Communications equipment for shaping symbol constellations

Abstract

The present application relates to a first communication device and a second communication device for shaping a symbol constellation in wireless transmission. The first communication device (100) obtains a second symbol constellation based on a first symbol constellation and a set of weights, wherein the first symbol constellation is based on a radiation pattern (600i) in a set of radiation patterns (600a, 600b...600n) of the first communication device (100), and the weights are derived based on the first symbol constellation. Thereafter, a set of antenna elements (106a, 106b...106n) is controlled based on the radiation pattern (600i) to transmit a set of information bits mapped onto the second symbol constellation. Thus, the second symbol constellation is customized for the radio environment to achieve a smart radio having an improved signal design and better performance. In addition, the present application also relates to a corresponding method and a computer program.

Description

Technical Field

[0001] The present application relates to a first communication device and a second communication device for shaping a symbol constellation in wireless transmission. In addition, the present application also relates to a corresponding method and a computer program. Background Art

[0002] There has been some recent interest in using media to facilitate information transmission and reception, where information-carrying signals are manipulated and enhanced on the way to their destination, so that a more reliable wireless link can be established from the transmitter to the receiver. This therefore gives smart radio environments new additional degrees of freedom to further improve network performance. In a smart radio environment, the environment is not a passive entity, but can be changed and customized to enhance network capacity and user experience. To this end, mirrors are used, among other things, to achieve favorable signal manipulation. In this direction, media-based modulation (MBM) is achieved using radio frequency (RF) mirrors mounted near or around the transmit antenna. By using RF mirrors, the transmitted transmit signal is shaped before it reaches its destination. MBM has been proposed for wireless communication systems after 5G, such as for 6G. MBM is an emerging technology that can be an alternative and / or supplement to the modern communication paradigm after 5G networks.

[0003] In the traditional scheme, a single antenna connected to an RF chain transmits radio waves at a given frequency. The transmitting antenna is surrounded by a set of RF mirrors. The transmitted signal passes through the RF mirrors and then exits toward the destination. The information bits are passed to the mirror controller, where, based on the combination of the input bits, a signal is generated to activate the mirror mode corresponding to a given subset of bits. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a solution to reduce or solve the disadvantages and problems of traditional solutions.

[0005] According to a first aspect of the present application, the above and other objects are achieved by a first communication device, and the first communication device includes:

[0006] a collection of antenna elements for operating in a collection of radiation patterns;

[0007] Processor for:

[0008] Acquire a first symbol constellation according to a radiation pattern in a radiation pattern set;

[0009] obtaining a set of weights associated with a first symbol constellation;

[0010] Obtaining a second symbol constellation according to the first symbol constellation and the weight set;

[0011] The set of antenna elements is controlled according to the radiation pattern to transmit a set of information bits mapped onto a second symbol constellation.

[0012] Therefore, the first communication device may also be considered as a transmitter for sending a set of information bits mapped to a second symbol constellation, wherein the second symbol constellation is obtained according to the first symbol constellation and the weight set.

[0013] A symbol constellation may refer herein to a signal point selected from a set of signal points in a signal space, where the signal space may be generated in part by the environment. A signal point may be understood as a signal constellation. An example of a signal space is a two-dimensional complex plane, for which a signal point may be formed as an in-phase and quadrature (I / Q) mapping of the signal space in the complex plane. Higher, multi-dimensional signal constellations may also be formed.

[0014] The radiation pattern can be understood as the directional (eg angular) dependence of the radio wave intensity from an antenna element, measured either close to the antenna element (eg near field) or close to a receiver (eg far field).

[0015] According to the first aspect, the first communication device has the advantage that the second symbol constellation is customized for the radio environment to realize intelligent radio, which has improved signal design and better performance. This can also be understood as symbol shaping achieved by weights, that is, the environment is controlled and used for data transmission.

[0016] According to the first aspect, in an implementation of the first communication device, each antenna element in the set of antenna elements is configured to operate in a plurality of radiation states, so that the set of antenna elements operates in a set of radiation modes.

[0017] According to the first aspect, in an implementation of the first communication device, the set of antenna elements is arranged within a range of a transmitting element for transmitting radio waves, and wherein the set of antenna elements is a set of radio frequency mirrors.

[0018] The radiating element can be considered as a component used to transmit radio waves (e.g., RF signals). For example, this can be achieved by connecting a traditional antenna to an RF chain, which is a cascade of electronic components required to generate and transmit RF signals.

[0019] The advantage of this implementation is that the final symbol space can be generated by a single RF chain, so that the symbol space is enlarged by the antenna elements that receive the RF signal from the transmitting element. This in turn makes the transmitting device cheaper and more compact. This also supports the distributed allocation of antenna elements.

[0020] According to the first aspect, in an implementation manner of the first communication device, obtaining the first symbol constellation includes:

[0021] receiving a set of channel estimates from a second communications device, wherein each channel estimate corresponds to a radiation pattern from a set of radiation patterns;

[0022] A first symbol constellation is calculated based on channel estimates in the set of channel estimates.

[0023] The advantage of this implementation is that the first symbol constellation can be formed, updated and optimized according to channel changes, which achieves transmission with higher rate and higher reliability.

[0024] According to the first aspect, in an implementation manner of the first communication device, obtaining the first symbol constellation includes:

[0025] receiving, from a second communications device, a set of reference signals associated with a set of radiation patterns;

[0026] determining a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern in the set of radiation patterns;

[0027] Calculating a first symbol constellation based on channel estimates in a set of channel estimates; or

[0028] A first symbol constellation is received from a second communications device.

[0029] The advantage of this implementation is that the feedback overhead from the second communication device for obtaining the first symbol constellation can be reduced.

[0030] According to the first aspect, in an implementation manner of the first communication device, calculating the first symbol constellation includes:

[0031] A first symbol constellation is calculated based on channel estimates in a set of channel estimates and a source-based modulation.

[0032] Source-based modulation can be understood as a traditional modulation scheme that changes a digital signal according to the information bits before the RF chain. Examples include M-ary phase shift keying (such as BPSK and QPSK) and M-ary quadrature amplitude modulation (M-QAM) (such as 16QAM and 64QAM).

[0033] The advantage of this implementation is that by using the radiation pattern and source-based modulation, the first symbol constellation can be further enlarged using a joint symbol structure. This results in an enhanced, larger symbol constellation, thereby enabling higher rate transmission. This also enables joint encoding of the radiation pattern and the information bits encoded by the error correction code.

[0034] In an implementation manner of the first communication device according to the first aspect, acquiring the weight set includes:

[0035] receiving a set of channel estimates from a second communications device, wherein each channel estimate corresponds to a radiation pattern from a set of radiation patterns;

[0036] A set of weights is calculated based on the channel estimates in the set of channel estimates and the first symbol constellation.

[0037] The advantage of this implementation is that the feedback overhead for obtaining the weight from the second communication device can be reduced.

[0038] In an implementation manner of the first communication device according to the first aspect, acquiring the weight set includes:

[0039] receiving, from a second communications device, a set of reference signals associated with a set of radiation patterns;

[0040] determining a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern in the set of radiation patterns;

[0041] Calculating a set of weights based on channel estimates in a set of channel estimates; or

[0042] The weights are received from the second communications device.

[0043] The advantage of this implementation is that the feedback overhead for obtaining the weight from the second communication device can be reduced.

[0044] According to the first aspect, in an implementation manner of the first communication device, obtaining the second symbol constellation includes:

[0045] The first symbol constellation is mapped onto a set of weights to obtain a second symbol constellation.

[0046] In this case, the mapping can be understood as a linear mapping.

[0047] The advantage of this implementation is that the enhanced characteristics of the second symbol constellation are achieved through a low-complexity implementation of linear mapping to achieve higher rate or higher reliability transmission.

[0048] According to the first aspect, in an implementation manner of the first communication device, obtaining the second symbol constellation includes:

[0049] After mapping the first symbol constellation to the set of weights, power control and phase shifting are performed to obtain a second symbol constellation.

[0050] The advantage of this implementation is that the second symbol constellation can be formed with the help of phase shifters which can enable a lower complexity and cheaper analog domain or hybrid digital analog implementation.

[0051] According to the first aspect, in an implementation manner of the first communication device, the second symbol constellation is any one of M-PSK or M-QAM.

[0052] M is a positive integer.

[0053] The advantage of this implementation is that backward compatibility with existing communication systems using the above modulation scheme is achieved using weights so that the effective constellation received by the receiver is one of the traditional constellations.

