Method and apparatus for modulation
The proposed Grass-lattice modulation technique addresses high PAPR and quantization noise issues by using uniformly distributed T-dimensional symbols, ensuring 0dB PAPR and improved demodulation efficiency with low-resolution ADCs.
Patent Information
- Application Number
- PCT/CN2024/074434
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-29
- Publication Date
- 2025-08-07
AI Technical Summary
Existing non-coherent modulation techniques, such as Grassmannian modulation, result in high peak-to-power-ratio (PAPR) performance and are not robust to quantization noise when using low-resolution analog-to-digital converters (ADCs), particularly in single-carrier systems.
A method for modulation and demodulation using a complex T-dimensional symbol with uniform element-wise distribution, specifically the proposed Grass-lattice modulation, which ensures each dimension has the same norm, achieving 0dB PAPR and improved robustness to quantization noise.
The proposed method achieves 0dB PAPR and enhanced robustness to quantization noise, particularly in single-carrier systems, while maintaining effective demodulation performance even with one-bit resolution ADCs and low sample counts.
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Figure CN2024074434_07082025_PF_FP_ABST
Abstract
Description
METHOD AND APPARATUS FOR MODULATIONTECHNICAL FIELD
[0001] Embodiments of the present application relate to the field of communications technologies, and more specifically, to a method and an apparatus for modulation.BACKGROUND
[0002] Modulation is a process of converting data into radio waves by adding information to an electronic carrier signal. Coherent modulation and non-coherent modulation are two commonly used modulation methods in the field of communications. In coherent communications where the coherent modulation is used, channel estimation is required, and the amount of overhead strongly depends on the channel variations. In non-coherent communications where the non-coherent modulation is used, channel estimation is not required, which is different from coherent communications. However, inappropriate non-coherent modulation would result in high peak-to-power-ratio performance.SUMMARY
[0003] Embodiments of the present application provide a method and an apparatus for modulation.
[0004] According to a first aspect, an embodiment of the present application provides a method for modulation, and the method could be performed by a transmitting apparatus. The method includes: modulating data based on a non-coherent modulation operation, a modulation symbol used in the non-coherent modulation operation being a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol has a same norm.
[0005] According to a second aspect, an embodiment of the present application provides a method for demodulation, and the method could be performed by a receiving apparatus. The method includes: demodulating data based on a non-coherent demodulation operation, a modulation symbol used in the non-coherent demodulation operation being a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol having a same norm.
[0006] The transmitting apparatus could modulate and transmit the data. Correspondingly, the receiving apparatus could receive and demodulate the data. For data transmission between the transmitting apparatus and the receiving apparatus, a demodulation operation performed by the receiving apparatus shall be associated with or correspond to a modulation operation performed by the transmitting apparatus. The modulation symbol used in the non-coherent modulation could also be referred to as the modulation symbol used in the non-coherent demodulation.
[0007] In an embodiment, for uplink transmission, the transmitting apparatus could be a user device or a chip in the user device, while the receiving apparatus could be a network device or a chip in the network device.
[0008] In another embodiment, for downlink transmission, the transmitting apparatus could be a network device or a chip in the network device, while the receiving apparatus could be a user device or a chip in the user device.
[0009] In still another embodiment, for side-link transmission, the transmitting apparatus could be a user device or a chip in the user device, while the receiving apparatus could be another user device or a chip in the user device.
[0010] In some embodiments, there are multiple modulation / demodulation operations, while multiple modulation symbols would be involved. The transmitting apparatus could select a modulation operation to modulate the data, and the receiving apparatus could select a demodulation operation to demodulate the data.
[0011] In order to distinguish with other modulation symbols, the modulation symbol that is a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol has a same norm is also be referred to as a first modulation symbol. A modulation operation using the first modulation symbol could also be referred to as a first modulation operation; correspondingly, a demodulation operation using the first modulation symbol could also be referred to as a first demodulation operation. The first modulation operation is associated with or corresponds to the first demodulation operation. In other words, a distribution of modulation points used in the first modulation / demodulation operation could be element-wise uniform. The transmitting apparatus used to perform the method according to the first aspect is able to modulate the data based on the first modulation operation. The receiving apparatus used to perform the method according to the second aspect is able to demodulate the data based on the first demodulation operation.
[0012] According to the above-mentioned technical solution, the distribution of modulation points used in the first modulation scheme could be element-wise uniform. It could achieve a 0 decibel (dB) peak-to-power-ratio (PAPR) in single-carrier systems, and can be performed in the presence of a one-bit resolution analog-to-digital converter (ADC) at the receiving apparatus for an arbitrary quantization threshold and the low number of samples.
[0013] With reference to the first aspect or the second aspect, in some embodiments, the method further includes: transmitting, by the receiving apparatus, first information; or receiving, by the transmitting apparatus, the first information. The first information is used to determine a modulation operation used to modulate the data.
[0014] In an embodiment, for uplink transmission, a network device could transmit information to a used device to indicate a modulation operation (e.g., the first modulation operation) for modulating the data. The used device could select a modulation operation from a plurality of modulation operations according to this information. This information could be taken as an example of the first information.
[0015] In another embodiment, for side-link transmission, a user device #1 transmits data to a user device #2. The user device #2 could transmit information to the user device #1 to indicate a modulation operation for modulating the data. This information could be taken as an example of the first information.
[0016] With reference to the first aspect or the second aspect, in some embodiments, the method further includes: transmitting, by the transmitting apparatus, second information; or receiving, by the receiving apparatus, the second information. The second information is used to determine a demodulation operation used to demodulate the data.
[0017] In an embodiment, for downlink transmission, a network device could transmit information to a used device to indicate a demodulation operation (e.g., the first demodulation operation) for demodulating the data. This information could be taken as an example of the second information.
[0018] In another embodiment, for side-link transmission, the user device #1 transmits data to the user device #2. The user device #1 could transmit information to the user device #1 to indicate a demodulation operation for demodulating the data. This information could be taken as an example of the second information.
