical RB), a sub-carrier group (SCG), a resource element group (REG, a resource element group), a PRG pair, an RB pair, and the like.
  • a resource block may also be composed of one or more resource elements (RE, ResourceElement).
  • RE resource elements
  • ResourceElement For example, one RE can be a subcarrier and a symbol of a radio resource area.
  • radio frames, subframes, time slots, mini-slots, symbols, and the like are merely examples.
  • the number of subframes included in the radio frame, the number of slots of each subframe or radio frame, the number of microslots included in the slot, the number of symbols and RBs included in the slot or minislot, and the number of RBs included in the RB The number of subcarriers, the number of symbols in the TTI, the symbol length, and the length of the cyclic prefix (CP, Cyclic Prefix) can be variously changed.
  • the information, parameters, and the like described in the present specification may be expressed by absolute values, may be represented by relative values with predetermined values, or may be represented by other corresponding information.
  • wireless resources can be indicated by a specified index.
  • the formula or the like using these parameters may be different from those explicitly disclosed in the present specification.
  • the information, signals, and the like described in this specification can be expressed using any of a variety of different techniques.
  • data, commands, instructions, information, signals, bits, symbols, chips, etc. which may be mentioned in all of the above description, may pass voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of them. Combined to represent.
  • information, signals, and the like may be output from the upper layer to the lower layer, and/or from the lower layer to the upper layer.
  • Information, signals, etc. can be input or output via a plurality of network nodes.
  • Information or signals input or output can be stored in a specific place (such as memory) or managed by a management table. Information or signals input or output may be overwritten, updated or supplemented. The output information, signals, etc. can be deleted. The input information, signals, etc. can be sent to other devices.
  • the notification of the information is not limited to the mode/embodiment described in the specification, and may be performed by other methods.
  • the notification of the information may be through physical layer signaling (eg, Downlink Control Information (DCI), uplink control information (UCI, Uplink Control Information), upper layer signaling (eg, radio resource control (RRC, RadioResourceControl). Signaling, broadcast information (MIB (Master Information Block), System Information Block (SIB, System Information Block), etc.), Media Access Control (MAC, Medium Access Control) signaling, other signals, or a combination thereof.
  • DCI Downlink Control Information
  • UCI uplink control information
  • RRC RadioResourceControl
  • Signaling broadcast information (MIB (Master Information Block), System Information Block (SIB, System Information Block), etc.
  • MIB Master Information Block
  • SIB System Information Block
  • MAC Medium Access Control
  • the physical layer signaling may be referred to as L1/L2 (Layer 1/Layer 2) control information (L1/L2 control signal), L1 control information (L1 control signal), and the like.
  • the RRC signaling may also be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.
  • the MAC signaling can be notified, for example, by a MAC Control Unit (MAC CE).
  • MAC CE MAC Control Unit
  • the notification of the predetermined information is not limited to being explicitly performed, and may be performed implicitly (for example, by not notifying the predetermined information or by notifying the other information).
  • the determination can be performed by a value (0 or 1) represented by 1 bit, or by a true or false value (boolean value) represented by true (true) or false (false), and can also be compared by numerical values ( For example, comparison with a predetermined value).
  • Software whether referred to as software, firmware, middleware, microcode, hardware description language, or other names, should be interpreted broadly to mean commands, command sets, code, code segments, program code, programs, sub- Programs, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, steps, functions, and the like.
  • software, commands, information, and the like may be transmitted or received via a transmission medium.
  • a transmission medium For example, when using wired technology (coax, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and/or wireless technology (infrared, microwave, etc.) to send software from a website, server, or other remote source
  • wired technology coax, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.
  • wireless technology infrared, microwave, etc.
  • base station (BS, BaseStation)
  • radio base station eNB
  • gNB gNodeB
  • cell a cell group
  • carrier a component carrier
  • the terms are used interchangeably.
  • the base station is sometimes referred to by a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmission point, a reception point, a femto cell, a small cell, and the like.
  • a base station can accommodate one or more (eg, three) cells (also referred to as sectors). When the base station accommodates multiple cells, the entire coverage area of the base station can be divided into a plurality of smaller areas, and each smaller area can also pass through the base station subsystem (for example, a small indoor base station (RFH, remote head (RRH), RemoteRadioHead))) to provide communication services.
  • the term "cell” or “sector” refers to a portion or the entirety of the coverage area of a base station and/or base station subsystem that performs communication services in the coverage.
  • the base station is sometimes referred to by a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmission point, a reception point, a femto cell, a small cell, and the like.
  • Mobile stations are also sometimes used by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless Terminals, remote terminals, handsets, user agents, mobile clients, clients, or several other appropriate terms are used.
  • the wireless base station in this specification can also be replaced with a user terminal.
  • each mode/embodiment of the present invention can be applied to a configuration in which communication between a radio base station and a user terminal is replaced with communication between a plurality of user-to-device (D2D) devices.
  • D2D user-to-device
  • the function of the above-described wireless base station 10 can be regarded as a function of the user terminal 20.
  • words such as "upstream” and "downstream” can also be replaced with "side”.
  • the uplink channel can also be replaced with a side channel.
  • the user terminal in this specification can also be replaced with a wireless base station.
  • the function of the user terminal 20 described above can be regarded as a function of the wireless base station 10.
  • a specific operation performed by a base station is also performed by an upper node (upper node) depending on the situation.
  • various actions performed for communication with the terminal may pass through the base station and one or more network nodes other than the base station.
  • MME Mobility Management Entity
  • S-GW Serving-Gateway
  • S-GW Serving-Gateway
  • LTE Long Term Evolution
  • LTE-A Advanced Long Term Evolution
  • LTE-B Long-Term Evolution
  • LTE-Beyond Long-Term Evolution
  • Super 3rd generation mobile communication system SUPER 3G
  • IMT-Advanced advanced international mobile communication
  • 4th generation mobile communication system (4G, 4th generation mobile communication system
  • 5G 5th generation mobile communication system
  • future radio access FAA
  • new radio access technology New-RAT, Radio Access Technology
  • NR New Radio Access Technology
  • NX new radio access
  • FX Next Generation Wireless Access
  • GSM Registered trademark
  • GSM Global System for Mobile Communications
  • CDMA2000 Code Division Multiple Access 2000
  • UMB Ultra Mobile Broadband
  • IEEE 802.11 Wi-Fi (registered trademark)
  • IEEE 802.16 WiMAX (registered trademark)
  • IEEE 802.20 Ultra Wideband
  • any reference to a unit using the names "first”, “second”, etc., as used in this specification, does not fully limit the number or order of the units. These names can be used in this specification as a convenient method of distinguishing between two or more units. Thus, reference to a first element and a second element does not mean that only two elements may be employed or that the first element must prevail in the form of the second unit.
  • determination used in the present specification sometimes includes various actions. For example, regarding “judgment (determination)", calculation, calculation, processing, deriving, investigating, looking up (eg, table, database, or other) may be performed. Search in the data structure, ascertaining, etc. are considered to be “judgment (determination)”. Further, regarding “judgment (determination)”, reception (for example, receiving information), transmission (for example, transmission of information), input (input), output (output), and access (for example) may also be performed (for example, Accessing data in memory, etc. is considered to be “judgment (determination)”.
  • judgment (determination) it is also possible to consider “resolving”, “selecting”, selecting (choosing), establishing (comparing), comparing (comparing), etc. as “judging (determining)”. That is to say, regarding "judgment (determination)", several actions can be regarded as performing "judgment (determination)".
  • connection means any direct or indirect connection or combination between two or more units, This includes the case where there is one or more intermediate units between two units that are “connected” or “coupled” to each other.
  • the combination or connection between the units may be physical, logical, or a combination of the two.
  • connection can also be replaced with "access”.
  • two units may be considered to be electrically connected by using one or more wires, cables, and/or printed, and as a non-limiting and non-exhaustive example by using a radio frequency region.
  • the electromagnetic energy of the wavelength of the region, the microwave region, and/or the light is "connected” or "bonded” to each other.