[0054] According to a second aspect of the present application, the above and other objects are achieved by a second communication device, and the second communication device is used to:

[0055] receiving a set of reference signals from a first communications device, wherein the set of reference signals is associated with a set of radiation patterns of a set of antenna elements;

[0056] determining a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern in the set of radiation patterns;

[0057] A first symbol constellation is calculated based on channel estimates in the set of channel estimates.

[0058] According to the second aspect, the second communication device has the advantage that the second symbol constellation is customized to the radio environment to achieve a smart radio with improved signal design and better performance.

[0059] According to the second aspect, in an implementation manner of the second communication device, the second communication device is configured to:

[0060] A first symbol constellation is sent to a first communications device.

[0061] According to the second aspect, in an implementation manner of the second communication device, the second communication device is configured to:

[0062] Calculating a set of weights based on channel estimates in a set of channel estimates and a first symbol constellation;

[0063] The set of weights is sent to the first communications device.

[0064] According to a third aspect of the present application, the above and other objects are achieved by a method for a first communication device, the first communication device comprising a set of antenna elements, the set of antenna elements being used to operate under a set of radiation modes; the method comprising:

[0065] Acquire a first symbol constellation according to a radiation pattern in a radiation pattern set;

[0066] obtaining a set of weights associated with a first symbol constellation,

[0067] Obtaining a second symbol constellation according to the first symbol constellation and the weight set;

[0068] The set of antenna elements is controlled according to the radiation pattern to transmit a set of information bits mapped onto a second symbol constellation.

[0069] The method according to the third aspect can be extended to an implementation corresponding to the implementation of the first communication device according to the first aspect. Therefore, the implementation of the method comprises the features of the corresponding implementation of the first communication device.

[0070] The advantages of the method according to the third aspect are the same as the advantages of the corresponding implementation of the first communication device according to the first aspect.

[0071] According to a fourth aspect of the present application, the above and other objects are achieved by a method for a second communication device, the method comprising:

[0072] receiving a set of reference signals from a first communications device, wherein the set of reference signals is associated with a set of radiation patterns of a set of antenna elements;

[0073] determining a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern in the set of radiation patterns;

[0074] A first symbol constellation is calculated based on channel estimates in the set of channel estimates.

[0075] The method according to the fourth aspect can be extended to an implementation corresponding to the implementation of the second communication device according to the second aspect. Therefore, the implementation of the method comprises the features of the corresponding implementation of the second communication device.

[0076] The advantages of the method according to the fourth aspect are the same as the advantages of the corresponding implementation of the second communication device according to the second aspect.

[0077] According to a fifth aspect, the present application provides a chip, which can be used in a first communication device and / or a second communication device. The chip includes at least one communication interface, at least one processor, and at least one memory, wherein the communication interface, the processor, and the memory are interconnected through a circuit (in some cases, through a bus), and the processor calls instructions stored in the memory to execute the method according to the third or fourth aspect.

[0078] According to a sixth aspect, the present application provides a first communication device and / or a second communication device, comprising a memory and a processor. The memory is used to store program instructions, and the processor is used to call the program instructions in the memory to implement the functions of the first communication device and / or the second communication device in the first aspect or the second aspect.

[0079] According to a seventh aspect, the present application provides a non-volatile storage medium, wherein the non-volatile storage medium stores one or more program codes. When the first communication device and / or the second communication device executes the program code, the first communication device and / or the second communication device executes the relevant method steps executed by the first communication device and / or the second communication device in the third aspect or the fourth aspect.

[0080] The present application also relates to a computer program, wherein the program code, when executed by at least one processor, causes the at least one processor to perform any method according to an embodiment of the present application. Further, the present application also relates to a computer program product, comprising a computer-readable medium and a computer program, wherein the computer program is included in the computer-readable medium and includes one or more of the following groups: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), flash memory, electrically EPROM (EEPROM) and hard disk drive.

[0081] Other applications and advantages of embodiments of the present application will be apparent from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] The drawings are intended to illustrate and explain different embodiments of the present application.

[0083] Figure 1 A block diagram of a first communication device according to an embodiment of the present application is shown.

[0084] Figure 2a shows different radiation patterns, Figure 2b Two different arrangements of antenna elements relative to the radiating elements are shown.

[0085] Figure 3 A method for a first communication device according to an embodiment of the present application is shown.

[0086] Figure 4 A second communication device according to an embodiment of the present application is shown.

[0087] Figure 5 A method for a second communication device according to an embodiment of the present application is shown.

[0088] Figure 6 Yet another embodiment of a second communication device is shown.

[0089] Figure 7 A wireless communication system according to an embodiment of the present application is shown.

[0090] Figure 8 An embodiment of a first communication device is shown that also employs power control and phase shifting.

[0091] Fig. 9 An embodiment of a first communication device that also employs source-based modulation is shown.

[0092] Fig.10 An embodiment of a first communication device is shown which also employs MIMO.

[0093] Fig.11 The relationship between the achievable transmission rate and SNR of the embodiment of the present application is shown.

[0094] Fig.12 A signaling diagram illustrating interactions between a first communication device and a second communication device is shown.

[0095] Fig.13 A flow chart showing an algorithm for calculating a set of weights is shown.

[0096] Fig.14 Two embodiments for shaping the symbol constellation are shown.

[0097] Fig.15 The distribution of minimum pairwise distances for populations of symbol constellations is shown.

[0098] Fig.16 The performance of three different transmission schemes is shown.

[0099] Figures 17a to 17d The shaping of the symbol constellation using a set of weights is shown.

[0100] Fig.18a and Fig.18b The rotation of edge points in the symbol constellation is shown.

[0101] Fig.19 The performance results of different schemes are shown. DETAILED DESCRIPTION

[0102] As mentioned above, the symbol constellation of MBM for a single transmit antenna and a single receive antenna can have a small minimum pairwise distance. The main reason is that the constellation symbols are formed randomly, following the channel distribution law given by the media. Therefore, the minimum pairwise distance of the received symbol constellation of MBM varies from media to media and can be very small. This is why the performance of a single input single output (SISO) MBM (i.e., a single transmit antenna surrounded by an RF mirror with a single antenna receiver) is worse than that of a SISO source-based modulation (i.e., a traditional SISO channel with quadrature amplitude modulation (QAM)). This makes MBM not an attractive candidate for a SISO channel.

[0103] Therefore, the inventors have realized that in terms of signal processing, an improved solution is needed to improve the spectrum efficiency required by future wireless communication systems.

[0104] Figure 1 An embodiment of a first communication device 100 for communicating in a communication system is shown. The first communication device 100 includes a set of antenna elements 106a, 106b ... 106n, and the antenna element sets 106a, 106b ... 106n are used to work under a set of radiation patterns 600a, 600b ... 600n. The first communication device 100 also includes a processor 108, and the processor 108 is used to control the antenna element sets 106a, 106b ... 106n through dotted control lines. The control signal can be formed by the processor 108 and sent to the antenna elements 106a, 106b ... 106n through the wired control line to adjust the state of the antenna element sets 106a, 106b ... 106n. In addition, a wireless solution is also possible (not shown in the figure), in which a wireless control signal is sent from the processor 108 to the antenna element sets 106a, 106b ... 106n for controlling the state. In an embodiment, the wired or wireless control signal may be dependent on the information bits such that the information bits are mapped to the set of radiation patterns 600a, 600b, ... 600n. Thus, the control signal is modified according to the input information bits to configure a given radiation pattern.

[0105] The radiation pattern of the antenna element set 106a, 106b...106n can be understood as the directional dependence of the intensity of the radio waves from the antenna elements. The intensity of the radiation pattern can be measured at different angles (such as azimuth and elevation). In addition to the direction, the radiation pattern can be measured close to the antenna element (such as in the near field) or close to the receiver (such as in the far field). It should be noted that the activation pattern of the antenna element set 106a, 106b...106n produces a radiation pattern. Therefore, in the following disclosure, the term "radiation pattern" is sometimes expressed as an activation pattern. The radiation pattern can also be understood as a transmission beam or a radio beam.

[0106] In addition, the transmitting element 104 is connected to the RF chain block 124, which can be a cascade of electronic components required to generate and send RF signals. The RF chain block 124 provides the RF signal to the transmitting element 104, which is used to transmit radio waves at a given frequency of the RF signal, but is not limited to this. Therefore, the first communication device 100 can also use multiple frequencies or any multi-carrier scheme. Depending on the application, in different configurations or designs, the transmitting element 104 is surrounded by a set of antenna elements 106a, 106b...106n. The transmitted RF signal from the transmitting element 104 propagates toward the set of antenna elements 106a, 106b...106n. In Figure 1 In the embodiment, the radiating element 104 is surrounded by 16 antenna elements, which are arranged cylindrically around the radiating element 104, which is only for the purpose of illustrating one design. However, other arrangements of antenna elements are conceivable, involving the number of antenna elements, the type of antenna elements, and the order, selection and positioning of the antenna elements.