[0019] According to the above-mentioned technical solution, a proper modulation scheme could be determined to modulate or demodulate the data from different requirements of the system.
[0020] With reference to the first aspect or the second aspect, in some embodiments, the first information includes a first parameter.
[0021] In an embodiment, the first information could indicate modulating the data based on the first modulation operation when the first parameter is a first value. In this scenario, the transmitting apparatus could use the first modulation operation to modulate the data according to the first information.
[0022] In another embodiment, since a demodulation operation performed by the receiving apparatus shall be associated with or correspond to a modulation operation performed by the transmitting apparatus, the first information could indicate that the first demodulation operation is used to demodulate the data when the first parameter is the first value. In this scenario, the transmitting apparatus could use the first modulation operation to modulate the data according to the first information.
[0023] With reference to the first aspect or the second aspect, in some embodiments, the second information includes the first parameter.
[0024] In an embodiment, the second information could indicate demodulating the data based on the first demodulation operation when the first parameter is a first value.
[0025] In another embodiment, since a demodulation operation performed by the receiving apparatus shall be associated with or correspond to a modulation operation performed by the transmitting apparatus, the second information could indicate that the first modulation operation is used to modulate the data when the first parameter is the first value. In this scenario, the receiving apparatus could use the first demodulation operation to demodulate the data according to the second information.
[0026] With reference to the first aspect or the second aspect, in some embodiments, the first information or the second information indicates one or more of: a first threshold, a second threshold, and a third threshold.
[0027] The first threshold is a threshold for the number of samples able to be processed by a first user device, and the first user device is used to modulate or demodulate the data. In an embodiment, for uplink transmission, the first user device could be a user device configured to transmit the data. In another embodiment, for downlink transmission, the first user device could be a user device configured to receive the data. In still another embodiment, for side-link transmission, the first user device could be a transmitter or the receiver.
[0028] The second threshold could be a threshold of quantization related to an ADC used at a receiver. The third threshold could be used to determine a type of the ADC used at the receiver. The type of the ADC includes a first type of ADC or a second type of ADC, and resolution of the first type of ADC is lower than resolution of the second type of ADC.
[0029] With reference to the first aspect or the second aspect, in some embodiments, the first information or the second information includes a second parameter. The second parameter indicates the ADC used at the receiver to be the first type of ADC when the second parameter is a second value; or the second parameter indicates the ADC used at the receiver to be the second type of ADC when the second parameter is a third value.
[0030] With reference to the first aspect or the second aspect, in some embodiments, first information or the second information includes a first indication to indicate a power consumption of the ADC used at the receiver.
[0031] The ADC used at the receiver is the first type of ADC when the power consumption of the ADC used at the receiver is less than the third threshold. The ADC used at the receiver is the second type of ADC when the power consumption of the ADC used at the receiver is larger than the third threshold. In possible implementations, the ADC used at the receiver is the first type of ADC when the power consumption of the ADC used at the receiver is equal to the third threshold. In possible implementations, the ADC used at the receiver is the second type of ADC when the power consumption of the ADC used at the receiver is equal to the third threshold.
[0032] In some embodiments, the first modulation operation is determined to be used to modulate the data according to the first information, when the number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold.
[0033] In some embodiments, the first modulation operation is determined to be used to modulate the data according to the first information, when the number of carriers is one, BLER performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.
[0034] In some embodiments, the first demodulation operation is determined to be used to demodulate the data according to the second information, when the number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold.
[0035] In some embodiments, the first demodulation operation is determined to be used to demodulate the data according to the second information, when the number of carriers is one, BLER performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.
[0036] With reference to the first aspect or the second aspect, in some embodiments, the method further includes: transmitting, by the receiving apparatus, third information; or receiving, by the transmitting apparatus, the third information. The third information indicates a relationship between a first element and a first vector.
[0037] With reference to the first aspect or the second aspect, in some embodiments, the method further includes: transmitting, by the transmitting apparatus, fourth information; or receiving, by the receiving apparatus, the fourth information. The fourth information indicates the relationship between the first element and the first vector.
[0038] The first element is an element of the first dimension of the first modulation symbol, and the first vector is a vector comprising each element of the last (T-1) dimension (s) of the first modulation symbol.
[0039] According to a third aspect, a transmitting apparatus is provided. The transmitting apparatus includes a function or unit configured to perform the method according to the first aspect or any one of the possible embodiments of the first aspect.
[0040] For example, the transmitting apparatus could be a network device or a chip in the network device. For another example, the transmitting apparatus could be a user device or a chip in the user device.
[0041] According to a fourth aspect, a receiving apparatus is provided. The receiving apparatus includes a function or unit configured to perform the method according to the second aspect or any one of the possible embodiments of the second aspect.
[0042] For example, the receiving apparatus could be a user device or a chip in the user device. For another example, the receiving apparatus could be a network device or a chip in the network device.
[0043] According to a fifth aspect, a system is provided. The system includes: the transmitting apparatus according to the third aspect and the receiving apparatus according to the fourth aspect.
[0044] According to a sixth aspect, an apparatus is provided. The apparatus includes at least one processor, and the at least one processor is coupled to at least one memory. The at least one memory is configured to store a computer program or one or more instructions. The at least one processor is configured to: invoke the computer program or the one or more instructions from the at least one memory and run the computer program or the one or more instructions, so that the apparatus performs the method in any one of the first aspect or the possible implementations of the first aspect, or the apparatus performs the method in any one of the second aspect or the possible implementations of the second aspect.
[0045] With reference to the sixth aspect, in some implementations of the sixth aspect, the apparatus may be a transmitting apparatus. For example, the apparatus may be a network device or a component (for example, a chip or an integrated circuit) installed in the network device. For another example, the apparatus may be a user device or a component (for example, a chip or an integrated circuit) installed in the user device.