Abstract

本申请提供了一种星座图旋转方法，包括：根据一个或多个用户设备(UE)的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征；根据所确定的接收信号的统计特征确定各个UE的星座图旋转角度；以及在完成针对各个UE待传输的符号至天线阵的映射后，分别根据各个UE的星座图旋转角度对各个UE的星座图进行旋转。本申请还提供了星座图旋转角度确定方法以及与上述方法对应的装置。

Description

星座图旋转方法及装置
本申请要求于2017年4月27日提交中国专利局、申请号为201710286473.6，发明名称为“星座图旋转方法及装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本申请涉及移动通信技术领域，特别涉及多用户接入技术中的星座图旋转方法及装置。
发明背景
通过非正交多址接入(NOMA)技术可以显著提高小区边缘用户的上行和下行传输性能以及系统的吞吐量。而且根据信息论，通过调整用户终端(UE)的星座图旋转角度可以进一步提高NOMA系统的传输性能以及吞吐量。为此，需要研究如何确定UE的星座图旋转角度以优化NOMA系统的传输性能和吞吐率。
发明内容
本申请的实例提出了一种星座图旋转方法。该方法包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定基站的接收信号的统计特征，其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；根据所确定的接收信号的统计特征分别确定各个UE的星座图旋转角度；以及根据各个UE的星座图旋转角度对所述一个或者多个UE的星座图进行旋转。
本申请的实例还提出了一种星座图旋转方法。该方法包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定基站的 接收信号的统计特征，其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；根据所确定的接收信号的统计特征分别确定各个UE的星座图旋转角度；以及将各个UE的星座图旋转角度分别通知各个UE。
本申请的实例又提出了一种星座图旋转方法。该方法包括：从基站接收自身的星座图旋转角度，其中，所述星座图旋转角度是由基站根据接收信号的统计特征确定的，所述接收信号为所述基站通过物理信道接收到的一个或多个用户设备UE发送的信号；所述基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定所述接收信号的统计特征；以及根据所述星座图旋转角度对自身的星座图进行旋转。
相对应地，本申请的实例提出了一种基站。该基站包括：
处理器；
与所述处理器相连接的存储器；所述存储器中存储有机器可读指令模块；所述机器可读指令模块包括：
模型建立模块，用于根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定基站的接收信号的统计特征，其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；以及
星座图旋转角度确定模块，用于根据所确定的接收信号的统计特征分别确定各个对应UE的星座图旋转角度。
除此之外，本申请的实例还提出了一种计算机可读存储介质，其上存储有计算机指令，其中，所述计算机指令被处理器执行时实现上述任一方法的步骤。
附图简要说明
为了更清楚地说明本发明实施例或现有技术中的技术方案，下面将 对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本发明的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动性的前提下，还可以根据这些附图获得其他的附图。
图1显示了本申请实例所述的无线通信系统的接入网侧一个示例；
图2显示了本申请实例所述的适用于下行数据传输的星座图旋转方法；
图3显示了本申请实例所述的基站在处理下行数据流时的处理过程；
图4显示了本申请实例所述的适用于上行数据传输的星座图旋转方法；
图5显示了一个下行信令的示例；
图6显示了本申请实例所述的UE在处理上行数据流时的处理过程；
图7显示了本申请一实例所述的星座图旋转装置结构示意图；
图8显示了本申请一实例所述的星座图旋转装置结构示意图；以及
图9是本申请一实例所涉及的无线基站和用户终端的硬件结构示意图。
具体实施方式
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
为了描述上的简洁和直观，下文通过描述若干代表性的实施例来对本发明的方案进行阐述。实施例中大量的细节仅用于帮助理解本发明的 方案。但是很明显，本发明的技术方案实现时可以不局限于这些细节。为了避免不必要地模糊了本发明的方案，一些实施方式没有进行细致地描述，而是仅给出了框架。下文中，“包括”是指“包括但不限于”，“根据……”是指“至少根据……，但不限于仅根据……”。下文中没有特别指出一个成分的数量时，意味着该成分可以是一个也可以是多个，或可理解为至少一个。
如前所述，通过调整UE的星座图旋转角度可以进一步提高NOMA系统的传输性能以及吞吐量。而对于如何确定UE的星座图旋转角度以最大化系统的吞吐量却是非常复杂的问题。目前，可以通过穷举的方法遍历所有可能的星座图旋转角度，并从中找出使得系统性能最佳的星座图旋转角度。但是，可以想象，这样的处理方式计算复杂度非常高，基站需要大量的硬件资源以进行计算以及存储，而且灵活度也非常差，并不适用于实时业务的应用。此外，除了上述方法之外，还可以遍历所有可能的星座图旋转角度(或采用优化理论中常用的最大最小优化方法)，从中找到使得接收端的总和星座图(或复合星座图或叠加星座图，composite constellation)中距离最近的两个星座点之间的距离的最大化的星座图旋转角度。本领域的技术人员可以理解，这样的做法虽然在一定程度内降低了计算的复杂度，但是，这种方法并没有考虑到噪声的影响，因此，在信噪比较低的情况下所确定的星座图旋转角度并不是最佳的星座图旋转角度，也即在信噪比较低的情况下，采用这种方法无法很好的优化系统性能以及吞吐量。
基于上述说明，本申请的实例提出了一种星座图旋转方法，可以用以确定上、下行各个UE星座图旋转的角度。而且本申请实例提出的方法既考虑了UE的信道系数等小尺度信道信息，还考虑了UE的信噪比等大尺度信道信息，因此，所确定的UE的星座图旋转角度在各种信噪 比条件下都可以获得很好的系统性能和吞吐量，而且该方法的计算复杂度非常小，从而可以降低基站的计算量，减小计算时延以及基站的功率消耗，同时也可以降低基站在计算以及存储方面对于硬件资源的要求。
图1显示了本申请实例所述的无线通信系统的接入网侧一个示例。从图1可以看出，本申请实例所述的无线通信系统中可以包括至少一个基站(BS)以及至少两个UE，例如UE1和UE2。其中，UE1和UE2可以通过非正交多址接入(NOMA)方式接入上述BS。由于，UE1和UE2是通过非正交方式复用相同的时频资源的，因此，可以通过对UE进行星座图旋转的方式来提高系统的传输性能以及吞吐量。在图1所示的系统中，假设UE2不进行星座图旋转，而UE1的星座图旋转角度是
Figure PCTCN2018079538-appb-000001
(相当于UE1的星座图参照UE2的星座图的旋转角度是
Figure PCTCN2018079538-appb-000002
)，则此时基站接收到的信号可以如下面公式(1)所示。
Figure PCTCN2018079538-appb-000003
其中，
Figure PCTCN2018079538-appb-000004
为基站的接收信号；x 1为UE1未进行星座图旋转时，发送的信号经过物理信道(即经过衰减和衰落)后在基站端看到的信号(该信号实际为UE1调制符号乘以信道系数)；
Figure PCTCN2018079538-appb-000005
为UE1进行星座图旋转后，发送的信号经过物理信道后在基站端看到的信号；x 2为UE2发送的信号经过物理信道后在基站端看到的信号；
Figure PCTCN2018079538-appb-000006
为UE1的星座图相对于自己的原星座图的旋转角度。
另外，可以令
Figure PCTCN2018079538-appb-000007
以及
Figure PCTCN2018079538-appb-000008
其中，
Figure PCTCN2018079538-appb-000009
代表随机变量
Figure PCTCN2018079538-appb-000010
的分布函数为
Figure PCTCN2018079538-appb-000011
分布函数
Figure PCTCN2018079538-appb-000012
由UE(们)的信道系数、UE(们)的发送星座图和UE(们)星座图的旋转角度唯一确定。
Figure PCTCN2018079538-appb-000013
代表随机变量
Figure PCTCN2018079538-appb-000014
的分布函数为
Figure PCTCN2018079538-appb-000015
其中，分布函数
Figure PCTCN2018079538-appb-000016
由UE1的信道系数，UE1的发 送星座图和UE1的旋转角度唯一确定。
Figure PCTCN2018079538-appb-000017
代表随机变量x 2的分布函数为
Figure PCTCN2018079538-appb-000018
其中分布函数
Figure PCTCN2018079538-appb-000019
由UE2的信道系数，UE2的发送星座图唯一确定。
Figure PCTCN2018079538-appb-000020
代表随机变量n 0,r满足循环对称复高斯噪声分布函数
Figure PCTCN2018079538-appb-000021
其中，
Figure PCTCN2018079538-appb-000022
为接收端信号的随机变量。
Figure PCTCN2018079538-appb-000023
为所有可能的