[0107] In addition, the first communication device 100 may further include a bit feed block 120 for feeding information bits to the second communication device 300. The information bits are fed by the bit feed block 120 to a serial-to-parallel conversion block 122 for converting the information bits from serial to parallel to change the radiation pattern. After the serial-to-parallel conversion, the information bits are provided from the serial-to-parallel conversion block 122 to a weight processing block 132, which is controlled by the processor 108 through a dotted control line from the processor 108 to the weight processing block 132.

[0108] The processor 108 of the first communication device 100 may be referred to as one or more general-purpose central processing units (CPU), one or more digital signal processors (DSP), one or more application-specific integrated circuits (ASIC), one or more field programmable gate arrays (FPGA), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, one or more chipsets, but is not limited thereto. Further, the processor 108 may be used to control one or more of the other functional blocks of the first communication device 100.

[0109] According to an embodiment of the present application, the processor 108 is used to obtain a first symbol constellation according to a radiation pattern 600i (where i represents an index number) in an activation pattern set 600a, 600b...600n. Each activation pattern generates a corresponding radiation pattern. The processor 108 is also used to obtain a weight set associated with the first symbol constellation. The processor 108 is also used to obtain a second symbol constellation according to the first symbol constellation and the weight set associated with the first symbol constellation. The processor 108 is also used to control the antenna element set 106a, 106b...106n according to the radiation pattern 600i to send a set of information bits mapped to the second symbol constellation.

[0110] In an embodiment, each antenna element 106n in the antenna element set 106a, 106b ... 106n is used to operate in multiple radiation states, so that the antenna element set 106a, 106b ... 106n operates under the radiation mode set 600a, 600b ... 600n. Multiple radiation states refer to two or more radiation states. Different schemes can be used to achieve different radiation states. For example, in this regard, a varactor can be used to control the antenna elements 106a, 106b ... 106n. Further, the load, polarization and impedance of the antenna element can be controlled to control the radiation state. In addition, changing the spatial position of the antenna elements 106a, 106b ... 106n changes the radiation state. The last example actually changes the physical position of the antenna element, but can still produce different radiation patterns observed from the second communication device 300 for receiving the RF signal from the first communication device 100. This can also be understood as a variant of space shift keying (SSK). The antenna elements 106a, 106b, ... 106n may also include a meta-surface (or any smart surface) to implement meta-surface based modulation.

[0111] Figure 2a Different configurations or activation modes of a set of antenna elements 106a, 106b...106n arranged in a rectangular shape around the radiating element 104 are shown. The set of antenna elements 106a, 106b...106n can have multiple radiation states. In this exemplary illustration, three radiation states of each antenna element 106a, 106b...106n are shown. For example, the radiation state can be created by changing the load of the antenna element using two switches (e.g., diodes) for each antenna element. By changing the load, it is possible to obtain: (a) an open radiation state (i.e., both switches are open), (b) a closed radiation state (i.e., both switches are closed), (c) a half-open or half-closed radiation state (i.e., only one switch is open or closed). Black dots show antenna elements in a closed radiation state, white dots show antenna elements in an open radiation state, and dots with vertical lines show antenna elements in a half-open or half-closed radiation state. By selecting different radiation states of the antenna elements 106a, 106b...106n, different radiation patterns can be obtained. For example, Figure 2a The configuration or activation mode 600a in the embodiment generates a first radiation pattern of the first communication device 100, Figure 2a The activation mode 600b in generates a second radiation mode, Figure 2a The activation mode 600i in produces a third radiation mode and so on.

[0112] In an embodiment, the set of antenna elements 106a, 106b ... 106n is arranged within the range of the transmitting element 104. The range is such that the set of antenna elements will affect the propagation of the RF signal transmitted by the transmitting element 104. It should also be noted that the range can also be regarded as the state of the antenna element as an additional dimension of the design. For example, the set of antenna elements can be placed in the near field (including the reactive near field or the radiating near field) or the far field of the transmitting element 104. The position of the set of antenna elements 106a, 106b ... 106n relative to the transmitting element 104 affects the propagation model of the transmitted wave, so by using the set of weights, the second symbol constellation can be constructed in an advantageous manner in terms of performance.

[0113] therefore, Figure 2b Two different designs of antenna element sets 106a, 106b ... 106n arranged within the range of the radiating element 104 are shown. The antenna element sets 106a, 106b ... 106n are arranged in a manner similar to Figure 2a The same shape is arranged around the radiating element 104. However, in Figure 2b In example A in FIG. 1 , the antenna element is arranged at a distance d1 from the radiating element 104, and in Figure 2b In example B in FIG. 1 , the antenna elements are arranged at a distance d2 from the radiating element 104, where d2>>d1, which means that due to the difference in distance from the radiating element 104, the radiation patterns will be different for examples A and B. That is, in addition to the previous examples of obtaining the radiation state by adjusting the switch (i.e., open, closed, or half-open / half-closed), additional radiation patterns can be obtained by changing the positions of the antenna element sets 106a, 106b...106n. The change in the position of the antenna element set can be performed in the near field case or / and the far field case relative to the radiating element 104. The antenna element sets 106a, 106b...106n can also be grouped so that the antenna elements in each group are at almost the same distance from the radiating element 104, but the distances of these groups from the radiating element 104 can be different. The arrangement of the antenna element sets can be done in any 3D shape, with irregular and regular internal distances between the antenna element sets 106a, 106b...106n.

[0114] In an implementation not shown, the antenna element set 106a, 106b...106n can be mounted directly below the outer shield of the radiating element 104, such as directly below the shield of a conventional base station. In such an example, the antenna elements 106a, 106b...106n can be arranged almost on a regular two-dimensional grid. The size, shape and geometric arrangement of the antenna elements 106a, 106b...106n and the corresponding radiation state of each antenna element can be changed, adapted and optimized for a specific communication scenario, thereby producing more favorable channel conditions.

[0115] In an embodiment, the antenna element set 106a, 106b, ... 106n is controlled by a positive intrinsic negative (PIN) diode (also referred to as an RF switch as described above). In each antenna element, if all PIN diodes are turned on or off at the same time, each antenna element will have two radiation states: a first radiation state, if its PIN diode is turned on, the antenna element is transparent to the incident wave; a second radiation state, if its diode is turned off, the antenna element will reflect the incident wave.

[0116] In an embodiment, antenna element set 106a, 106b ... 106n is an RF mirror set, which can be understood as a device capable of disturbing a radio channel. These disturbances are controlled so that they transmit information from a transmitter to a receiver. For example, an RF mirror can be constructed by the PIN diode and patch antenna mentioned, thereby controlling the disturbance with the help of the PIN diode. Antenna elements can form an intelligent reflecting surface (IRS), a large intelligent surface (LIS), a reconfigurable intelligent surface (RIS), a passive / active relay array (PRA) and a meta-surface (MS). Therefore, the disclosed invention can also be used for this setting. For this case, antenna element set 106a, 106b ... 106n is placed on IRS, LIS, RIS, PRA and MS, and IRS, LIS, RIS, PRA and MS can be located between the transmitter and the receiver. The antenna elements 106a, 106b ... 106n may be allocated or distributed.

[0117] pass represents the set of all radiation patterns of a collection of antenna elements, where m is the total number of PIN diodes that can be turned on and off independently, and π i is a binary sequence of length m, where 1 indicates that the diode is on and 0 indicates that the diode of a given mirror is off. It should be noted that for multiple states of more than two, larger letters can be used to represent the state of the antenna element. Since m is the total number of PIN diodes that can be turned on and off independently, the total number of radiation patterns is equal to 2 m It should be noted that, for example, the binary string π iMight be shorter than the maximum possible length that the entire radiation pattern can provide by not using all antenna elements for practical reasons, or by using antenna elements in a manner related to other antenna elements (i.e. a subset of antenna elements whose diodes are switched on and off simultaneously). If it is assumed that each antenna element has a diode that is switched on and off independently, then m ≤ M, where M is the total number of antenna elements. Radiation pattern set Can realize m-bit transmission.