[0046] With reference to the sixth aspect, in some implementations of the sixth aspect, the apparatus may be a receiving apparatus. For example, the apparatus may be a user device or a component (for example, a chip or an integrated circuit) installed in the user device. For another example, the apparatus may be a network device or a component (for example, a chip or an integrated circuit) installed in the network device.
[0047] According to a seventh aspect, an apparatus is provided. The apparatus includes a processor and a communications interface. The processor is connected to the communications interface. The processor is configured to execute one or more instructions, and the communications interface is configured to communicate with other network elements under the control of the processor. The processor is enabled to perform the method according to the first aspect or any one of the possible embodiments of the first aspect, or the second aspect or any one of the possible embodiments of the second aspect.
[0048] According to an eighth aspect, a computer storage medium is provided. The computer storage medium stores program code, and the program code is used to execute one or more instructions for the method according to the first aspect or any one of the possible embodiments of the first aspect, or the second aspect or any one of the possible embodiments of the second aspect.
[0049] According to a ninth aspect, this application provides a computer program product including one or more instructions, where when the computer program product runs on a computer, the computer performs the method according to the first aspect or any one of the possible embodiments of the first aspect, or the second aspect or any one of the possible embodiments of the second aspect.DESCRIPTION OF DRAWINGS
[0050] One or more embodiments are exemplarily described by corresponding accompanying drawings, and these exemplary illustrations and accompanying drawings constitute no limitation on the embodiments. Elements with the same reference numerals in the accompanying drawings are illustrated as similar elements, and the drawings are not limited to scale, in which:
[0051] FIG. 1 is a schematic diagram of an example of coherent communications with DMRS symbols.
[0052] FIG. 2 is a schematic diagram of an example of non-coherent communications without DRMS symbols.
[0053] FIG. 3 is a schematic diagram of a method for determining Grass-lattice modulation.
[0054] FIG. 4 is a schematic flowchart of a method for communication according to some embodiments of the present application.
[0055] FIG. 5 is a schematic diagram of a comparison of PAPR performance between two different non-coherent modulations.
[0056] FIG. 6 is a schematic diagram of a comparison of BLER performance between two different non-coherent modulations.
[0057] FIG. 7 is a schematic diagram of an example of a first parameter.
[0058] FIG. 8 is a schematic flowchart of a method 800 according to some embodiments of the present application.
[0059] FIG. 9 is a schematic flowchart of a method 900 according to some embodiments of the present application.
[0060] FIGS. 10-12 are schematic block diagrams of possible devices according to embodiments of this application.DESCRIPTION OF EMBODIMENTS
[0061] In order to understand features and technical contents of embodiments of the present disclosure in detail, implementations of the embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings, and the attached drawings are only for reference and illustration purposes, and are not intended to limit the embodiments of the present disclosure. In the following technical descriptions, for ease of explanation, numerous details are set forth to provide a thorough understanding of the disclosed embodiments. One or more embodiments, however, may be practiced without these details. In other cases, well-known structures and apparatuses may be shown simplified in order to simplify the drawings.
[0062] Related technologies and concepts are introduced here firstly in order to better understand the technical solution proposed by the present application.
[0063] (1) Block fading channel
[0064] A block fading channel is a channel model used in signal processing. In this model, channel coefficients are constant during the coherent time of the channel and then suddenly experience abrupt changes over the next block. A size of the block is known as channel coherence time. In other words, a block of symbols during the coherent time is exposed to a same channel gain.
[0065] (2) Unitary matrix
[0066] A unitary matrix is a complex matrix. A product of a unitary matrix and its conjugate transpose is equal to an identity matrix. The conjugate transpose of a unitary matrix is also its inverse. For a unitary matrix, its columns are orthogonal unit vectors which represent the subspaces that those vectors lie in.
[0067] (3) Tall unitary matrix
[0068] For a tall unitary matrix, its columns are orthogonal unit vectors which represent the subspaces that those vectors lie in, and the number of rows is greater than the number of columns.
[0069] (4) Manifold
[0070] A manifold is a topological space that is locally Euclidean. In other words, a manifold is a differentiable surface that resembles Euclidian space in the neighborhood of each point. For example, any object that is nearly "flat" on small scales could be considered as a manifold.
[0071] (5) Coherent communication and non-coherent communication
[0072] In coherent communications, coherent modulation is used and channel estimation is required.
[0073] For illustrative purposes, let M denote the number of transmit antennas, N denote the number of receive antennas, and T be the channel coherence time.
[0074] In possible implementations, a received signal could be represented by a matrix Y of size T×N, correspondingly, the transmitted message could be represented by a matrix X of size T×M . A relationship between the received signal and the transmitted message could be represented by the following expression. Y=XH+w (1)
[0075] Here, the channel with coherent time is represented by a matrix H of size M×N, and the noise is represented by a matrix w of size T×N.
[0076] In coherent communications, in order to detect X, H could be first estimated through demodulation reference signals (DMRS) .
[0077] In an embodiment, FIG. 1 is an example of the coherent communication with DMRS symbols for channel estimation. A square in FIG. 1 could represent a symbol, such as an orthogonal frequency division multiplexing (OFDM) symbol. In FIG. 1, a time-axis could represent the OFDM symbols transmitted over the time domain, and a frequency-axis could represent the OFDM subcarriers transmitted over the frequency domain. As shown in FIG. 1, some OFDM symbols are dedicated to DMRS. In other words, different time and frequency are dedicated to DMRS symbols. In some possible implementations, DMRS symbols could be used to transmit useful information.
[0078] Non-coherent modulation, such as Grassmannian modulation, is used in non-coherent communications, which is different from coherent communications. Non-coherent modulation is shown to be a good candidate in some scenarios.