Figure PCTCN2018079538-appb-000024
组成的集合；X 2为所有可能的x 2组成的集合；
Figure PCTCN2018079538-appb-000025
为集合
Figure PCTCN2018079538-appb-000026
中的元素个数，|X 2|为集合X 2中的元素个数。n 0,r为噪声；
Figure PCTCN2018079538-appb-000027
为噪声方差；I t为单位对角矩阵；t为基站侧的天线数以及CN(u,v)为均值为u方差为v的循环对称复高斯分布。
如前所述，通过星座图旋转可以提高系统性能，那么，本申请实例所要解决的主要问题就是如何确定上述
Figure PCTCN2018079538-appb-000028
值，使得系统的吞吐量最大，从而达到尽可能优化系统的传输性能的目的。
根据上述基站的接收信号表达方式，可以确定系统的性能以及吞吐量的优化目标等效于找到使得表达式
Figure PCTCN2018079538-appb-000029
的值最大的星座图旋转角度
Figure PCTCN2018079538-appb-000030
其中，I(A；B)代表随机变量A与B的互信息函数。
但是，本领域的技术人员可以理解，实现上述目标的计算复杂度非常高，在实际应用中很难很快计算出来，因此，需要对上述优化目标进行进一步转化。
为此，在本申请的一些实例中，提出混合高斯模型，并对上述接收端信号的随机变量进行混合高斯模型建模，得到基于混合高斯模型的接收信号随机变量
Figure PCTCN2018079538-appb-000031
可知其分布函数可如下公式(2)所示：
Figure PCTCN2018079538-appb-000032
其中，
Figure PCTCN2018079538-appb-000033
为代表接收端信号的随机变量；
Figure PCTCN2018079538-appb-000034
为UE1星座图旋转角 度
Figure PCTCN2018079538-appb-000035
后发送的信号经过物理信道后在接收端看到的信号；
Figure PCTCN2018079538-appb-000036
是UE1发送的所有可能的星座点经过物理信道后在接收端看到的星座点集合；
Figure PCTCN2018079538-appb-000037
为UE2星座图旋转角度
Figure PCTCN2018079538-appb-000038
后发送的信号经过物理信道后在基站端看到的信号；
Figure PCTCN2018079538-appb-000039
是UE2发送的所有可能的星座点经过物理信道后在接收端看到的星座点集合；
Figure PCTCN2018079538-appb-000040
为UE N星座图旋转角度
Figure PCTCN2018079538-appb-000041
后发送的信号经过物理信道后在接收端看到的信号；
Figure PCTCN2018079538-appb-000042
是UE N发送的所有可能的星座点经过物理信道后在接收端看到的星座点集合；N为UE的个数；
Figure PCTCN2018079538-appb-000043
为集合
Figure PCTCN2018079538-appb-000044
中的元素个数，
Figure PCTCN2018079538-appb-000045
为集合
Figure PCTCN2018079538-appb-000046
中的元素个数，
Figure PCTCN2018079538-appb-000047
为集合
Figure PCTCN2018079538-appb-000048
中的元素个数；
Figure PCTCN2018079538-appb-000049
为噪声方差；I为单位对角矩阵；以及CN(u,v)为均值为u方差为v的循环对称复高斯分布。
例如，当UE的个数是2个时，上述基于混合高斯模型的接收信号随机变量的分布函数可如下公式(3)所示：
Figure PCTCN2018079538-appb-000050
又例如，当UE的个数是3个时，上述基于混合高斯模型的接收信号随机变量的分布函数可如下公式(4)所示：
Figure PCTCN2018079538-appb-000051
可以看出，通过上述混合高斯模型得到的接收信号的随机变量
Figure PCTCN2018079538-appb-000052
的分布函数既与UE的信道系数等小尺度信道信息(
Figure PCTCN2018079538-appb-000053
和x 2,k中包含信道系数等小尺度信息)有关，也与UE的信噪比等大尺度信道信息(高斯模型的方差σ 2代表UE信道的噪声)有关。而且，根据接收信号随机变量 的分布函数可以确定接收信号随机变量的熵。例如，本领域的技术人员可以理解，如果将随机变量Y的分布函数记作f(y)，则该随机变量熵为可以表示为h(Y)＝∫f(y)log(f(y))dy，其中，h(Y)代表随机遍变量Y的熵。这里，随机变量Y用大写表示，主要用以区别于积分变量y。
而且经过推理证明可以得到：当UE的个数为2个时，求解
Figure PCTCN2018079538-appb-000054
使得
Figure PCTCN2018079538-appb-000055
最大化的优化目标等效于求解
Figure PCTCN2018079538-appb-000056
使得
Figure PCTCN2018079538-appb-000057
最大化的优化目标；其中，h()是指求随机变量
Figure PCTCN2018079538-appb-000058
的熵。
因而，在本申请的实例中，在确定UE的基于混合高斯模型的接收信号随机变量的分布函数之后，可根据其分布函数求解使得该接收信号随机变量的熵最大的星座图旋转角度，并将其作为该UE星座图旋转角度。
如前所述，当UE的个数为2个时，求解
Figure PCTCN2018079538-appb-000059
使得
Figure PCTCN2018079538-appb-000060
最大化等效于求解
Figure PCTCN2018079538-appb-000061
使得
Figure PCTCN2018079538-appb-000062
最大化，因此，通过上述方法得到的星座图旋转角度亦可以使得
Figure PCTCN2018079538-appb-000063
最大化，也即使得系统吞吐量最大。而当UE的个数超过2个时，求解
Figure PCTCN2018079538-appb-000064
使得
Figure PCTCN2018079538-appb-000065
最大化也可以在很大程度上提高系统的吞吐量。也就是说，通过最大化上述基于混合高斯模型的接收信号随机变量可以优化系统的性能以及吞吐量。而且，上述基于混合高斯模型的接收信号随机变量既考虑了噪声的影响以及不同星座点的幅度，也即既考虑了噪声的情况以及UE的信道系数，因而，据此得到的
Figure PCTCN2018079538-appb-000066
值可以适用不同的信噪比情况以及不同的星座图，在信噪比较高或信噪比较低的情况下都可以获得很高的准确度，因此，该方法的灵活度非常高，适用非常广的信噪比范围。而且，该方法并不限制星座图的形式，可以适用于各种复杂的星座图形式，例如正交幅度调制(QAM)等等。
更进一步，为了进一步降低在求解
Figure PCTCN2018079538-appb-000067
使得
Figure PCTCN2018079538-appb-000068
最大化的数值计算过程中的计算复杂度，则可以对上述
Figure PCTCN2018079538-appb-000069
进行近似处理，得到其闭式下限 表达式
Figure PCTCN2018079538-appb-000070
来代替上述
Figure PCTCN2018079538-appb-000071
也即将使得
Figure PCTCN2018079538-appb-000072
最大化的星座图旋转角度
Figure PCTCN2018079538-appb-000073
作为对应UE的星座图旋转角度。此时，优化目标进一步转化为求解
Figure PCTCN2018079538-appb-000074
使得
Figure PCTCN2018079538-appb-000075
最大化。
在本申请的一些实例中，当UE的个数为2个时，上述
Figure PCTCN2018079538-appb-000076
的闭式下限表达式
Figure PCTCN2018079538-appb-000077
可以如下公式(5)所示：
Figure PCTCN2018079538-appb-000078
其中，C为一个常数；
Figure PCTCN2018079538-appb-000079
代表两个星座点之间的距离。具体地，
Figure PCTCN2018079538-appb-000080
代表
Figure PCTCN2018079538-appb-000081
代表
Figure PCTCN2018079538-appb-000082
X代表
Figure PCTCN2018079538-appb-000083
X JK代表
Figure PCTCN2018079538-appb-000084
X LM代表
Figure PCTCN2018079538-appb-000085
t代表天线数；σ 2代表噪声。
从上述公式(5)可以看出，上述基于混合高斯模型的接收信号随机变量的熵的下限表达式是一个闭式表达式，又可称为闭式下限表达式，因此，求解使得其最大化的
Figure PCTCN2018079538-appb-000086
值的计算复杂度非常低，只有O(1)，也即和星座图的旋转角度参数基本无关，因此，对基站计算以及存储的硬件资源要求都很低，计算时延也很小，更适用于实时应用。
基于以上研究，可以进一步将上述思想的应用环境扩大到噪声和/或干扰是非高斯的情况下，也即将混合高斯模型扩展到非高斯的环境下，亦可称为混合模型。此时，可以用噪声和/或干扰的分布函数
Figure PCTCN2018079538-appb-000087
代替上述公式(2)、(3)或(4)中的