[0118] In an embodiment, the first communication device 100 receives feedback from the second communication device 300. For example, the first communication device 100 may use the feedback to calculate a weight subject to the power constraint. The weights may be calculated at the second communication device 300 and sent back to the first communication device 100. Another alternative is that the first communication device 100 calculates the weights using a control signal sent by the second communication device 300 to the first communication device 100. The signal points of each radiation pattern are represented as Among them, s i corresponds to π with a unitary weight set i (where i = 1, 2, ..., 2 m ), so that the weights produce the same symbol constellation at the first communication device 100 The second communication device 300 may calculate these signal points using reference signals associated with each radiation pattern, which are sent to the second communication device 300. In one embodiment, the second communication device may use The information is used to calculate the weights subject to the power constraint Weight A new symbol constellation will be generated The combination of the input information bits is mapped to a corresponding radiation pattern with an associated weight. The information bits are passed to the processor 108 of the first communication device 100, in which a control signal is generated based on the combination of the information bits, the control signal activating a radiation pattern in a set of radiation patterns of a set of antenna elements, the combination of the information bits corresponding to a given subset of information bits. Further aspects of the interaction between the first communication device 100 and the second communication device 300 are given in the following disclosure.

[0119] Figure 3 It is shown that the first communication device 100 (for example Figure 11 . Thus, the first communication device 100 includes a set of antenna elements 106a, 106b ... 106n and a processor 108, wherein the set of antenna elements 106a, 106b ... 106n is configured to operate under a set of radiation patterns 600a, 600b ... 600n, and the processor 108 is configured to control the set of antenna elements 106a, 106b ... 106n. The method 200 executable by the processor 108 includes obtaining (202) a first symbol constellation based on a radiation pattern 600i in the set of radiation patterns 600a, 600b ... 600n. The method 200 also includes obtaining (204) a set of weights associated with the first symbol constellation. The method 200 also includes obtaining (206) a second symbol constellation based on the first symbol constellation and the set of weights. The method 200 also includes controlling 208 the set of antenna elements 106a, 106b ... 106n according to the radiation pattern 600i to transmit a set of information bits mapped onto a second symbol constellation.

[0120] Figure 4 FIG. 2 shows a second communication device 300 according to an embodiment of the present application. The second communication device 300 may also be represented as a receiver. Figure 4 In the illustrated embodiment, the second communication device 300 includes a receiving block 302 , a channel estimation block 304 and a first symbol constellation block 306 , which are coupled to each other via communication means known in the art. Further, the receiving block 302 is coupled to an antenna or antenna array 308 .

[0121] The processor 302 of the second communication device 300 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, or one or more chipsets. The memory 306 of the second communication device 300 may be a read-only memory, a random access memory, or a non-volatile random access memory (NVRAM). The transceiver 304 of the second communication device 300 may be a transceiver circuit, a power controller, an antenna, or an interface for communicating with other modules or devices. In an embodiment, the transceiver 304 of the second communication device 300 may be a separate chipset or may be integrated with the processor 302 in a chipset. In some embodiments, the processor 302, the transceiver 304, and the memory 306 of the second communication device 300 are integrated in a chipset.

[0122] According to an embodiment, the receiving block 302 is used to receive a reference signal set from the first communication device 100 via the antenna 308. The reference signal set is associated with a radiation pattern set 600a, 600b ... 600n of the antenna element set 106a, 106b ... 106n of the first communication device 100. The channel estimation block 304 is used to determine a channel estimation set based on the received reference signal set. Each channel estimation corresponds to a radiation pattern 600i in the radiation pattern set 600a, 600b ... 600n of the first communication device 100. The first symbol constellation block 306 is used to calculate a first symbol constellation based on the channel estimates in the channel estimation set.

[0123] In an embodiment, one or more operations performed by the receiving block 302, the channel estimation block 304, and the first symbol constellation block 306 are performed by a processor 302 of the second communication device 300, which may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, or one or more chipsets. The processor may cooperate with a memory of the second communication device 300, which may be a read-only memory, a random access memory, a non-volatile random access memory (NVRAM), or any other suitable memory.

[0124] Figure 5 It is shown that the second communication device 300 (eg Figure 4 Flowchart of a corresponding method 300 performed in a second communication device 300) shown in . The method 400 includes receiving (402) a set of reference signals from a first communication device 100. The set of reference signals is associated with a set of radiation patterns 600a, 600b ... 600n of a set of antenna elements 106a, 106b ... 106n of the first communication device 100. The method 400 includes determining (404) a set of channel estimates based on the received set of reference signals. Each channel estimate corresponds to a radiation pattern 600i in the set of radiation patterns 600a, 600b ... 600n of the first communication device 100. The method 400 also includes calculating (406) a first symbol constellation based on the channel estimates in the set of channel estimates.

[0125] Figure 6Another embodiment of a second communication device 300 is shown. When a pilot is sent from the first communication device 100 to the second communication device 300 (e.g., in DL), the second communication device 300 receives the pilot at an antenna or antenna array 308. The received pilot is demultiplexed in the receiving block 302, i.e., the resources are demapped in the time, frequency, or code domain. The demultiplexed pilot is provided to a channel estimation block 304, which estimates the channel of the radiation pattern associated with the pilot based on the received pilot. The channel estimate is then provided to a first symbol constellation block 306, which forms a first symbol constellation based on the channel estimate. Based on the first symbol constellation, a weight for a given design metric is calculated in a weight calculation block 310. Further, based on the weight and the first symbol constellation, a second symbol constellation is formed in a second symbol constellation block 318 by using a linear mapping, etc. In the demodulation block 312, demodulation is performed on the received symbols using a second symbol constellation with known symbols and their associated bit-to-symbol mapping (i.e., which information bits are carried by different symbols). The demodulation block 312 may calculate log likelihood ratio (LLR) values ​​for different symbols or bits as input to the decoding block 314. To calculate the LLR values, the demodulation block 312 may also use the channel estimate from the channel estimation block 304 as input. Thereafter, the demodulated symbols are decoded in the decoding block 314. The information sink block 316 receives the decoded symbols from the decoding block 314 for the desired application. Further, a feedback signal is formed in the feedback generator 320 based on any combination of the channel estimate from the channel estimation block 304, the first symbol constellation from the first symbol constellation block 306, the weights from the weight calculation block 310, and the second symbol constellation from the second symbol constellation block 318, or any indication of these parameters, which may include compression, a change in a parameter, or an index based on a predefined table. The feedback signal is sent to the first communication device 100.

[0126] It should be noted that, in an embodiment, when the pilot is transmitted from the second communication device 300 to the first communication device 100 in the opposite direction (e.g., in UL), the weight and the second symbol constellation may be calculated at the first communication device 100 using the same method as used in the second communication device 300. Therefore, feedback signaling from the second communication device 300 may be eliminated or reduced. In some cases, the first communication device 100 may use a control channel to notify the second communication device 300 of the second symbol constellation.

[0127] In an embodiment, when forming a conventional symbol constellation which can be achieved by selecting appropriate weights, there is no need to inform the demodulation block 312 and the decoding block 314 of the second symbol constellation because the weights are calculated to generate a symbol constellation having the same constellation points as the conventional symbol constellation.

[0128] Figure 7 A wireless communication system 500 according to an embodiment of the present application is shown. The wireless communication system in the present application includes but is not limited to LTE, 5G or any future wireless communication system. The wireless communication system 500 includes a first communication device 100 and a second communication device 300 for communicating in the wireless communication system 500. For simplicity, Figure 7 The wireless communication system 500 shown includes only the first communication device 100 and the second communication device 300. However, the wireless communication system 500 may include any number of first communication devices and any number of second communication devices without departing from the scope of the present application.

[0129] exist Figure 7 In the wireless communication system 500 shown, the first communication device 100 acts as a network access node (e.g., gNB) or is included in a network access node (e.g., gNB), and the second communication device 300 acts as a client device (e.g., UE) or is included in a client device (e.g., UE). However, it should be noted that the opposite situation is possible, that is, the first communication device 100 acts as a client device and the second communication device 300 acts as a network access node. In an exemplary scenario, the first communication device 100 and the second communication device 300 can communicate with each other in a downlink (DL) and / or an uplink (UL) via a Uu interface.

[0130] The client devices in the present application include but are not limited to: UE, such as smartphones, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, personal digital assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to wireless modems, vehicle-mounted devices, wearable devices, integrated access and backhaul (IAB) nodes, such as mobile cars or devices installed in cars, drones, device-to-device (D2D) devices, wireless cameras, mobile stations, access terminals, user units, wireless communication devices, wireless local access network (WLAN) stations, wireless-enabled tablets, laptop embedded devices, universal serial bus (USB) converters, wireless customer-premises equipment (CPE) and / or chipsets. In the context of the Internet of Things (IOT), a client device may refer to a machine or another device or chipset that performs communication with another wireless device and / or a network device.