[0079] In possible implementations, over block-fading channels, at high signal-to-noise ratios (SNRs) when the channel coherence time is greater than the number of transmit and receive antennas, the channel capacity could be achieved when the information is carried by tall unitary matrices. The set of unique subspaces constitutes a geometric object which is known as a Grassmannian manifold. In other words, the Grassmannian manifold can be represented by a set of tall unitary matrices that span unique subspaces. Points in the Grassmannian modulation are taken from the Grassmannian manifold and are good candidates for communications over block-fading channels. The following embodiments are illustrated by assuming that Grassmannian modulation is used in non-coherent communications, and they are also applicable for non-coherent communications with other non-coherent modulations.
[0080] In possible implementations, in non-coherent communications with Grassmannian modulation, at high SNRs when the noise is very small, the following relationship holds. [XH] = [X] (2)
[0081] Here, [·] represents a projective class. Each Grassmannian constellation point represents basis that spans a particular subspace, and when the basis is transmitted over the channel, the basis could be scaled and rotated but the subspace spanned by the basis is retained.
[0082] For illustrative purposes, FIG. 2 is an example of non-coherent communications without DMRS symbols. As shown in FIG. 2, a square in FIG. 2 could represent an OFDM symbol. In non-coherent communications, it is not necessary to dedicate OFDM symbols to DMRS, which is different from FIG. 1.
[0083] Technical terms mentioned above are not limited to the specific example names presented herein; these terms or the concepts referred to by these terms may also be known by other names.
[0084] There are different techniques to design non-coherent modulations. For illustrative purposes, the Grassmannian modulation is taken as an example of the non-coherent modulation to illustrate design techniques. In an example, unstructured Grassmannian modulation design techniques could be designed based on the numerical optimization methods. In another example, structured Grassmannian modulation design techniques could be designed based on algebraic methods. The unstructured Grassmannian modulation design techniques can use direct optimization methods, and offer better performance compared with their structured counterparts. However, the structured Grassmannian modulation design techniques are easier to be labeled and detected.
[0085] In one embodiment, Grass-lattice modulation, a type of structured Grassmannian modulation, is taken as an example of the non-coherent modulation. An example for determining Grass-lattice modulation will be described in combination with FIG. 3.
[0086] FIG. 3 is a schematic diagram of a method for determining a Grass-lattice modulation. The method could include steps S301 to S304.
[0087] At S301, generate points on a unit cube.
[0088] Let T denote the coherence time of the channel, and B denote the number of bits per real components. The number of the points could be 2 (T-1) . Each one of 2 (T-1) uniformly distributed points, represented by a1, b1, …, aT-1, bT-1, could be chosen randomly from the regular lattice xp. Here, xp could be represented by the following expression.
[0089] Here, the value of α (α>0) determines the length of the lattice used for each real component in expression (3) , and can be optimized to minimize the error performance.
[0090] In an example, for B=1, the value of p could be 0 or 1. In this scenario, x0=α and x1=-α. Each of a1, b1, …, aT-1, bT-1 could be taken randomly from any one of x0 and x1. In other words, a1 could be x0 or x1, b1 could be x0 or x1, and so on.
[0091] In another example, for B=2, the value of p could be 0, 1, 2 or 3. In this scenario, any one of x0, x1, x2, and x3 could be determined based on expression (3) . Each of a1, b1, …, aT-1, bT-1 could be taken randomly from any one of x0, x1, x2, and x3. In possible implementations, B could be other values.
[0092] At S302, compute a vector z, isotopically distributed as
[0093] Here, represents a complex normal distribution, and IT-1 represents a T-1 dimensional identity matrix. Based on the 2 (T-1) uniformly distributed points, each element of z could be determined by the following expression. zk=F-1 (ak) +jF-1 (bk) , k=1, …, T-1 (4)
[0094] Here, zk denotes each element of z, and F (x) denotes the cumulative distribution function (CDF) of where represents a normal distribution with a mean of 0 and a variance of 1 / 2. z is a T-1 dimensional vector.
[0095] At S303, compute a vector w, uniformly distributed in a unit ball.
[0096] The vector w could be determined by the following expression. w=zfT-1 (‖z‖) (5)
[0097] Here,
[0098] At S304, output Grass-lattice modulation points that are uniformly distributed on a Grassmannian manifold.
[0099] A Grass-lattice modulation point could be represented by a vector x. The vector x could be determined by the following expression.
[0100] Here, w is a T-1 dimensional vector, x is a T-dimensional vector, and is a scalar.
[0101] The cardinality of the Grass-lattice modulation is i.e., 2B (T-1) bits are carried over T complex dimensions. For example, for B=1 and T=2, w and z are 1-dimentional vectors. In this scenario, a1 and b1 could be randomly taken from x0 or x1, respectively. Based on the values of a1 and b1, there are 4 possible values for z and x, respectively.
[0102] Traditionally, Grassmannian modulations are designed to optimize the error performance. In order to optimize the error performance, the modulation points should be uniformly distributed on the Grassmannian manifold. However, this strategy makes the points generally element-wise non-uniform. For example, the first element of x is while other elements of x are elements of w. It would result in high PAPR performance, especially in single carrier systems. As such, the Grassmannian modulations mentioned above are not in general good candidates for coverage-limited scenarios.
[0103] In addition, the Grassmannian modulations mentioned above are not robust to the quantization noise when used along with the low-resolution analog-to-digital converters (ADCs) .
[0104] With the problem identified above, how to achieve low PAPR performance by using non-coherent modulation operation is to be solved. In the following, the communication method provided in this application will be described in combination with FIG. 4.
[0105] FIG. 4 illustrates a flowchart of a method 400 for communicating according to some embodiments of the present application. The method 400 shown in FIG. 4 includes step S410 to S430.
[0106] At S410, a transmitting apparatus modulates data.
[0107] A transmitting apparatus configured to transmit the data could modulate the data. Correspondingly, a receiving apparatus configured to receive the data could demodulate the data. For example, the transmitting apparatus could be a user device or a chip in the user device; correspondingly, the receiving apparatus could be a network device or a chip in the network device. For another example, the transmitting apparatus could be a network device or a chip in the network device. Correspondingly, the receiving apparatus could be a user device or a chip in the user device.