Figure PCTCN2018079538-appb-000088
从而得到下面的公式(6)作为非高斯环境下 接收信号随机变量的分布函数，可据此计算接收信号随机变量的熵：
Figure PCTCN2018079538-appb-000089
其中，各个参数的含义可以参考公式(2)的说明。
更进一步，还可以用接收信号的M阶中心距，例如2阶中心距(也即方差)，来代替上文中的接收信号随机变量的熵。其中，M为大于或者等于2的自然数。在这种情况下，接收信号的M阶中心距可以作为接收信号随机变量的熵的一种次优近似。此时，在确定各个UE的星座图旋转角度时，可以求解使得接收信号的M阶中心距最大时的各个UE星座图旋转角度作为各个UE的星座图旋转角度。
基于上述说明，本申请提出了一种星座图旋转方法。该方法可以适用于下行数据传输，可以由基站执行。图2显示了适用于下行数据传输的星座图旋转方法。如图2所示，该方法包括：
步骤201：基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征。
在本申请的一些实例中，上述接收信号的统计特征可以具体是指基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定的接收信号随机变量的熵。特别地，对于多用户共享传输的具体场景而言，多用户的信号可以建模为混合高斯模型，此时，上述接收信号的统计特征可以具体是指基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息并基于混合高斯/非高斯模型确定的接收信号随机变量的熵。
在本申请的一些实例中，基站可以通过信道测量分别获取多个UE的信道系数。而对于信道噪声，在本申请的一些实例中，可以采用固定的信道噪声或者根据当前系统或信道的情况设定，例如设置为-110dBm。
在本申请的一些实例中，确定接收信号随机变量的熵可以包括如下两个步骤：确定接收信号随机变量的分布函数；以及根据所述接收信号随机变量的分布函数确定所述接收信号随机变量的熵。
上述接收信号随机变量是基站侧看到的接收信号随机变量的一个变形，其分布函数具体可以参考上述公式(2)、(3)、(4)或(6)，也即根据各个UE发送的所有可能的星座点经过物理信道后在接收端看到的星座点集合中元素的个数以及噪声和/或干扰的分布函数确定所述接收信号随机变量的分布函数。而且，该接收信号随机变量的分布函数与UE的小尺度信道信息(例如信道系数)以及大尺度信道信息(例如信噪比的统计值)相关联。其中，在高斯环境下，噪声和/或干扰的分布函数为以接收端看到的各个UE的信号之和为均值以噪声方差为方差的循环对称高斯分布函数。从前面的描述可以看出，通过上述分布函数，可以得到基于混合高斯模型的接收信号随机变量的熵。
在本申请的另一些实例中，为了进一步降低计算量，可以对所述接收信号随机变量的熵的表达式进行近似处理，得到所述接收信号随机变量的熵的闭式下限表达式，用接收信号随机变量的熵的闭式下限表达式作为接收信号随机变量的熵。具体而言，上述闭式下限表达式可以如上述公式(5)所示。
此外，在本申请的另一些实例中，上述接收信号的统计特征可以具体是指基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定的接收信号的M阶中心距，其中，M为大于或等于2的自然数。
步骤202：基站根据上述接收信号的统计特征分别确定各个UE的星座图旋转角度。
如前所述，上述接收信号的随机变量是基站侧看到的接收信号随机变量的一个变形，通过推理可以证明当该接收信号随机变量的熵最大时， 系统的吞吐量可以达到最大或者近似最大。
因此，在本申请的一些实例中，可以将接收信号随机变量的熵作为上述统计特征，并求解使得接收信号随机变量的熵最大时的星座图旋转角度，并将其作为各个对应UE的星座图旋转角度。
此外，在本申请的另一些实例中，可以将接收信号的M阶中心距作为接收信号随机变量的熵的次优近似，也即可以将接收信号的M阶中心距作为上述统计特征，并求解使得接收信号M阶中心距最大时的星座图旋转角度，并将其作为各个对应UE的星座图旋转角度。
通过上述步骤201和步骤202的操作即可分别确定各个UE的星座图旋转角度。也即，上述步骤201和步骤202给出了一种星座图旋转角度确定方法，该方法可以应用于下行数据传输。
步骤203：基站分别根据各个UE的星座图旋转角度对各个UE的星座图进行旋转。
在本申请的一些实例中，可以在完成针对各个UE待传输的符号至天线阵的映射后对各个UE的星座图进行旋转。此时，基站作为发射端，在确定多个UE的数据流的调制星座图之间的星座旋转后，将各个UE经过星座图旋转后的信号(也即数据流)叠加在一起，同时发送至小区内的用户。其中，每个流采用独立的调制方式。接收端为系统中的某一个用户(通常为小区中心用户)。
在一些实例中，可以通过下面的多种方法对UE的星座图进行旋转。在下行NOMA系统中，具体针对R-14中的下行多用户共享传输(MUST)技术的基础上，以两用户场景为例，提出下面两种方法(在例子中假定用户1采用任意调制方式，用户2采用QPSK调制)。
方法1：
在基站端，两用户的待传输的符号映射至天线阵后，可以通过如下 的公式(6)调整各天线上的信号分量，从而实现旋转角度为
Figure PCTCN2018079538-appb-000090
的星座图旋转。
Figure PCTCN2018079538-appb-000091
其中，
Figure PCTCN2018079538-appb-000092
由用户2的调制符号和调制模式(在本例中为QPSK调制模式)决定；d是用户1调制符号的幅度因子；I、Q由用户1的调制符号决定；c代表用户2调制符号的幅度因子。
方法2：
在基站端，两用户的待传输的符号映射至天线阵后，可以通过如下的公式(7)调整各天线上的信号分量，从而实现旋转角度为
Figure PCTCN2018079538-appb-000093
的星座图旋转。
Figure PCTCN2018079538-appb-000094
其中，φ 0,φ 1∈{0,1}，由用户2的调制符号和调制模式(在本例中为QPSK调制模式)决定；d是用户1调制符号的幅度因子；I、Q由用户1的调制符号决定；c代表用户2调制符号的幅度因子。
在经过上述多种方法对每个天线上进行星座图旋转之后，即可将信号x发送至各个UE，从而实现下行数据传输。
为了降低计算的复杂度，可以确定上述多个UE中有一个UE的星座图是不用进行旋转的，仅将其余UE的星座图进行旋转即可。这时，可以认不进行星座图旋转的UE的星座图作为参照系，其余UE的星座图旋转角度是相对于该参照系进行旋转的相对角度。特别地，如果基站只调度了2个UE，则可以以其中一个UE的星座图作为参照系，只确定另一个UE的星座图相对于该参照系的旋转角度。
图3显示了基站在处理下行数据流时的处理过程。在图3中，基站处理了2个下行数据流，其中，发送给UE1数据流Stream 1将进行星座图旋转，而发送给UE2的数据流Stream 2将不进行星座图旋转。从图3可以看出，发送给UE的数据流在经过信道编码、调制以及多用户共享模块的复用处理之后，根据通过上述步骤201-203所示的方法得到UE1星座图的旋转角度，对其星座图进行如步骤204所述的旋转。从而，基站的发射机发送的信号将是UE1经过星座图旋转后的信号以及UE2没有经过星座图旋转的信号的混合信号。上述多用户共享模块用于进行多用户数据的复用，例如具体可以包括：NOMA模块、多用户共享接入(MUSA)编码模块、低密度签名-正交频分复用(LDS-OFDM)编码模块或IGMA编码模块等等。
此外，本申请的实例还提出了一种星座图旋转方法。该方法可以适用于上数据传输，可以由基站执行。图4显示了适用于上行数据传输的星座图旋转方法。如图4所示，该方法包括：
步骤401：基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征。
上述步骤401的实现方法可以参考步骤201的实现方法，因此，此处就不再重复说明了。
步骤402：根据上述接收信号的统计特征分别确定各个对应UE的星座图旋转角度。
上述步骤402的实现方法可以参考步骤202的实现方法，因此，此处就不再重复说明了。
而且，通过上述步骤401和步骤402的操作即可分别确定各个UE的星座图旋转角度。也即，上述步骤401和步骤402给出了一种星座图旋转角度确定方法，该方法可以应用于上行数据传输。
步骤403：基站将各个UE的星座图旋转角度分别通知各个UE。
在本申请的一些实例中，可以通过下面的多种方法将某个UE的星座图旋转角度通知给该UE。
方法1：显式通知方式
在该方法中，基站可以先对某个UE的星座图旋转角度进行量化，并将量化后的星座图旋转角度通过下行信令发送给UE。例如，在本申请的一些实例中，可以通过位图(bitmap)的方式表示星座图旋转角度的量化结果。
当然，作为上述方法的变形，基站也可以不对UE的星座图旋转角度进行量化，直接将角度值承载在下行信令中发送给UE。例如，可以采用差分信号的方式发送上述星座图旋转角度。在本申请的一个实例中，基站连续发送两个调制符号，这两个调制符号之间的角度差即可以作为上述星座图旋转角度。
上述下行信令可以是动态信令，既可以使用新定义的星座图旋转配置信令实现，也可以利用现有信令来实现。图5显示了一个下行信令的示例。从图5可以看出，该下行信令可以和UE的调度信令集成在一起，即在现有的调度信令中增加一个星座图旋转指示字段，该星座图旋转指示字段可以包含一个指示位，用于指示UE进行星座图旋转，例如该指示位为“0”时表示不进行星座图旋转；而该指示位为“1”时表示不进行星座图旋转。上述星座图旋转指示字段还可以包括一个长度为K比特的旋转角度指示域，用于承载量化后或未经过量化的星座图旋转角度。
方法2：两级配置方式
在该方法中，基站可以先通过准静态的下行信令配置UE的参考星座图旋转角度，然后，再通过动态的下行信令通知UE当前其相对于参考星座图旋转角度的角度偏置，从而动态调整UE的星座图旋转角度。
在该方法中，基站也可以通过图5所示的下行信令通知上述角度偏置。此时，长度为K比特的旋转角度指示域将用于承载量化后的角度偏置。
方法3：基于码本的隐式配置方式
在该方法中，基站可以预先定义对应不同星座图旋转角度的码本(codebook)，并将上述预先定义的码本配置给UE。这样，基站就可以将与当前星座图旋转角度对应的码本索引通过动态的下行信令通知UE。