[0131] UE may also be referred to as a mobile phone, a cellular phone, a computer tablet or a laptop with wireless capabilities. In this context, a UE may be, for example, a portable, pocket-storage, handheld, computer-based or vehicle-mounted mobile device capable of sending voice and / or data to another entity (e.g., another receiver or server) through a wireless access network. A UE may be a station (STA), which is any device that includes a media access control (MAC) and physical layer (PHY) interface to a wireless medium (WM) that complies with IEEE 802.11. A UE may also be used to communicate in 3GPP-related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth-generation wireless technologies (e.g., NR).

[0132] The network access nodes of the present application include but are not limited to: NodeB in a wideband code division multiple access (WCDMA) system, evolutionary Node B (eNB) or evolved NodeB (eNodeB) in an LTE system, or a relay node or access point in a fifth generation (5G) network, or a vehicle-mounted device, a wearable device or a gNB.

[0133] Further, the network access node in this article can be represented as a wireless network access node, an access network access node, an access point or a base station, such as a radio base station (RBS), which in some networks may be referred to as a transmitter, "gNB", "gNodeB", "eNB", "eNodeB", "NodeB" or "B node" depending on the technology and terminology used. Depending on the transmission power and cell size, the wireless network access node can be of different categories, such as a macro eNodeB, a home eNodeB or a micro base station. A wireless network access node can be a station (STA), which is any device that includes a MAC and PHY interface to a wireless medium that complies with IEEE 802.11. The wireless network access node can also be a base station corresponding to a 5G wireless system.

[0134] In an embodiment, power control and phase shifting are also used. Figure 8 . Thus, obtaining the second symbol constellation includes: after mapping the first symbol constellation onto the weight set, performing power control and phase shifting to obtain the second symbol constellation. Therefore, the symbol constellation shaping of the first symbol constellation is implemented by two separate blocks, namely the power control and weight processing block 132 and the phase shift block 134. Both blocks are configured and controlled by the processor 108 via a dotted control line extending from the processor 108. The power control and weight processing block 132 is capable of changing the distance between the symbol point and the origin in the two-dimensional plane, and the phase shift block 134 (or equivalently, the delay block) is capable of rotating the symbol in the two-dimensional plane. The combination of these two operations supports the formation of a favorable second symbol constellation. The phase shift block 134 (or equivalently, the delay block) can be implemented in the analog domain, or in conjunction with the antenna element, or as part of the antenna element. The power control and weight processing block 132 and the phase shift block 134 can be used for all radiation modes of the first communication device 100. The power controller or phase shifter can be configured using a quantization step. For example, a power controller or phase shifter may be configured according to a formula where the step size of the power and / or phase adjustment varies according to the symbol constellation or channel variation.

[0135] In an embodiment, conventional source-based modulation is also used to calculate Fig. 9 . Thus, calculating the first symbol constellation includes calculating the first symbol constellation based on the channel estimates in the channel estimate set and source-based modulation. Source-based modulation can be understood as a traditional modulation scheme that changes a digital signal according to information bits before passing through the RF chain 124. Examples include M-ary phase shift keying (such as BPSK and QPSK) and M-ary quadrature amplitude modulation (M-QAM) (such as 16QAM and 64QAM).

[0136] The first communication device 100 includes a Fig. 9 The bit separation block 126 after the serial-to-parallel block 122 in FIG. Assume that each symbol point of the source-based modulation can carry m1 bits per signal point. That is, for QPSK and 16QAM, m1 is equal to 2 and 4, respectively. Then, the radiation pattern set The transmission of m2 bits per channel can be achieved. The serial-to-parallel block 122 groups the information bits into m1+m2 bits. Then, in the bit separation block 126, the grouped bits are separated into m1 bits and m2 bits, where the m1 bits determine the symbol point of the source-based modulation and the m2 bits correspond to one of the radiation patterns in the set of radiation patterns. The weight set supports shaping the symbols. The weight set can be used to change the bit of all inputs. Therefore, the weights of the first implementation and the second implementation are respectively and Therefore, the effective symbol constellation generated by the source-based modulation and radiation pattern is enlarged so that m1+m2 bits per symbol can be carried, and the spectrum efficiency and link throughput are improved.

[0137] Fig. 9 The first communication device 100 in the embodiment may also optionally include a feeder 144. If the first communication device 100 includes a feeder 144, in addition to the radiation pattern obtained by selecting an activation mode for the antenna element set 106a, 106b...106n, the selection of symbols obtained by source-based modulation may also change the weights. An advantage of this implementation is that the hybrid second symbol constellation obtained by source-based modulation and the antenna elements (i.e., different radiation patterns) can be jointly optimized. This in turn achieves a second symbol constellation with improved performance.

[0138] If the first communication device 100 does not include the feeder line 144 ( Fig. 9 ), the number of weights for optimization that depend only on the antenna elements is reduced, thereby reducing the complexity of the second symbol constellation optimization, but the performance is poorer than the solution with the feed line 144.

[0139] The bit separation block 126 also arranges the information bits into two information bit sequences, which can be binary bit sets. The two information bit sequences can be joint or disjoint information sets. The first information bit sequence is fed to the source-based modulator 142, and the second information bit sequence is fed directly to the processor 108, which adjusts the weights and antenna elements 106a according to the second information bit sequence when receiving.

[0140] Examples of source-based modulation include, but are not limited to, source modulation, such as phase-shift keying (PSK), such as binary PSK (BPSK) and quadrature PSK (QPSK); quadrature amplitude modulation (QAM), such as 16QAM and 64QAM.

[0141] In an embodiment, multiple-input multiple-output (MIMO) is also used, which Fig.10 When two or more RF chains are used at the first communication device 100, the conventional MIMO system can be enhanced by this solution to further improve the capacity. It should be noted that, for simplicity, Fig.10 The example in FIG. 1 only shows two MIMO branches and their corresponding RF chains, but it should be noted that the first communication device 100 may include any number of suitable MIMO branches.

[0142] Fig.10The first communication device 100 is shown using joint source-based modulation with MIMO. In addition, the first communication device 100 includes a precoding block 152, which is arranged between the source-based modulation block 142 and the weight processing blocks 132, 132', and the weight processing blocks 132, 132' are controlled by the corresponding processors 108, 108' through the dotted control line. The source modulation bits from the source modulation block 142 are provided to the precoding block 152, and the precoding block 152 precodes the received symbols. The precoding can be adjusted according to the selected radiation mode, or vice versa, wherein the processor 108, 108' is suitable for the selection of the precoder. The above-mentioned source modulation can be used. It is assumed that each symbol point of the source-based modulation can carry each symbol point m1 bit. That is, for QPSK and 16QAM, m1 is equal to 2 and 4, respectively. The precoding in the first communication device 100 can be performed digitally like the precoding in LTE and NR, where the receiver (i.e., the second communication device 300) also receives a rank indication (RI) and a precoding matrix index (PMI). The first communication device 100 based on the selection of RI and PMI through the feedback line can further adjust its antenna elements to create a radiation pattern for a given metric that enhances the quality of service (QoS).

[0143] A non-limiting example of a MIMO implementation is given herein to better understand the implementation. Assume there are two transmitting elements 104, 104', each of which is surrounded by a set of antenna elements, such as Fig.10 Next, consider two feedback bits sent from the second communication device 300 to the first communication device 100 via control signaling, which are used to notify the first communication device 100 to select and activate a suitable activation mode. Fig.10 1 and provided to the precoding block 152. Single rank transmission with different PMIs is considered, i.e., RI=1. For NR, there are 4 indices with 4 different precoding matrices. Next, a design using these precoding matrices and the proposed scheme is disclosed. To this end, in the disclosed scheme, two additional feedback bits are sent from the second communication device 300 to the first communication device 100 via control signaling for selecting the activation mode. The feedback is in Fig.10 It is shown as Feedback_2 in the figure and provided to the weight processing blocks 132, 132' and the corresponding processors 108, 108'.

[0144] Table 1 shows an example design of using such an NR precoding matrix in MIMO. The first column shows the joint index, with a total of 4 feedback bits indicating 16 indices as shown in the second column. The first two bits indicate the activation mode (column 3), and the remaining two bits select the precoding matrix (column 4) by which the modulation symbols obtained by the source-based modulation are precoded using the indication bits in the feedback.