[0108] The network device can be a base station (BS) , a base transceiver station (BTS) , a radio base station, a network node, a device on the network side, a transmit / receive node, a Node B, an evolved NodeB (eNodeB or eNB) , a Home eNodeB, a next generation NodeB (gNB) , a transmission point (TP) , a site controller, an access point (AP) , a wireless router, a relay station, a terrestrial node, a terrestrial network device, a terrestrial base station, a base band unit (BBU) , a remote radio unit (RRU) , an active antenna unit (AAU) , a remote radio head (RRH) , a central unit (CU) , a distribute unit (DU) , a positioning node, or an apparatus (e.g., a communication module, a modem, or a chip) in the foregoing devices, among other possibilities.
[0109] The user device may include such devices (or may be referred to) as a user equipment (UE) , a wireless transmit / receive unit (WTRU) , a mobile station, a fixed or mobile subscriber unit, a cellular telephone, a station (STA) , a machine type communication (MTC) device, a personal digital assistant (PDA) , a smartphone, a laptop, a computer, a tablet, a wireless sensor, a consumer electronics device, a smart book, a vehicle, a car, a truck, a bus, a train, an internet of things (IoT) device, an industrial device, or an apparatus (e.g., a communication module, a modem, or a chip) in the foregoing devices, among other possibilities.
[0110] In some implementations, the transmitting apparatus modulates data based on a non-coherent modulation operation. A modulation symbol used in the non-coherent modulation operation is a complex T-dimensional symbol, and each dimension of the complex T-dimensional symbol having a same norm. Correspondingly, the receiving apparatus receives the data and demodulates the data based on a non-coherent demodulation operation.
[0111] The non-coherent demodulation operation shall be associated with or correspond to the non-coherent modulation operation. The modulation symbol used in the non-coherent modulation operation could also be referred to as a modulation symbol used in the non-coherent demodulation operation.
[0112] In some embodiments, there may be other modulation operations could be used to modulate data. In order to distinguish with other modulation operations, the modulation operation mentioned above is referred to as a first modulation operation, and a demodulation operation associated with or corresponding to the first modulation operation could be referred to as a first demodulation operation. A modulation symbol used in first modulation operation / first demodulation operation is referred to as a first modulation symbol. In other words, the first modulation symbol is a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol having a same norm.
[0113] The “first modulation operation” , “first demodulation operation” and “first modulation symbol” are only named for differentiation and does not limit the scope of protection of the embodiments of this application. Similarly, a “second modulation operation” , and a “second modulation symbol” , etc. in the following description are also only named for differentiation and do not limit the scope of protection of the embodiments of this application, and this will not be repeated below.
[0114] In an embodiment, there is another non-coherent modulation operation, e.g., a second modulation operation. Correspondingly, there is a second demodulation operation associated with the second modulation operation. A modulation symbol used in second modulation operation is also referred to as a second modulation symbol. The second modulation symbol is a complex T-dimensional symbol and a norm of at least one dimension of the second modulation symbol is different from a norm of another dimension of the second modulation symbol, which is different from the first modulation symbol. In other words, the distribution of modulation points in the first modulation operation could be element-wise uniform. The distribution of modulation points in the second modulation operation could be element-wise non-uniform. For example, a modulation operation mentioned in method 300 could be considered as an example of the second modulation operation. In this scenario, the vector x determined by expression (7) could be taken as an example of the second modulation symbol.
[0115] For illustrative purposes, the Grass-lattice modulation mentioned in method 300 is taken as an example of the second modulation operation. Moreover, the proposed Grass-lattice modulation of the present application is taken as an example of the first modulation operation. The following embodiments would illustrate the distribution of modulation points in the first modulation operation and the second modulation operation.
[0116] A binary digit (e.g., 0 or 1) could be taken as an input value of a Grassmannian modulation mapper, and the Grassmannian modulation mapper could output complex T-dimensional modulation symbols.
[0117] Let nbits represent the number of bits carried over T complex dimensions. For the Grass-lattice modulation mentioned in method 300, nbits=2B (T-1) . Let decbits denote the decimal representation of each nbits-tuplets of bits, where A set of modulation points in the Grass-lattice modulation mentioned in method 300, could be represented by a matrix C of size In other words, C has rows and T columns, where each of its rows denotes a T-dimensional vector determined based on expression (7) . For a given combination of T, B and α, the different value of p would result in different xp in expression (3) . Choosing different combinations of p in expression (3) would result in different zk in expression (4) and different x in expression (7) . The modulation symbol corresponding to each nbits-tuplets of input bits is then
[0118] d=Cdecbits+1, (8)
[0119] where Cdecbits+1 denotes the (dechits+1) th row of C.
[0120] In an example, for B=1, T=2 and α=0.19, modulation points in the Grass-lattice modulation mentioned in method 300 could be represented by last T columns of Table 1. The last T columns of each row in Table 1 can represent a possible value of x determined based on expression (7) . In other words, Table 1 illustrates 4 possible values of x, for B=1, T=2 and α=0.19. In this scenario, a possible value of x could be taken as an example of a modulation point in the second modulation operation.
[0121] Table 1: The modulation points in Grass-lattice modulation mentioned in method 300, for T=2, B=1 and α=0.19, where A0≠A1.
[0122] In another example, for B=1, T=3 and α=0.19, modulation points in the Grass-lattice modulation mentioned in method 300 could be represented by last T columns of Table 2. The last T-1 columns of each row in Table 2 can represent a possible value of w determined based on expression (6) . Table 2 illustrates 16 possible values of x, for B=1, T=3 and α=0.19.
[0123] Table 2: The modulation points in Grass-lattice modulation mentioned in method 300, for B=1, T=3 and α=0.19.