在该方法中，基站也可以通过图5所示的信令通知将与当前星座图旋转角度对应的码本索引。此时，长度为K比特的旋转角度指示域将用于承载码本索引。
需要说明的是，在该方法中，上述码本可以是新定义的与星座图旋转角度对应的单独的码本。或者，作为其替代方案，还可以针对预编码与星座图旋转角度联合设计一个码本，也即通过一个码本索引既可以确定UE对应的预编码，也可以确定UE对应的星座图旋转角度。
相对应地，在本申请的一些实例中，UE可以执行以下步骤：从基站接收自身的星座图旋转角度；以及在完成待传输的符号至天线阵的映射后，根据所述星座图旋转角度对自身的星座图进行旋转。
其中，上述从基站接收自身的星座图旋转角度的步骤可以通过以下多种方式来实现。
方式1：
从基站接收动态的下行信令，从上述动态的下行信令中获取自身的星座图旋转角度。如前所述，上述下行信令中承载的可以是量化后的星座图旋转角度也可以是未经量化的的星座图旋转角度。而且上述下行信令可以是现有信令的扩展也可以是全新的信令。
方式2：
从基站接收准静态的下行信令，从所述准静态的下行信令中获取参考星座图旋转角度；从基站接收动态的下行信令，从所述动态的下行信令中获取旋转角度偏置；再根据所述参考星座旋转角度以及旋转角度偏置确定自身的星座图旋转角度。
方式3：
从基站接收预先定义的对应不同星座图旋转角度的码本；以及从基站接收动态的下行信令，从所述动态的下行信令中获取自身星座图旋转角度对应的码本索引；以及根据对应不同星座图旋转角度的码本以及自身星座图旋转角度对应的码本索引确定自身的星座图旋转角度。
在接收到基站通知的星座图旋转角度之后，UE可以在完成信道编码、调制以及多用户复用(将待传输的符号映射至天线阵)后，根据自身的星座图旋转角度对自身的星座图进行旋转。具体进行星座图旋转的方法可以参考上述步骤204所述的多种方法，在此不再重复说明了。
图6显示了UE在处理上行数据流时的示意图。在图6中，UE1对应的数据流Stream 1将进行星座图旋转，而UE2对应的数据流Stream 2将不进行星座图旋转。从图6可以看出，UE的数据流在经过信道编码、调制以及多用户共享模块的复用处理之后，根据通过上述步骤401-404所示的方法得到UE1星座图的旋转角度，对其星座图进行如步骤204所述的旋转。从而，基站的接收机接收到的信号将是UE1经过星座图旋转后的信号以及UE2没有经过星座图旋转的信号的混合信号。
如前所述，通过求解使得上述基于混合高斯模型的接收信号随机变量的熵最大的星座图旋转角度的方法可以优化系统的性能以及吞吐量。而且，上述基于混合高斯模型的接收信号随机变量既考虑了噪声的影响也考虑了UE的信道系数的影响，因而，据此得到的星座图旋转角度值可以适用不同的信噪比情况以及不同的星座图，在信噪比较高或信噪比 较低的情况下都可以获得很高的准确度，因此，该方法的灵活度非常高，适用非常广的信噪比范围。而且，该方法并不限制星座图的形式，可以适用于复杂的星座图形式，例如正交幅度调制(QAM)等等。
更进一步，从上述公式(5)所示的基于混合高斯模型的接收信号随机变量的下限表达式可以看出，上述表达式是一个闭式表达式，因此，求解使得该表达式的值最大时的星座图旋转角度的计算复杂度非常低，和星座图的旋转角度参数基本无关，因此，对基站计算以及存储的硬件资源要求都很低，计算时延也很小，适用于实时应用。
从前面的详细说明可以看出，在上述星座图旋转方法的描述中特别是星座图旋转角度的确定方法中都是以两个UE进行复用为例进行说明的，如果将上述方法扩展到更一般应用场景下，也即有多于两个UE复用相同资源时，可以相应地对上述星座图旋转方法进行一些扩展。
在本申请的一些实例中，可以将UE进行分级，例如将待提高性能的UE作为第一级用户，将其视为基于混合高斯模型的接收随机变量中的需要进行星座图旋转的UE；而将其他UE作为第二级用户，将其混合信号视为基于混合高斯模型的接收随机变量中的不需要进行星座图旋转的UE。这样，通过调整上述星座图旋转角度值可以最大化第一级用户的传输性能。
在本申请的一些实例中，还可以通过分步的方式利用上述混合高斯模型确定多个UE的星座图旋转角度。具体而言，假设有n个UE复用相同资源，且n〉2。则可以先将除用户1之外的其余用户看做一个用户，并按照上述方法先调整用户1的角度；然后，再将除用户2之外的其余用户看做一个用户，并按照上述方法调整用户2的角度；……；最后，将除用户n之外的其余用户看做一个用户，并按照上述方法调整用户n的角度。从而，分步得到n用户在信号叠加时候的次优旋转角度。
通过上述方法得到的各个UE的星座图旋转角度虽然不是最优解，但是经过仿真实验可以看出，通过上述方法得到的各个UE的星座图旋转角度在基本不大量增加计算复杂度的情况下，也可以大幅度提高系统性能。
相对应地，本申请提出了一种星座图旋转装置。该装置可以是单独的装置也可以是与基站集成在一起的功能模块。该装置的内部结构如图7所示，主要包括：模型建立模块701和星座图旋转角度确定模块702。
其中，模型建立模块701用于根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征。
在本申请的一些实例中，上述接收信号的统计特征可以具体是指基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定的接收信号随机变量的熵。在一些实例中，确定接收信号随机变量的熵可以包括如下两个步骤：确定接收信号随机变量的分布函数；以及根据所述接收信号随机变量的分布函数确定所述接收信号随机变量的熵。其中，可以根据各个UE发送的所有可能的星座点经过物理信道后在接收端看到的星座点集合中元素的个数以及噪声和/或干扰的分布函数确定所述接收信号随机变量的分布函数。特别地，对于多用户共享传输的具体场景而言，多用户的信号可以建模为混合高斯模型，此时，上述噪声和/或干扰的分布函数为以接收端看到的各个UE的信号之和为均值以噪声方差为方差的循环对称高斯分布函数。基于接收信号随机变量的分布函数可以得到该随机变量的熵。
为了进一步降低计算的复杂度，在本申请的一些实例中，可以利用公式(5)所示的接收信号随机变量的熵的闭式下限表达式来代替该接收信号随机变量的熵。
此外，在本申请的另一些实例中，上述接收信号的统计特征可以具 体是指基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定的接收信号的M阶中心距，其中，M为大于或等于2的自然数。
上述星座图旋转角度确定模块702用于根据上述确定的统计特征分别确定各个对应UE的星座图旋转角度。
通过上述装置可以确定星座图旋转的角度，既适用于下行数据的传输也适用于上行数据的传输。
上述基站还可以包括测量模块703，用于通过信道测量得到各个UE的信道系数，从而确定星座图旋转角度。
为了进行下行数据的传输，上述星座图旋转装置还可以进一步包括：星座图旋转模块704，用于分别根据各个UE的星座图旋转角度对各个UE的星座图进行旋转。在将各个UE的星座图进行选择之后，基站的发射模块将各个UE经过星座图旋转后的信号叠加在一起发送。
在本申请的实例中，上述星座图旋转模块704可以通过前面所述的多种方法对UE的星座图进行旋转。
此外，为了进行上行数据的传输，该装置还可以进一步包括：通知模块705，用于将各个UE的星座图旋转角度分别通知各个UE。在本申请的一些实例中，上述通知模块705可以通过上述的多种方法将某个UE的星座图旋转角度通知给该UE。
相应地，本申请提出了一种星座图旋转装置，适用于上行数据的传输。该装置可以是与UE集成在一起的功能模块。该装置的内部结构如图8所示，主要包括：
接收模块801，用于接收基站下发的自身的星座图旋转角度；以及
星座图旋转模块802，用于根据自身的星座图旋转角度进行星座图旋转。
在本申请的一些实例中，如前所述，上述接收模块801可以使用多 种方式接收基站下发的自身的星座图旋转角度。星座图旋转模块802也可以使用多种方式来进行星座图旋转。在这里不进行重复说明了。
对应上述星座图旋转方法、基站以及UE设备，本申请还提出了计算机可读存储介质，其上存储有计算机指令，其中，所述计算机指令被处理器执行时实现上述图2或图4以及其他文中所描述方法的步骤。
需要说明的是，上述各流程和各结构图中不是所有的步骤和模块都是必须的，可以根据实际的需要忽略某些步骤或模块。各步骤的执行顺序不是固定的，可以根据需要进行调整。各模块的划分仅仅是为了便于描述采用的功能上的划分，实际实现时，一个模块可以分由多个模块实现，多个模块的功能也可以由同一个模块实现，这些模块可以位于同一个设备中，也可以位于不同的设备中。
另外，上述实施方式的说明中使用的框图示出了以功能为单位的块。这些功能块(结构单元)通过硬件和/或软件的任意组合来实现。此外，各功能块的实现手段并不特别限定。即，各功能块可以通过在物理上和/或逻辑上相结合的一个装置来实现，也可以将在物理上和/或逻辑上相分离的两个以上装置直接地和/或间接地(例如通过有线和/或无线)连接从而通过上述多个装置来实现。
例如，本发明的一实施方式中的无线基站、用户终端等可以作为执行本发明的无线通信方法的处理的计算机来发挥功能。图9是示出本发明的一实施方式所涉及的无线基站和用户终端的硬件结构的一例的图。上述的无线基站10和用户终端20可以作为在物理上包括处理器1001、内存1002、存储器1003、通信装置1004、输入装置1005、输出装置1006、总线1007等的计算机装置来构成。
另外，在以下的说明中，“装置”这样的文字也可替换为电路、设备、单元等。无线基站10和用户终端20的硬件结构可以包括一个或多个图 中所示的各装置，也可以不包括部分装置。
例如，处理器1001仅图示出一个，但也可以为多个处理器。此外，可以通过一个处理器来执行处理，也可以通过一个以上的处理器同时、依次、或采用其它方法来执行处理。另外，处理器1001可以通过一个以上的芯片来安装。
无线基站10和用户终端20中的各功能例如通过如下方式实现：通过将规定的软件(程序)读入到处理器1001、内存1002等硬件上，从而使处理器1001进行运算，对由通信装置1004进行的通信进行控制，并对内存1002和存储器1003中的数据的读出和/或写入进行控制。