[0145] Fig.11 The rate in bits per channel use (bpcu) is shown as a function of SNR (in dB). The dashed line shows the conventional baseline MIMO scheme with precoding, and the solid line shows the disclosed scheme with precoding. It can be observed that the disclosed scheme provides a power gain of multiple dB compared to the conventional scheme.

[0146] Table 1

[0147]

[0148]

[0149] Fig.12 A signaling diagram showing interaction between a first communication device 100 and a second communication device 300 in a communication system 500 according to an embodiment of the present application is shown.

[0150] exist Fig.12In step I, the first communication device 100 sends a reference signal (RS) set or a pilot set corresponding to a radiation pattern (or activation pattern) set to the second communication device 300. In general, the first communication device 100 sends at least one reference signal or pilot for each radiation pattern in the radiation pattern set of the antenna element set. Non-limiting examples of reference signals are sounding reference signals (SRS), demodulation reference signals (DMRS), or channel state information reference signals (CSI-RS). New reference signals used only for this specific application (e.g., mirror state information reference signals (MSI-RS) designed for this specific application) can also be envisioned to be included in future standards. RS can be sent using various sequences. One example includes mutually orthogonal sequences sent in time or frequency in addition to code division of pilot sequences. The use of covering codes that depend on antenna elements can also be considered. Pilots can be sent for a subset of activation patterns or a subset of antenna elements to reduce pilot overhead. It should be noted that RS can be sent from the second communication device 300 to the first communication device 100 in other directions to perform the same process. This method is more useful when there is time division duplexing or partial reciprocity in frequency division duplexing, where the partial reciprocity of UL and DL applies to angle and channel delay.

[0151] In the case of the above-mentioned PIN diode-implemented antenna element, represents the set of all radiation patterns, where m is the total number of PIN diodes that can be turned on and off independently, and π i is a binary sequence of length m, where 1 indicates that the PIN diode is on and 0 indicates that the PIN diode of a given mirror is off. If it is assumed that each antenna element has a PIN diode that is turned on and off independently, then m ≤ M, where M is the total number of antenna elements. Therefore, for this implementation, a time-division multiplexed 2 m The first communication device 100 may decide to send pilots only for a subset of the radiation patterns to reduce overhead, thereby allowing the second communication device 300 to obtain a complete symbol constellation through other signal processing methods such as interpolation.

[0152] exist Fig.12In step II, the second communication device 300 estimates a radio channel of each radiation pattern in the radiation pattern set according to the received reference signal set. The estimated channel of each radiation pattern represents a constellation symbol in the received symbol constellation.

[0153] In an embodiment, the second communication device 300 may optionally send channel estimates 610a, 610b, ... 610n to the first communication device 100, as shown by the dashed arrows extending from block II. In this case, Fig.12 The subsequent steps III to V in may not be performed by the second communication device 300. The signaling of the channel estimate 610a, 610b ... 610n may be an indication of the channel estimate, for example mapped to a table, indexed by a binary bit string, or compressed or differentially indicated from a previous channel estimate sent to the first communication device 100.

[0154] exist Fig.12 In step III, the second communication device 300 calculates a first symbol constellation, also called a baseline signal space constellation. The symbol point set of all radiation patterns is represented as Among them, the symbol point s i Corresponding to the radiation mode π i , where i = 1, 2, ..., 2 m It should be noted that the symbol s is used i , which also indicates a radiation pattern π i The channel in the transmitted signal is actually the transmitted signal shaped by the specific configuration (or activation pattern) of the antenna elements. It can also be understood as a constellation of symbols in symbol space.

[0155] Optionally, the second communication device 300 may directly send the first symbol constellation S1 (set ), as shown by the dashed arrow extending from the box III. In this case, steps IV and V may not be performed by the second communication device 300.

[0156] exist Fig.12 In step IV, the second communication device 300 uses the first symbol constellation The information is used to calculate the complex set of weights subject to the power constraint Fig.13 The flowchart of calculating the weight set in detail is shown. Calculate the complex weight set w i (where i = 1, 2, ..., 2 m ), the symbol at the second communication device 300 is represented by The purpose of the complex weight set is to shape the received symbol constellation so that the symbol set Has better characteristics, enabling transmission with better quality of service.

[0157] exist Fig.12 In step V of , after calculating the complex weight set, the second communication device 300 provides feedback signaling to indicate the calculated complex weight set {w i}, where i = 1, 2, ..., 2 m .

[0158] In practice, it is desirable that the feedback signaling overhead is low. To achieve this, the feedback signaling may be compressed to reduce the overhead. In an embodiment, the feedback is formed and represented by a binary string containing only a few bits. Assuming the simplest form, i.e., the second communication device 300 obtains a radiation pattern for each antenna element, therefore, if there are N antenna elements with RF chains t There are m total radiation modes in a system with 1 antenna, so the feedback overhead is mN t That is, for each of the two transmit antennas having 2 radiation patterns, only 2 bits of feedback from the second communication device 300 to the first communication device 100 are required to configure the first communication device 100 .

[0159] exist Fig.12 In step VI, the first communication device 100 obtains a second symbol constellation according to the weight set received from the second communication device 300 and the first symbol constellation.

[0160] In an embodiment, the first communication device 100 obtains the second symbol constellation by mapping the first symbol constellation onto a set of weights. The mapping may be a linear mapping. A simple example of a linear mapping is an element-wise multiplication of the weights with the first symbol constellation to generate the second symbol constellation.

[0161] In an embodiment, after mapping the first symbol constellation to a set of weights, power control and phase shifting are performed to obtain a second symbol constellation.

[0162] In an embodiment, the second symbol constellation is any one of M-PSK (e.g., BPSK and QPSK) or M-QAM (e.g., 16-QAM and 64QAM), where M is a positive integer. A set of weights may be calculated so that the symbols in the second symbol constellation form a conventional symbol constellation so that the transmission may be accessed by another conventional receiver of the second communication device 300. Other examples are weights obtained so that the new symbol constellation has an enhanced shaping gain (this is known in coding theory and is achieved, for example, by optimizing the probability distribution of the position constellation points or signal points in the signal space). Weights may also be obtained so that a new symbol constellation is generated to form a multidimensional lattice having a desired generating matrix having a fundamental parallelotope. The properties of the lattice may be optimized using weights that adapt the lattice to some channel conditions.

[0163] exist Fig.12 In step VII, the first communication device 100 sends the information bit set mapped to the calculated second symbol constellation S2 in step VI to the second communication device 300.

[0164] exist Fig.12 In step VIII, the second communication device 300 receives a set of information bits mapped onto the calculated second symbol constellation S2. The second communication device 100 then demodulates and decodes the received information according to the second symbol constellation and the used bit-to-symbol mapping.

[0165] However, in an embodiment, the first communication device 100 may acquire the weight set in an alternative manner, rather than directly receiving the weight set from the second communication device 300 .

[0166] In an embodiment, the first communication device 100 receives a set of channel estimates 610a, 610b, ... 610n from the second communication device 300, which corresponds to Fig.12 Optional transmission in step II. Each channel estimate corresponds to a radiation pattern 600i in the set of radiation patterns 600a, 600b ... 600n. The first communications device 100 also calculates a set of weights based on a channel estimate 610n in the set of channel estimates 610a, 610b ... 610n and the first symbol constellation.

[0167] In the embodiment, the first communication device 100 receives the data from the second communication device 300 ( Fig.12, 610a, 610b, . . . 610n) receives a reference signal set associated with a radiation pattern set, and determines a channel estimate set 610a, 610b, . . . 610n based on the received reference signal set. Each channel estimate corresponds to a radiation pattern in the radiation pattern set. Then, the first communication device 100 calculates a weight set based on the channel estimates in the channel estimate set. Therefore, this case involves an example in which the second communication device 300 (rather than the first communication device 100) sends a reference signal to estimate a radio channel, such as Fig.12 This is possible because the antenna elements are reciprocal with respect to transmission and reception of RF signals.

[0168] In addition, the first communication device 100 may also obtain the first symbol constellation in different ways.

[0169] In an embodiment, the first communication device 100 receives a set of channel estimates 610a, 610b, ... 610n from the second communication device 300 (see Fig.12 Each channel estimate corresponds to a radiation pattern 600i in the set of radiation patterns 600a, 600b ... 600n. The first communication device 100 calculates a first symbol constellation based on a channel estimate 610n in the set of channel estimates 610a, 610b ... 610n.