[0124] In Table 1 and Table 2, A0 represents the power of the first dimension of x, and A1 represents the power of each of other dimensions of x. In other words, when B=1, for each possible value of x determined based on expression (7) , a norm of its first dimension is different from a norm of any one of other dimensions. It is noted that the values of A0 and A1 in Table 1 could be different from that in Table 2.
[0125] According to any example in Table 1 and Table 2, the distribution of modulation points in the Grass-lattice modulation mentioned in method 300 are element-wise non-uniform, due to A0≠A1 . It would result in high PAPR performance in single carrier systems. Moreover, the Grass-lattice modulation mentioned in method 300 cannot be performed in the presence of one-bit resolution ADCs at the receiver for an arbitrary quantization threshold and the low number of samples.
[0126] In possible implementations, when B is other values, a norm of at least one dimension of x is different from a norm of another dimension of x. In other words, when B is other values, x would also be element-wise non-uniform.
[0127] The following embodiment would involve the proposed Grass-lattice modulation of the present application. Correspondingly, a modulation symbol used in the proposed Grass-lattice modulation could be represented by a vector xproposed. xproposed could be taken as an example of the first modulation symbol. Similarly to x, xproposed could be a T-dimensional vector. xproposed could be determined by the following expression.
[0128] Here, wtopt represents the element w that results in minimum error performance. The first dimension of xproposed would be the same for different nbits-tuplets of input bits.
[0129] It would result in an element-wise uniform xproposed based on expression (9) , which could achieve a 0dB PAPR and make it more robust to the quantization noise, especially at the low-number of samples. The cardinality of the proposed Grass-lattice modulation could be i.e., 2B (T-1) bits are carried over T complex dimensions.
[0130] A set of modulation points in the proposed Grass-lattice modulation could be represented by a matrix Cproposed of size In other words, Cproposed has rows and T columns, where each of its rows denotes a T-dimensional vector determined based on expression (9) . For a given combination of T, B and α, the different value of p would result in different xp in expression (3) . Choosing different combinations of p in expression (3) would result in different zk in expression (4) and different xproposed in expression (9) . The modulation symbol corresponding to each nbits-tuplets of input bits is then
[0131] where denotes the (dechits+1) th row of Cproposed.
[0132] In an example, for B=1, T=2 and α=0.19, modulation points in the proposed Grass-lattice modulation could be represented by last T columns of Table 3. The last T columns of each row in Table 3 can represent a possible value of xproposed determined based on expression (9) . In other words, Table 3 illustrates 4 possible values of xproposed, for B=1, T=2 and α=0.19. In this scenario, a possible value of xproposed could be taken as an example of a modulation point in the first modulation operation.
[0133] Table 3: The modulation points in the proposed Grass-lattice modulation for T=2, B=1 and α=0.19.
[0134] In another example, for B=1, T=3 and α=0.19, modulation points in the proposed Grass-lattice modulation of the present application could be represented by last T columns of Table 4. In this scenario, Table 4 illustrates 16 possible values of xproposed, for B=1, T=3 and α=0.19. The value of A in Table 4 could be different from that in Table 3.
[0135] Table 4: The modulation points in the proposed Grass-lattice modulation for B=1, T=3 and α=0.19.
[0136] According to any example in Table 3 and Table 4, when B=1, the first dimension of Cproposed has the same norm as the other subsequent dimensions and is the same for all the nbits-tuplets combinations. In other words, the distribution of modulation points in the proposed Grass-lattice modulation are element-wise uniform.
[0137] In possible implementations, for any one example in Table 3 or Table 4, the modulation power is determined based on A. Moreover, when the modulation power is normalized, A=1.
[0138] In possible implementations, when B is other values, each dimension of xproposed would have a same norm. In other words, xproposed still be element-wise uniform.
[0139] According to the technical solution mentioned above, the distribution of modulation points in the first modulation operation could be element-wise uniform. It could achieve a 0dB PAPR in single-carrier systems, and can be performed in the presence of one-bit resolution ADCs at the receiver for an arbitrary quantization threshold and the low number of samples.
[0140] Moreover, in the following, the PAPR performance and block error rate (BLER) performance of the first modulation operation and the second modulation operation will be described in combination with FIG. 5 and FIG. 6, respectively. In FIG. 5 and FIG. 6, the Grass-lattice modulation mentioned in method 300 is taken as an example of the second modulation operation, and the proposed Grass-lattice modulation is taken as an example of the first modulation operation.
[0141] FIG. 5 illustrates a comparison of PAPR performance between two different modulation operations. In FIG. 5, the comparison is made over 42 OFDM symbols with each OFDM symbol having a single carrier, and the transport block size (TBS) of 35 is considered.
[0142] In FIG. 5, the PAPR performance of the real part, the imaginary part and the total PAPR of the first modulation operation and that of second modulation operation, are illustrated for T=6, B=1 and α=0.17. The PAPR performance of the real part, the imaginary part and the total PAPR of the first modulation operation could be represented by Curve #1 to #3 in FIG. 5, respectively. Curve #4 to #6 in FIG. 5 represent the PAPR performance of the real part, the imaginary part and the total PAPR of the second modulation operation, respectively.
[0143] As shown in FIG. 5, the first modulation operation outperforms the second modulation operation in terms of the PAPR performance of the real part, the imaginary part, and the total PAPR. In particular, the first modulation operation achieves a 0dB PAPR in terms of its total PAPR, and beats the second modulation operation by 1.8dB at the target complementary cumulative distribution function (CCDF) of 10-2.
[0144] FIG. 6 illustrates a comparison of BLER performance between two different modulation operations. In FIG. 6, the comparison is made over 42 OFDM symbols with a single carrier for each OFDM symbol, and TBS of 35 is considered with the low-density parity check (LDPC) code of rate 0.5.