处理器1001例如使操作系统进行工作从而对计算机整体进行控制。处理器1001可以由包括与周边装置的接口、控制装置、运算装置、寄存器等的中央处理器(CPU，Central Processing Unit)构成。例如，上述的基带信号处理单元104(204)、呼叫处理单元105等可以通过处理器1001实现。
此外，处理器1001将程序(程序代码)、软件模块、数据等从存储器1003和/或通信装置1004读出到内存1002，并根据它们执行各种处理。作为程序，可以采用使计算机执行在上述实施方式中说明的动作中的至少一部分的程序。例如，用户终端20的控制单元401可以通过保存在内存1002中并通过处理器1001来工作的控制程序来实现，对于其它功能块，也可以同样地来实现。内存1002是计算机可读取记录介质，例如可以由只读存储器(ROM，ReadOnlyMemory)、可编程只读存储器(EPROM，ErasableProgrammableROM)、电可编程只读存储器(EEPROM，ElectricallyEPROM)、随机存取存储器(RAM，RandomAccessMemory)、其它适当的存储介质中的至少一个来构成。内存1002也可以称为寄存器、高速缓存、主存储器(主存储装置)等。 内存1002可以保存用于实施本发明的一实施方式所涉及的无线通信方法的可执行程序(程序代码)、软件模块等。
存储器1003是计算机可读取记录介质，例如可以由软磁盘(flexible disk)、软(注册商标)盘(floppy disk)、磁光盘(例如，只读光盘(CD-ROM(CompactDiscROM)等)、数字通用光盘、蓝光(Blu-ray，注册商标)光盘)、可移动磁盘、硬盘驱动器、智能卡、闪存设备(例如，卡、棒(stick)、密钥驱动器(key driver))、磁条、数据库、服务器、其它适当的存储介质中的至少一个来构成。存储器1003也可以称为辅助存储装置。
通信装置1004是用于通过有线和/或无线网络进行计算机间的通信的硬件(发送接收设备)，例如也称为网络设备、网络控制器、网卡、通信模块等。通信装置1004为了实现例如频分双工(FDD，FrequencyDivisionDuplex)和/或时分双工(TDD，TimeDivisionDuplex)，可以包括高频开关、双工器、滤波器、频率合成器等。例如，上述的发送接收天线101(201)、放大单元102(202)、发送接收单元103(203)、传输路径接口106等可以通过通信装置1004来实现。
输入装置1005是接受来自外部的输入的输入设备(例如，键盘、鼠标、麦克风、开关、按钮、传感器等)。输出装置1006是实施向外部的输出的输出设备(例如，显示器、扬声器、发光二极管(LED，LightEmittingDiode)灯等)。另外，输入装置1005和输出装置1006也可以为一体的结构(例如触控面板)。
此外，处理器1001、内存1002等各装置通过用于对信息进行通信的总线1007连接。总线1007可以由单一的总线构成，也可以由装置间不同的总线构成。
此外，无线基站10和用户终端20可以包括微处理器、数字信号处 理器(DSP，DigitalSignalProcessor)、专用集成电路(ApplicationSpecificIntegratedCircuit，ASIC)、可编程逻辑器件(PLD，ProgrammableLogicDevice)、现场可编程门阵列(FPGA，FieldProgrammableGateArray)等硬件，可以通过该硬件来实现各功能块的部分或全部。例如，处理器1001可以通过这些硬件中的至少一个来安装。
另外，关于本说明书中说明的用语和/或对本说明书进行理解所需的用语，可以与具有相同或类似含义的用语进行互换。例如，信道和/或符号也可以为信号(信令)。此外，信号也可以为消息。参考信号也可以简称为RS(ReferenceSignal)，根据所适用的标准，也可以称为导频(Pilot)、导频信号等。此外，分量载波(CC，ComponentCarrier)也可以称为小区、频率载波、载波频率等。
此外，无线帧在时域中可以由一个或多个期间(帧)构成。构成无线帧的该一个或多个期间(帧)中的每一个也可以称为子帧。进而，子帧在时域中可以由一个或多个时隙构成。子帧可以是不依赖于参数配置(numerology)的固定的时间长度(例如1ms)。
进而，时隙在时域中可以由一个或多个符号(正交频分复用(OFDM，OrthogonalFrequencyDivisionMultiplexing)符号、单载波频分多址(SC-FDMA，SingleCarrierFrequencyDivisionMultipleAccess)符号等)构成。此外，时隙也可以是基于参数配置的时间单元。此外，时隙还可以包括多个微时隙。各微时隙在时域中可以由一个或多个符号构成。此外，微时隙也可以称为子时隙。
无线帧、子帧、时隙、微时隙以及符号均表示传输信号时的时间单元。无线帧、子帧、时隙、微时隙以及符号也可以使用各自对应的其它名称。例如，一个子帧可以被称为传输时间间隔(TTI， TransmissionTimeInterval)，多个连续的子帧也可以被称为TTI，一个时隙或一个微时隙也可以被称为TTI。也就是说，子帧和/或TTI可以是现有的LTE中的子帧(1ms)，也可以是短于1ms的期间(例如1～13个符号)，还可以是长于1ms的期间。另外，表示TTI的单元也可以称为时隙、微时隙等而非子帧。
在此，TTI例如是指无线通信中调度的最小时间单元。例如，在LTE系统中，无线基站对各用户终端进行以TTI为单位分配无线资源(在各用户终端中能够使用的频带宽度、发射功率等)的调度。另外，TTI的定义不限于此。
TTI可以是经过信道编码的数据包(传输块)、码块、和/或码字的发送时间单元，也可以是调度、链路适配等的处理单元。另外，在给出TTI时，实际上与传输块、码块、和/或码字映射的时间区间(例如符号数)也可以短于该TTI。
另外，一个时隙或一个微时隙被称为TTI时，一个以上的TTI(即一个以上的时隙或一个以上的微时隙)也可以成为调度的最小时间单元。此外，构成该调度的最小时间单元的时隙数(微时隙数)可以受到控制。
具有1ms时间长度的TTI也可以称为常规TTI(LTE Rel.8-12中的TTI)、标准TTI、长TTI、常规子帧、标准子帧、或长子帧等。短于常规TTI的TTI也可以称为压缩TTI、短TTI、部分TTI(partial或fractional TTI)、压缩子帧、短子帧、微时隙、或子时隙等。
另外，长TTI(例如常规TTI、子帧等)也可以用具有超过1ms的时间长度的TTI来替换，短TTI(例如压缩TTI等)也可以用具有比长TTI的TTI长度短且1ms以上的TTI长度的TTI来替换。
资源块(RB，ResourceBlock)是时域和频域的资源分配单元，在频域中，可以包括一个或多个连续的副载波(子载波(subcarrier))。此外， RB在时域中可以包括一个或多个符号，也可以为一个时隙、一个微时隙、一个子帧或一个TTI的长度。一个TTI、一个子帧可以分别由一个或多个资源块构成。另外，一个或多个RB也可以称为物理资源块(PRB，PhysicalRB)、子载波组(SCG，Sub-CarrierGroup)、资源单元组(REG，Resource ElementGroup)、PRG对、RB对等。
此外，资源块也可以由一个或多个资源单元(RE，ResourceElement)构成。例如，一个RE可以是一个子载波和一个符号的无线资源区域。
另外，上述的无线帧、子帧、时隙、微时隙以及符号等的结构仅仅为示例。例如，无线帧中包括的子帧数、每个子帧或无线帧的时隙数、时隙内包括的微时隙数、时隙或微时隙中包括的符号和RB的数目、RB中包括的子载波数、以及TTI内的符号数、符号长度、循环前缀(CP，Cyclic Prefix)长度等的结构可以进行各种各样的变更。
此外，本说明书中说明的信息、参数等可以用绝对值来表示，也可以用与规定值的相对值来表示，还可以用对应的其它信息来表示。例如，无线资源可以通过规定的索引来指示。进一步地，使用这些参数的公式等也可以与本说明书中明确公开的不同。
在本说明书中用于参数等的名称在任何方面都并非限定性的。例如，各种各样的信道(物理上行链路控制信道(PUCCH，PhysicalUplink ControlChannel)、物理下行链路控制信道(PDCCH，PhysicalDownlink ControlChannel)等)和信息单元可以通过任何适当的名称来识别，因此为这些各种各样的信道和信息单元所分配的各种各样的名称在任何方面都并非限定性的。
本说明书中说明的信息、信号等可以使用各种各样不同技术中的任意一种来表示。例如，在上述的全部说明中可能提及的数据、命令、指令、信息、信号、比特、符号、芯片等可以通过电压、电流、电磁波、 磁场或磁性粒子、光场或光子、或者它们的任意组合来表示。
此外，信息、信号等可以从上层向下层、和/或从下层向上层输出。信息、信号等可以经由多个网络节点进行输入或输出。
输入或输出的信息、信号等可以保存在特定的场所(例如内存)，也可以通过管理表进行管理。输入或输出的信息、信号等可以被覆盖、更新或补充。输出的信息、信号等可以被删除。输入的信息、信号等可以被发往其它装置。
信息的通知并不限于本说明书中说明的方式/实施方式，也可以通过其它方法进行。例如，信息的通知可以通过物理层信令(例如，下行链路控制信息(DCI，DownlinkControlInformation)、上行链路控制信息(UCI，UplinkControlInformation))、上层信令(例如，无线资源控制(RRC，RadioResourceControl)信令、广播信息(主信息块(MIB，MasterInformationBlock)、系统信息块(SIB，SystemInformationBlock)等)、媒体存取控制(MAC，MediumAccessControl)信令)、其它信号或者它们的组合来实施。
另外，物理层信令也可以称为L1/L2(第1层/第2层)控制信息(L1/L2控制信号)、L1控制信息(L1控制信号)等。此外，RRC信令也可以称为RRC消息，例如可以为RRC连接建立(RRC Connection Setup)消息、RRC连接重配置(RRC Connection Reconfiguration)消息等。此外，MAC信令例如可以通过MAC控制单元(MAC CE(Control Element))来通知。