[0170] In an embodiment, the first communication device 100 receives a reference signal set associated with a radiation pattern set from the second communication device 300, and determines a channel estimation set based on the received reference signal set. Each channel estimation corresponds to a radiation pattern in the radiation pattern set. The first communication device 100 calculates a first symbol constellation based on the channel estimation in the channel estimation set. This case also involves an example in which the second communication device 300 (rather than the first communication device 100) sends a reference signal to estimate a radio channel. This is possible because the antenna element set is reciprocal in terms of transmission and reception of RF signals.

[0171] In an embodiment, the first communication device 100 directly receives the first symbol constellation from the second communication device 300 through control signaling, such as Fig.12 As shown by the dotted arrow at box III. For example, the first symbol constellation can be selected from a predetermined codebook set known to both the first communication device 100 and the second communication device 300. Therefore, only the codebook index needs to be sent, thereby reducing control signaling overhead.

[0172] also, Fig.13 A flowchart of an algorithm for calculating the weight set in detail is shown. The algorithm uses a random perturbation method for a given design metric.

[0173] exist Fig.13In step I, an initial first symbol constellation is formed for all radiation patterns.

[0174] exist Fig.13 In step II, an initial complex weight set corresponding to all radiation patterns in the radiation pattern set is set.

[0175] exist Fig.13 In step III, the metric is calculated. The algorithm sets the design metric and converts it into The initial signal space formed is taken as its input and generates a complex set of weights subject to the power constraint As its output, the power constraint may be an average or peak power constraint.

[0176] The design metrics are set in step IV and provided to step III. The design metrics may include minimum pairwise distance, e.g., Euclidean distance, or any other relevant distance metrics, such as chord distance, Shannon capacity, symbol error rate, block error rate, finite length capacity, bit interleaving capacity, outage capacity, and shaping gain, which are commonly used for incoherent communications. Delay constraints and reliability may also be used as design metrics.

[0177] exist Fig.13 In step V, the initial set of weights is perturbed. In one example, the weights are perturbed in a random manner such that:

[0178] Where k = 1, 2, ...

[0179] in, represents the disturbance variable selected according to a given random distribution, α k represents the power normalization factor. The algorithm first starts with the unit weight Start (where i = 1, 2, ..., 2 m ). That is, for level (k), the disturbance Applied to the earlier selected weight associated with the i-th signal point The i-th weight is found at . One distribution that can be used is: first, from the integers {1,2,…,2 m}, and then for the selected index, set a uniform cyclic distribution to select the perturbation The support for the uniform distribution changes over time, allowing the perturbation to become smaller as the algorithm runs. For other unselected indices, no perturbation is applied.

[0180] In step VI, the new signal constellation (i.e., symbol constellation) is obtained by a simple linear mapping (using element-wise multiplication) through the set formed.

[0181] In step VII, a metric is calculated. For example, the minimum pairwise Euclidean distance is considered as the objective function. The objective function is recalculated.

[0182]

[0183] In step VIII, if the perturbation produces a larger minimum distance, d k >d k-1 , then the perturbation is accepted, otherwise, a new random perturbation is selected until the design metric is enhanced.

[0184] In step IX, the process continues, namely Fig.13 The No branch in , until the metric does not change significantly or the total number of trials selected for optimization is exhausted. Otherwise, select Fig.13 The "Yes" branch in the command is executed and step X is executed.

[0185] In step X, after finding the complex weight w i (where i = 1, 2, ..., 2 m ), these weights (or signals indicating these weights) are fed back to the first communication device 100. The new symbol constellation at the second communication device 300 is composed of the set It indicates that, is a set of weights.

[0186] Fig.14 Two examples of the scheme disclosed herein for shaping the symbol constellation are shown. In these examples, there are four antenna elements (whose PIN diodes can be turned on and off independently), i.e., m=4, which produces a signal with 2 m =16-point signal constellation. The first symbol constellation is composed of The second symbol constellation is represented by It indicates that, is a set of weights calculated using an algorithm by maximizing the minimum pairwise distance subject to a power constraint. It is assumed that the channel from each antenna element to the second communication device 300 follows Rayleigh fading with unit variance. From Fig.14 As can be seen from these examples in , the first symbol constellation has a small minimum pairwise distance and the symbol points are irregularly distributed on the two-dimensional plane. This is shown in the upper two figures, however, the disclosed scheme by introducing a set of weights can shape the first symbol constellation in a favorable way according to the design criteria to obtain the second symbol constellation. Since the minimum pairwise distance is chosen as the design metric, the algorithm works in a way that the symbols in the second symbol constellation are placed on almost a triangular grid, which has a better minimum pairwise distance, as shown in the lower two figures.

[0187] Fig.15The distribution of the minimum pairwise distances of the symbol constellation populations according to the conventional scheme and the disclosed scheme is shown. In this example, there are four antenna elements (whose diodes can be turned on and off independently), i.e., m=4, which gives m = 16-point symbol constellation. It is assumed that the radio channel from each antenna element to the second communication device 300 follows Rayleigh fading with unit variance.

[0188] Fig.15 The previous figure in shows the distribution:

[0189]

[0190] in, represents the symbol constellation according to the conventional scheme.

[0191] on the other hand, Fig.15 The next figure in shows the distribution:

[0192]

[0193] in, Represents the disclosed scheme, so that is a set of weights that is used to maximize compliance with Fig.13 The algorithm for computing the minimum pairwise distance with the power constraint given in . Fig.15 It can be seen that the traditional scheme has a smaller minimum pairwise distance and a significant probability, while the disclosed scheme has a larger minimum pairwise distance. This shows that the disclosed scheme can achieve a symbol constellation with better characteristics, thereby achieving a higher quality of service.

[0194] Fig.16 The relationship between the symbol error probability (SER) and the signal-to-noise ratio (Es / No) for three different transmission schemes is shown.

[0195] Scheme 1 is a baseline open-loop MBM according to the conventional scheme, where there are four antenna elements (whose diodes are turned on and off independently), i.e. m=4, which gives a m = 16-point symbol constellation. It is assumed that the channel from each antenna element to the receiver follows independent Rayleigh fading with unit variance and AWGN noise at the receiver. Scheme 2 is a disclosed closed-loop MBM according to an embodiment similar to that of Scheme 1, where there are four antenna elements (whose diodes can be turned on and off independently), i.e. m = 4, which gives a signal with 2 m = 16-point symbol constellation, but the transmitter can configure weights for each channel variation. The channel from each image to the receiver is assumed to follow Rayleigh fading with unit variance. Scheme 3 is conventional 16QAM modulation over AWGN and is considered the benchmark.

[0196] from Fig.16 It can be concluded that the disclosed scheme significantly improves the baseline MBM scheme, which achieves tens of dB of power gain at low SER. In addition, the disclosed scheme operates near an AWGN channel.

[0197] Furthermore, in the following disclosure, the transmission of low density parity check (LDPC) coded bits using a conventional scheme is considered. In the following, it is assumed that the transmitter has four antenna elements (whose PIN diodes can be turned on and off independently), i.e., m=4. This yields a signal with 2 m = 16-point symbol constellation. According to the traditional scheme, the symbol constellation is composed of Indicates that the public symbol constellation is composed of It indicates that, is the set of weights computed using the algorithm by maximizing the minimum pairwise distance subject to the power constraint. Fig.17a shows the symbol space when no weight set is used, Fig.17b It shows that when the weight set The symbol space used for the disclosed scheme when shaping the first symbol constellation. The symbol points of the second symbol constellation are located on a two-dimensional triangular grid, such as Fig.17c shown.

[0198] In order to achieve the transmission of bits, it is also necessary to design a mapping of bits to symbols. One approach is to use a perturbation method so that the design metric, the Hamming distance from the bit label to the nearest neighbor, is minimized. The perturbation can start with an initial random mapping and then perform random bit flips. Other optimization methods can also be applied. Fig.17d An example of the results obtained by perturbation is shown. It can be seen that the mapping can be described so that the symbols are grouped so that the symbols are located in different rows, and then two bits are allocated for each row, and two additional bits are allocated to distinguish the symbols on each row. That is, the string b0b1b2b3 is assigned so that b0b1 indicates one of the four rows and b2b3 determines one of the four symbol points on each row. It is also observed that the symbol constellation obtained using this method gives some edge points. Rotation of these edge points can provide enhanced performance by supporting finding a better bit-to-symbol mapping, such as Fig.18a and Fig.18b shown.

[0199] Fig.18b shows the second symbol constellation after applying the initial weights, Fig.18a The same constellation with rotated edge points is shown. Fig.18aThe symbol constellation when two edge points are surrounded is shown, wherein the rotation angle of the corresponding symbol point can be calculated and the corresponding weight can be readjusted. It should be noted that the rotation does not change the transmission power.