[0145] In FIG. 6, the BLER performance of the first modulation operation and that of the second modulation operation are illustrated for T=6, B=1 and α=0.17, when a 1-bit ADC is used at the receiver for different quantization thresholds (represented by “thresh” in FIG. 6) and different number of samples (represented by nS) . In FIG. 6, the BLER performance of the second modulation operation in different scenarios could be represented by Curve #1 to #5, respectively. In FIG. 6, Curve #6 to #10 could represent the BLER performance of the first modulation operation in different scenarios, respectively.
[0146] Referring to Curve #1 in FIG. 6, when the quantization threshold is set to 0 and nS=4, the second modulation operation does not work and produce unacceptable error performance. However, according to the Curve #6 in FIG. 6, the first modulation operation would result in acceptable error performance in the same condition.
[0147] As shown in FIG. 6, both the quantization threshold and the number of samples have a significant impact on the performance of the Grass-lattice-based modulations, such as the Grass-lattice modulation mentioned in method 300 and the proposed Grass-lattice modulation.
[0148] Moreover, as shown in FIG. 6, by using a high enough number of samples (e.g., nS=2048) and a 0 threshold for the 1-bit ADC, the first modulation operation is only away by 0.66dB from the second modulation operation at the target BLER of 10-1, but gains in terms of PAPR by 1.8dB, as shown in FIG. 5.
[0149] At S420, the transmitting apparatus transmits the data; correspondingly, a receiving apparatus receives the data.
[0150] At S430, the receiving apparatus demodulates the data.
[0151] In an example, for uplink transmission, a user device could modulate and transmit data to a network device. The network device could demodulate the data. In another example, for downlink transmission, a network device could modulate and transmit data to a user device. The user device could demodulate the data. In still another example, for side-link transmission, a user device could modulate and transmit data to another user device that receives and demodulate the data.
[0152] The receiving apparatus shall demodulate the data based on a demodulation operation associated with or corresponding to a modulation operation used to modulate the data. For example, the first demodulation operation shall be used to demodulate the data when the first modulation operation is used to modulate the data. For another example, the second demodulation operation shall be used to demodulate the data when the second modulation operation is used to modulate the data.
[0153] In some implementations, before S410, the receiving apparatus shall indicate the transmitting apparatus about configurations for modulation or demodulation before the transmitting apparatus modulates the data. That is, the transmitting apparatus and the receiving apparatus may perform the following at S440.
[0154] Optionally, at S440, the receiving apparatus transmits first information. Correspondingly, the transmitting apparatus receives the first information.
[0155] The first information is used to determine a modulation operation used to modulate the data. In an embodiment, for uplink transmission, a network device transmits information to a user device to indicate a modulation operation used to modulate data. The user device could determine a modulation operation from a plurality of modulation operations based on this information. In this scenario, this information could be taken as an example of the first information.
[0156] In some embodiments, the first information includes a first parameter. When the first parameter is a first value, the first information indicates the first modulation operation to be the modulation operation used to modulate the data. When the first parameter is another value (e.g., a fourth value) , the first information indicates the second modulation operation to be the modulation operation used to modulate the data. The first value could be an arbitrary value, such as 0, 1 or other values. The fourth value could be an arbitrary value and different from the first value.
[0157] In an embodiment, the first parameter could have a binary value. For example, the first value is 1 and the fourth value is 0. For another example, the first value is 0 and the fourth value is 1.
[0158] For illustrative purpose, FIG. 7 illustrates an example of the first parameter. In FIG. 7, an indication parameter is used to indicate whether the modulation operation used to modulate the data is the first modulation operation. As shown in FIG. 7, when the first modulation operation could be used to modulate the data. Otherwise, the second modulation operation could be used. In this embodiment, could be taken as an example of the first parameter.
[0159] In some embodiments, the first information could indicate one or more of: a first threshold, a second threshold, and a third threshold. The first threshold could be a threshold for the number of samples able to be processed by a first user device. The second threshold is a threshold of quantization related to an ADC used at a Rx. The third threshold is used to determine a type of the ADC used at the Rx. The type of the ADC includes a first type of ADC or a second type of ADC. Resolution of the first type of ADC is lower than resolution of the second type of ADC.
[0160] The first user device could be a user device used to modulate or demodulate the data. In an example, for uplink transmission, a user device could modulate and transmit data to a network device. In this scenario, the user device that modulates and transmits the data could be taken as an example of the first user device. In another example, for downlink transmission, a network device could modulate and transmit data to a user device; correspondingly, the user device could receive and demodulate the data. In this scenario, the user device that receives and transmits the data could be taken as an example of the first user device. In still another example, for side-link transmission, a user device could modulate and transmit data to another user device that receives and demodulate the data. In this scenario, the first user device could be any one of the two user devices.
[0161] The first type of ADC could be referred to as a low-resolution ADC. Correspondingly, the second type of ADC could be referred to as a high-resolution ADC.
[0162] In some embodiments, for the low-resolution ADC, a quantization level / threshold could be adopted. For example, when a one-bit ADC is used at the Rx, the signal could be mapped to two levels (e.g., a first level and a second level) based on the quantization threshold. The value of the quantization threshold could have a significant impact on the performance of the system. In an example, the quantization threshold could be 0. In other words, when the signal value is greater than 0, it would be mapped to the first level; or when the signal value is less than 0, it would be mapped to the second level. The quantization threshold could be taken as an example of the second threshold.
[0163] The third threshold could be a threshold for power consumption of the ADC used at the Rx. When the power consumption of the ADC used at the Rx is less than or equal to the third threshold, the ADC used at the Rx is the first type of ADC. When the power consumption of the ADC used at the Rx is larger than the third threshold, the ADC used at the Rx is the second type of ADC. For example, a transmission and receiving point (TRP) could transmit the third threshold to the user device, and the user device could determine the type of ADC used at the Rx.
[0164] In an embodiment, the first type of ADC could be a one-bit ADC. In other words, the third threshold could be used to determine whether the ADC used at the Rx is a one-bit ADC.