此外，规定信息的通知(例如，“为X”的通知)并不限于显式地进行，也可以隐式地(例如，通过不进行该规定信息的通知，或者通过其它信息的通知)进行。
关于判定，可以通过由1比特表示的值(0或1)来进行，也可以 通过由真(true)或假(false)表示的真假值(布尔值)来进行，还可以通过数值的比较(例如与规定值的比较)来进行。
软件无论被称为软件、固件、中间件、微代码、硬件描述语言，还是以其它名称来称呼，都应宽泛地解释为是指命令、命令集、代码、代码段、程序代码、程序、子程序、软件模块、应用程序、软件应用程序、软件包、例程、子例程、对象、可执行文件、执行线程、步骤、功能等。
此外，软件、命令、信息等可以经由传输介质被发送或接收。例如，当使用有线技术(同轴电缆、光缆、双绞线、数字用户线路(DSL，DigitalSubscriberLine)等)和/或无线技术(红外线、微波等)从网站、服务器、或其它远程资源发送软件时，这些有线技术和/或无线技术包括在传输介质的定义内。
本说明书中使用的“系统”和“网络”这样的用语可以互换使用。
在本说明书中，“基站(BS，BaseStation)”、“无线基站”、“eNB”、“gNB”、“小区”、“扇区”、“小区组”、“载波”以及“分量载波”这样的用语可以互换使用。基站有时也以固定台(fixedstation)、NodeB、eNodeB(eNB)、接入点(accesspoint)、发送点、接收点、毫微微小区、小小区等用语来称呼。
基站可以容纳一个或多个(例如三个)小区(也称为扇区)。当基站容纳多个小区时，基站的整个覆盖区域可以划分为多个更小的区域，每个更小的区域也可以通过基站子系统(例如，室内用小型基站(射频拉远头(RRH，RemoteRadioHead)))来提供通信服务。“小区”或“扇区”这样的用语是指在该覆盖中进行通信服务的基站和/或基站子系统的覆盖区域的一部分或整体。
在本说明书中，“移动台(MS，MobileStation)”、“用户终端(userterminal)”、“用户装置(UE，UserEquipment)”以及“终端”这样 的用语可以互换使用。基站有时也以固定台(fixedstation)、NodeB、eNodeB(eNB)、接入点(accesspoint)、发送点、接收点、毫微微小区、小小区等用语来称呼。
移动台有时也被本领域技术人员以用户台、移动单元、用户单元、无线单元、远程单元、移动设备、无线设备、无线通信设备、远程设备、移动用户台、接入终端、移动终端、无线终端、远程终端、手持机、用户代理、移动客户端、客户端或者若干其它适当的用语来称呼。
此外，本说明书中的无线基站也可以用用户终端来替换。例如，对于将无线基站和用户终端间的通信替换为多个用户终端间(D2D，Device-to-Device)的通信的结构，也可以应用本发明的各方式/实施方式。此时，可以将上述的无线基站10所具有的功能当作用户终端20所具有的功能。此外，“上行”和“下行”等文字也可以替换为“侧”。例如，上行信道也可以替换为侧信道。
同样，本说明书中的用户终端也可以用无线基站来替换。此时，可以将上述的用户终端20所具有的功能当作无线基站10所具有的功能。
在本说明书中，设为通过基站进行的特定动作根据情况有时也通过其上级节点(uppernode)来进行。显然，在具有基站的由一个或多个网络节点(networknodes)构成的网络中，为了与终端间的通信而进行的各种各样的动作可以通过基站、除基站之外的一个以上的网络节点(可以考虑例如移动管理实体(MME，MobilityManagementEntity)、服务网关(S-GW，Serving-Gateway)等，但不限于此)、或者它们的组合来进行。
本说明书中说明的各方式/实施方式可以单独使用，也可以组合使用，还可以在执行过程中进行切换来使用。此外，本说明书中说明的各方式/实施方式的处理步骤、序列、流程图等只要没有矛盾，就可以更换顺序。 例如，关于本说明书中说明的方法，以示例性的顺序给出了各种各样的步骤单元，而并不限定于给出的特定顺序。
本说明书中说明的各方式/实施方式可以应用于利用长期演进(LTE，Long Term Evolution)、高级长期演进(LTE-A，LTE-Advanced)、超越长期演进(LTE-B，LTE-Beyond)、超级第3代移动通信系统(SUPER 3G)、高级国际移动通信(IMT-Advanced)、第4代移动通信系统(4G，4th generation mobile communication system)、第5代移动通信系统(5G，5th generation mobile communication system)、未来无线接入(FRA，Future Radio Access)、新无线接入技术(New-RAT，Radio Access Technology)、新无线(NR，New Radio)、新无线接入(NX，New radio access)、新一代无线接入(FX，Future generation radio access)、全球移动通信系统(GSM(注册商标)，Global System for Mobile communications)、码分多址接入2000(CDMA2000)、超级移动宽带(UMB，Ultra Mobile Broadband)、IEEE 802.11(Wi-Fi(注册商标))、IEEE 802.16(WiMAX(注册商标))、IEEE 802.20、超宽带(UWB，Ultra-WideBand)、蓝牙(Bluetooth(注册商标))、其它适当的无线通信方法的系统和/或基于它们而扩展的下一代系统。
本说明书中使用的“根据”这样的记载，只要未在其它段落中明确记载，则并不意味着“仅根据”。换言之，“根据”这样的记载是指“仅根据”和“至少根据”这两者。
本说明书中使用的对使用“第一”、“第二”等名称的单元的任何参照，均非全面限定这些单元的数量或顺序。这些名称可以作为区别两个以上单元的便利方法而在本说明书中使用。因此，第一单元和第二单元的参照并不意味着仅可采用两个单元或者第一单元必须以若干形式占先于第二单元。
本说明书中使用的“判断(确定)(determining)”这样的用语有时包含多种多样的动作。例如，关于“判断(确定)”，可以将计算(calculating)、推算(computing)、处理(processing)、推导(deriving)、调查(investigating)、搜索(looking up)(例如表、数据库、或其它数据结构中的搜索)、确认(ascertaining)等视为是进行“判断(确定)”。此外，关于“判断(确定)”，也可以将接收(receiving)(例如接收信息)、发送(transmitting)(例如发送信息)、输入(input)、输出(output)、存取(accessing)(例如存取内存中的数据)等视为是进行“判断(确定)”。此外，关于“判断(确定)”，还可以将解决(resolving)、选择(selecting)、选定(choosing)、建立(establishing)、比较(comparing)等视为是进行“判断(确定)”。也就是说，关于“判断(确定)”，可以将若干动作视为是进行“判断(确定)”。
本说明书中使用的“连接的(connected)”、“结合的(coupled)”这样的用语或者它们的任何变形是指两个或两个以上单元间的直接的或间接的任何连接或结合，可以包括以下情况：在相互“连接”或“结合”的两个单元间，存在一个或一个以上的中间单元。单元间的结合或连接可以是物理上的，也可以是逻辑上的，或者还可以是两者的组合。例如，“连接”也可以替换为“接入”。在本说明书中使用时，可以认为两个单元是通过使用一个或一个以上的电线、线缆、和/或印刷电气连接，以及作为若干非限定性且非穷尽性的示例，通过使用具有射频区域、微波区域、和/或光(可见光及不可见光这两者)区域的波长的电磁能等，被相互“连接”或“结合”。
在本说明书或权利要求书中使用“包括(including)”、“包含(comprising)”、以及它们的变形时，这些用语与用语“具备”同样是开放式的。进一步地，在本说明书或权利要求书中使用的用语“或(or)”并非是异或。
以上对本发明进行了详细说明，但对于本领域技术人员而言，显然，本发明并非限定于本说明书中说明的实施方式。本发明在不脱离由权利要求书的记载所确定的本发明的宗旨和范围的前提下，可以作为修改和变更方式来实施。因此，本说明书的记载是以示例说明为目的，对本发明而言并非具有任何限制性的意义。

Claims (30)

  1. 一种星座图旋转方法，其中，所述方法包括：
    根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定基站的接收信号的统计特征；其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；
    根据所确定的接收信号的统计特征分别确定各个UE的星座图旋转角度；以及
    根据各个UE的星座图旋转角度对所述一个或多个UE的星座图进行旋转。
  2. 根据权利要求1所述的方法，其中，
    所述根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号随机变量的熵；以及
    所述根据确定的接收信号的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述熵最大时各个UE的星座图旋转角度。
  3. 根据权利要求1所述的方法，其中，
    所述根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的M阶中心距，其中，M为大于或等于2的自然数；以及
    所述根据确定的接收信号的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述接收信号的M阶中心距最大时各个UE的星座图旋转角度。
  4. 根据权利要求2所述的方法，其中，所述确定接收信号随机变量的熵包括：
    确定接收信号随机变量的分布函数；以及
    根据所述接收信号随机变量的分布函数确定所述接收信号随机变量的熵。