[0200] Fig.19 The bit error rate (BER) of four LDPC transmission code schemes is shown as a function of SNR in dB when the code rate is half, these four schemes are: baseline open-loop MBM according to the conventional scheme, closed-loop MBM according to the disclosed embodiment, closed-loop MBM with rotated edge points according to the disclosed embodiment, and the conventional scheme of 16QAM on AWGN as a baseline. The Shannon limit is also shown. From Fig.19 It can be concluded that the disclosed scheme significantly improves the baseline MBM scheme with multiple dB of power gain, achieving significant energy savings. Alternatively, the scheme can also be used to extend coverage. Rotation of the edge points can further improve the performance and make the disclosed scheme work almost as well as 16QAM transmission on AWGN channels.

[0201] One of the main achievements of the present application is that by using the disclosed scheme, a fading channel can be converted into an AWGN channel. That is, it can be seen that the present application effectively achieves channel hardening by using weights to remove randomness in the effective radio channel so that fading is used for data transmission. Therefore, the scheme can be understood as: by converting a fading channel into an AWGN channel and controlling the fading of data transmission at the same time, symbol shaping is achieved, thereby achieving channel hardening.

[0202] In addition, any of the methods provided by the embodiments of the present application can be implemented in a computer program having a codec module, and when a processing device runs the computer program, the computer program causes the processing device to perform the method steps. The computer program is included in a computer-readable medium of a computer program product. The computer-readable medium can basically include any memory, such as a read-only memory (ROM), a programmable read-only memory (PROM), an erasable PROM (EPROM), a flash memory, an electrically erasable EPROM (EEPROM), or a hard disk drive.

[0203] According to an embodiment, the present application provides a chip, which can be used for a first communication device and / or a second communication device. The chip includes at least one communication interface, at least one processor, and at least one memory, wherein the communication interface, the processor, and the memory are interconnected through a circuit (in some cases, through a bus), and the processor calls instructions stored in the memory to execute a method according to an embodiment of the present application.

[0204] According to an embodiment, the present application provides a first communication device and / or a second communication device, including a memory and a processor. The memory is used to store program instructions, and the processor is used to call the program instructions in the memory to implement the functions of the first communication device and / or the second communication device according to an embodiment of the present application.

[0205] According to an embodiment, the present application provides a non-volatile storage medium that stores one or more program codes. When the first communication device and / or the second communication device executes the program code, the first communication device and / or the second communication device executes the relevant method steps performed by the first communication device and / or the second communication device according to an embodiment of the present application.

[0206] Furthermore, the skilled person may appreciate that embodiments of the first communication device 100 and the second communication device 300 include necessary communication capabilities in the form of functions, modules, units, elements, etc., for performing the scheme. Examples of other such devices, units, elements, and functions are: processors, memories, buffers, control logic, encoders, decoders, rate matchers, derate matchers, mapping units, multipliers, decision units, selection units, switches, interleavers, deinterleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoders, TCM decoders, power supply units, power supply feeds, communication interfaces, communication protocols, etc., which are appropriately arranged together to perform the scheme.

[0207] In particular, for example, the processors of the first communication device 100 and the second communication device 300 may include one or more instances of a central processing unit (CPU), a processing unit, a processing circuit, a processor, an application specific integrated circuit (ASIC), a microprocessor, or other processing logic that can interpret and execute instructions. Therefore, the term "processor" may refer to a processing circuit including a plurality of processing circuits, for example, any, some, or all of the above-mentioned processing circuits. The processing circuit may also perform data processing functions for inputting, outputting, and processing data, including data buffering and device control functions, such as call processing control, user interface control, etc.

[0208] Finally, it should be understood that the present application is not limited to the embodiments described above.

Claims

1. A first communication device (100), characterized in that: include: A set of antenna elements (106a, 106b...106n) configured to operate in a set of radiation modes (600a, 600b...600n); A processor (108) configured to: Acquire a first symbol constellation according to a radiation pattern (600i) in the radiation pattern set (600a, 600b ... 600n); obtaining a set of weights associated with the first symbol constellation; Acquire a second symbol constellation according to the first symbol constellation and the weight set; The set of antenna elements (106a, 106b ... 106n) is controlled according to the radiation pattern (600i) to transmit a set of information bits mapped onto the second symbol constellation.

2. The first communication device (100) according to claim 1, characterized in that Each antenna element (106n) in the set of antenna elements (106a, 106b...106n) is configured to operate in a plurality of radiation states, so that the set of antenna elements (106a, 106b...106n) operates under the set of radiation patterns (600a, 600b...600n).

3. The first communication device (100) according to claim 2, characterized in that The antenna element set (106a, 106b, ... 106n) is arranged within the range of a transmitting element (104) for transmitting radio waves, and the antenna element set (106a, 106b, ... 106n) is a radio frequency mirror set.

4. The first communication device (100) according to any one of the preceding claims, characterized in that: Obtaining the first symbol constellation includes: receiving a set of channel estimates (610a, 610b ... 610n) from a second communication device (300), wherein each channel estimate corresponds to a radiation pattern (600i) in the set of radiation patterns (600a, 600b ... 600n); The first symbol constellation is calculated based on channel estimates (610n) in the set of channel estimates (610a, 610b ... 610n).

5. The first communication device (100) according to claim 4, characterized in that Calculating the first symbol constellation comprises: The first symbol constellation is calculated based on channel estimates in the set of channel estimates and a source-based modulation.

6. The first communication device (100) according to any one of claims 1 to 3, characterized in that: Acquiring the weight set includes: receiving a set of channel estimates (610a, 610b ... 610n) from a second communication device (300), wherein each channel estimate corresponds to a radiation pattern (600i) in the set of radiation patterns (600a, 600b ... 600n); The set of weights is calculated based on the channel estimates (610n) in the set of channel estimates (610a, 610b ... 610n) and the first symbol constellation.

7. The first communication device (100) according to any one of claims 1 to 3, characterized in that: Obtaining the second symbol constellation comprises: The first symbol constellation is mapped onto the weight set to obtain the second symbol constellation.

8. The first communication device (100) according to claim 7, characterized in that Obtaining the second symbol constellation comprises: After mapping the first symbol constellation to the set of weights, power control and phase shifting are performed to obtain the second symbol constellation.

9. The first communication device (100) according to claim 8, characterized in that The second symbol constellation is any one of M-PSK or M-QAM.

10. A second communication device (300) for a communication system (500), characterized in that: The second communication device (300) is used for: Receiving a set of reference signals from a first communication device (100), wherein the set of reference signals is associated with a set of radiation patterns (600a, 600b...600n) of a set of antenna elements (106a, 106b...106n); Determining a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern (600i) in the set of radiation patterns (600a, 600b, ... 600n); calculating a first symbol constellation based on channel estimates in the set of channel estimates; sending the first symbol constellation to the first communication device (100); Calculating a set of weights based on channel estimates in the set of channel estimates and the first symbol constellation; The weight set is sent to the first communication device (100).

11. A method for a first communication device (100), characterized in that: The first communication device (100) comprises a set of antenna elements (106a, 106b ... 106n), wherein the set of antenna elements (106a, 106b ... 106n) is configured to operate under a set of radiation patterns (600a, 600b ... 600n); The method (200) comprises: Acquire (202) according to a radiation pattern (600i) in the radiation pattern set (600a, 600b ... 600n) First symbol constellation; obtaining (204) a set of weights associated with the first symbol constellation; Obtaining (206) a second symbol constellation based on the first symbol constellation and the set of weights; controlling (208) the set of antenna elements (106a, 106b ... 106n) according to the radiation pattern (600i), To send a set of information bits mapped onto the second symbol constellation.

12. A method (400) for a second communication device (300), characterized in that: The method (400) comprises: Receiving (402) a set of reference signals from a first communication device (100), wherein the set of reference signals is associated with a set of radiation patterns (600a, 600b ... 600n) of a set of antenna elements (106a, 106b ... 106n); determining (404) a set of channel estimates based on the received set of reference signals, wherein each channel estimate corresponds to a radiation pattern (600i) in the set of radiation patterns (600a, 600b ... 600n); calculating (406) a first symbol constellation based on channel estimates in the set of channel estimates; sending the first symbol constellation to the first communication device (100); Calculating a set of weights based on channel estimates in the set of channel estimates and the first symbol constellation; The weight set is sent to the first communication device (100).

13. A computer-readable storage medium for storing a computer program having a program code, characterized in that: The program code is used to perform the method according to claim 11 or 12 when the computer program is run on a computer.

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