  5. 根据权利要求2所述的方法，其中，所述方法进一步包括：对所述接收信号随机变量的熵的表达式进行近似处理，得到所述接收信号随机变量的熵的闭式下限表达式，并将所述接收信号随机变量的熵的闭式下限表达式作为所述接收信号随机变量的熵；以及
    所述根据确定的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述接收信号随机变量的熵的闭式下限表达式最大时各个UE的星座图旋转角度。
  6. 根据权利要求4所述的方法，其中，确定接收信号随机变量的分布函数包括：根据各个UE发送的所有可能的星座点经过物理信道后在基站看到的星座点集合中元素的个数以及噪声和/或干扰的分布函数确定所述接收信号随机变量的分布函数。
  7. 根据权利要求6所述的方法，其中，所述噪声和/或干扰的分布函数为以基站看到的各个UE的信号之和为均值以噪声方差为方差的循环对称高斯分布函数。
  8. 根据权利要求5所述的方法，其中，根据如下公式确定所述接收信号随机变量的熵的闭式下限表达式：
    Figure PCTCN2018079538-appb-100001
    其中，C为一个常数；
    Figure PCTCN2018079538-appb-100002
    代表两个星座点之间的距离，具体 地，
    Figure PCTCN2018079538-appb-100003
    代表
    Figure PCTCN2018079538-appb-100004
    代表
    Figure PCTCN2018079538-appb-100005
    X代表
    Figure PCTCN2018079538-appb-100006
    X JK代表
    Figure PCTCN2018079538-appb-100007
    x 2，k∈χ 2；X LM代表
    Figure PCTCN2018079538-appb-100008
    x 2，m∈χ 2；t代表天线数；σ 2代表噪声。
  9. 根据权利要求1所述的方法，其中，所述方法进一步包括：将各个UE经过星座图旋转后的信号叠加在一起发送。
  10. 一种星座图旋转方法，其中，所述方法包括：
    根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定基站的接收信号的统计特征；其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；
    根据所确定的接收信号的统计特征分别确定各个UE的星座图旋转角度；及
    将各个UE的星座图旋转角度分别通知各个UE。
  11. 根据权利要求10所述的方法，其中，
    所述根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号随机变量的熵；以及
    所述根据确定的接收信号的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述熵最大时各个UE的星座图旋转角度。
  12. 根据权利要求10所述的方法，其中，
    所述根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的统计特征包括：根据一个或多个用户设备UE的信道系数、噪声信息和/或干扰信息确定接收信号的M阶中心距，其中，M为大于或等于2的自然数；以及
    所述根据确定的接收信号的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述接收信号的M阶中心距最大时各个UE的星座图旋转角度。
  13. 根据权利要求11所述的方法，其中，所述确定接收信号随机变量的熵包括：
    确定接收信号随机变量的分布函数；以及
    根据所述接收信号随机变量的分布函数确定所述接收信号随机变量的熵。
  14. 根据权利要求11所述的方法，其中，所述方法进一步包括：对所述接收信号随机变量的熵的表达式进行近似处理，得到所述接收信号随机变量的熵的闭式下限表达式，并将所述接收信号随机变量的熵的闭式下限表达式作为所述接收信号随机变量的熵；以及
    所述根据确定的统计特征分别确定各个UE的星座图旋转角度包括：求解使所述接收信号随机变量的熵的闭式下限表达式最大时各个UE的星座图旋转角度。
  15. 根据权利要求13所述的方法，其中，确定接收信号随机变量的分布函数包括：根据各个UE发送的所有可能的星座点经过物理信道后在基站看到的星座点集合中元素的个数以及噪声和/或干扰的分布函数确定所述接收信号随机变量的分布函数。
  16. 根据权利要求15所述的方法，其中，所述噪声和/或干扰的分布函数为以基站看到的各个UE的信号之和为均值以噪声方差为方差的循环对称高斯分布函数。
  17. 根据权利要求14所述的方法，其中，根据如下公式确定所述接收信号随机变量的熵的闭式下限表达式：
    Figure PCTCN2018079538-appb-100009
    其中，C为一个常数；
    Figure PCTCN2018079538-appb-100010
    代表两个星座点之间的距离，具体地，
    Figure PCTCN2018079538-appb-100011
    代表
    Figure PCTCN2018079538-appb-100012
    代表
    Figure PCTCN2018079538-appb-100013
    X代表
    Figure PCTCN2018079538-appb-100014
    X JK代表
    Figure PCTCN2018079538-appb-100015
    x 2，k∈χ 2；X LM代表
    Figure PCTCN2018079538-appb-100016
    x 2，m∈χ 2；t代表天线数；σ 2代表噪声。
  18. 根据权利要求10所述的方法，其中，所述将各个UE的星座图旋转角度分别通知各个UE包括：通过动态的下行信令将所述各个UE的星座图旋转角度分别通知对应的UE。
  19. 根据权利要求10所述的方法，其中，所述将各个UE的星座图旋转角度分别通知各个UE包括：
    通过准静态的下行信令配置UE的参考星座图旋转角度；以及
    通过动态的下行信令分别通知所述各个UE其星座图旋转角度相对于参考星座图旋转角度的角度偏置。
  20. 根据权利要求10所述的方法，其中，所述将各个UE的星座图旋转角度分别通知各个UE包括：
    预先定义对应不同星座图旋转角度的码本；
    将所述预先定义的码本配置给所述各个UE；以及
    通过动态的下行信令将与所述UE的星座图旋转角度对应的码本索引发送给对应的UE。
  21. 根据权利要求18、19或20所述的方法，其中，所述动态的下 行信令包括：指示位，用于指示所述UE是否进行星座图旋转；以及旋转角度指示域，用于承载所述UE对应的星座图旋转角度、所述UE星座图旋转角度相对于参考星座图旋转角度的角度偏置或与所述UE的星座图旋转角度对应的码本索引。
  22. 一种星座图旋转方法，其中，所述方法包括：
    从基站接收自身的星座图旋转角度，其中，所述星座图旋转角度是由基站根据接收信号的统计特征确定的，所述接收信号为所述基站通过物理信道接收到的一个或多个用户设备UE发送的信号；所述基站根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定所述接收信号的统计特征；以及
    根据所述星座图旋转角度对自身的星座图进行旋转。
  23. 根据权利要求22所述的方法，其中，所述从基站接收自身的星座图旋转角度包括：从基站接收动态的下行信令，从所述动态的下行信令中获取自身的星座图旋转角度。
  24. 根据权利要求22所述的方法，其中，所述从基站接收自身的星座图旋转角度包括：
    从基站接收准静态的下行信令，从所述准静态的下行信令中获取参考星座图旋转角度；
    从基站接收动态的下行信令，从所述动态的下行信令中获取旋转角度偏置；
    根据所述参考星座旋转角度以及旋转角度偏置确定自身的星座图旋转角度。
  25. 根据权利要求22所述的方法，其中，所述从基站接收自身的星座图旋转角度包括：
    从基站接收预先定义的对应不同星座图旋转角度的码本；以及
    从基站接收动态的下行信令，从所述动态的下行信令中获取自身星座图旋转角度对应的码本索引；以及
    根据对应不同星座图旋转角度的码本以及自身星座图旋转角度对应的码本索引确定自身的星座图旋转角度。
  26. 一种基站，其中，所述基站包括：
    处理器；
    与所述处理器相连接的存储器；所述存储器中存储有机器可读指令模块；所述机器可读指令模块包括：
    模型建立模块，用于根据一个或多个UE的信道系数、噪声信息和/或干扰信息确定基站的接收信号的统计特征，其中，所述接收信号为所述基站通过物理信道接收到的所述一个或多个UE发送的信号；以及
    星座图旋转角度确定模块，用于根据所确定的接收信号的统计特征分别确定各个对应UE的星座图旋转角度。
  27. 根据权利要求26所述的基站，其中，所述基站进一步包括：
    测量模块，用于通过信道测量得到各个UE的信道系数。
  28. 根据权利要求26所述的基站，其中，所述基站进一步包括：
    星座图旋转模块，用于根据UE的星座图旋转角度对UE的星座图进行旋转。
  29. 根据权利要求26所述的基站，其中，所述基站进一步包括：
    通知模块，用于将各个UE的星座图旋转角度分别通知各个UE。
  30. 一种计算机可读存储介质，其上存储有计算机指令，其中，所述计算机指令被处理器执行时实现权利要求1至25中任一项所述方法的步骤。
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US11362879B2 (en) 2022-06-14
CN110506412A (zh) 2019-11-26

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