[0165] In another embodiment, the first information could include a first indication to indicate a power consumption of the ADC used at the receiver.
[0166] In possible implementations, there may be other methods to indicate the type of the ADC used at the Rx. For example, the first information could include a second parameter. When the second parameter is a second value, it indicates the ADC used at the Rx to be the first type of ADC. When the second parameter is a third value, it indicates the ADC used at the Rx to be the second type of ADC. The second value could be an arbitrary value, such as 0, 1 or other values. The third value could be an arbitrary value and different from the second value.
[0167] In some embodiments, the second parameter could have a binary value. For example, the second value is 1 and the third value is 0. In another example, the second value is 0 and the third value is 1.
[0168] For illustrative purpose, the following embodiments are illustrated by assuming that the receiving apparatus transmits first information to the transmitting apparatus. In an embodiment, the first non-coherent modulation operation is determined to be used to modulate the data, when the number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold. In another embodiment, the first non-coherent modulation operation is determined to be used to modulate the data, when the number of carriers is one, BLER performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.
[0169] In some implementations, before S430, the transmitting apparatus shall indicate the receiving apparatus about configurations for modulation or demodulation before the receiving apparatus demodulates the data. That is, the transmitting apparatus and the receiving apparatus may perform the following at S450.
[0170] Optionally, at S450, the transmitting apparatus transmits second information. Correspondingly, the receiving apparatus receives the second information.
[0171] The second information is used to determine a demodulation operation used to demodulate the data. In an embodiment, for downlink transmission, a network device transmits information to a user device to indicate a demodulation operation used to demodulate data. The user device could determine a demodulation operation from a plurality of demodulation operations based on this information. In this scenario, this information could be taken as an example of the second information.
[0172] Since the demodulation operation performed by the receiving apparatus shall be associated with or correspond to the modulation operation performed by the transmitting apparatus, information indicating the demodulation operation used at the receiving apparatus could indicate the modulation operation used at the transmitting apparatus.
[0173] In some embodiments, the second information could include the first parameter. For example, when the first parameter is a first value, the second information could indicate the receiving apparatus to demodulate the data based on the first demodulation operation. In other words, the second information could indicate the receiving apparatus that the first modulation operation is used to modulate the data by the transmitting apparatus, when the first parameter is a first value. Therefore, the receiving apparatus could perform the first demodulation operation to demodulate the data based on the second information.
[0174] In some embodiments, the second information indicates one or more of: the first threshold, the second threshold, and the third threshold.
[0175] In some embodiments, the second information include the second parameter.
[0176] For illustrative purpose, the following embodiments are illustrated by assuming that the transmitting apparatus transmits the second information to the receiving apparatus. The second information indicates one or more of: the first threshold, the second threshold, and the third threshold. In an embodiment, the first non-coherent demodulation operation is determined to be used to demodulate the data, when the number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold. In another embodiment, the first non-coherent demodulation operation is determined to be used to demodulate the data, when the number of carriers is one, BLER performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.
[0177] For illustrative purposes, in a side-link scenario, a user device #1 could modulate and transmit data to a user device #2. Correspondingly, the user device #2 could receive and demodulate the data. In an embodiment, the user device #2 could transmit the first information; correspondingly, the user device #1 could receive the first information. The user device #1 could determine a modulation operation used to modulate the data based on the first information. In another embodiment, the user device #1 could transmit the second information; correspondingly, the user device #2 could receive the second information. The user device #2 could determine a demodulation operation used to demodulate the data based on the second information.
[0178] In some implementations, before S410, the receiving apparatus shall indicate the transmitting apparatus about a relationship between a first element of the first modulation symbol and a first vector. That is, the transmitting apparatus and the receiving apparatus may perform the following at S460.
[0179] Optionally, at S460, the receiving apparatus transmits third information. Correspondingly, the transmitting apparatus receives the third information.
[0180] The first element is an element of the first dimension of the first modulation symbol. The first vector is a vector including each element of the last (T-1) dimension (s) of the complex T-dimensional symbol.
[0181] In an embodiment, a scaling parameter σ could be used to determine wtopt in expression (9) . For example, xproposed could be represented by the following expression.
[0182] In this scenario, σ could indicate the relationship between a first element and the first vector. For uplink transmission, a TRP could transmit information including σ to a user device. This information could be taken as an example of the third information.
[0183] In some implementations, before S430, the transmitting apparatus shall indicate the receiving apparatus about a relationship between a first element of the first modulation symbol and a first vector. That is, the transmitting apparatus and the receiving apparatus may perform the following at S470.
[0184] Optionally, at S470, the transmitting apparatus transmits fourth information. Correspondingly, the receiving apparatus receives the fourth information.
[0185] In an embodiment, σ mentioned above could be used. For downlink transmission, a TRP could transmit information including σ to a user device. In this scenario, the information could be taken as an example of the fourth information.
[0186] For ease of understanding of this application, in the following, an example for determining a modulation operation used to modulate data will be described in combination with FIG. 8.
[0187] For example, FIG. 8 is a schematic flowchart of a method 800 according to some embodiments of the present application. The method 800 shown in FIG. 8 illustrates how to determine a modulation operation used to modulate the data based on the first information. The method could include steps S801 to S806.
[0188] S801, obtain first information.
[0189] In some embodiments, the first information could indicate but not be limited at least one of:
[0190] 1) Number of carriers
[0191] As mentioned above, the proposed Grass-lattice modulation could achieve a 0dB PAPR in single-carrier systems. It shows advantage over the traditional modulation operation over single-carrier systems, i.e., narrow band scenarios.
[0192] 2) Power consumption at the receiver
[0193] The power consumption at the receiver could indicate whether a low-resolution ADC is used at the Rx. The low-resolution ADC could be considered as the first type of ADC. Correspondingly, a higher-resolution ADC could be considered as the second type of ADC.
[0194] In an embodiment, as shown in FIG. 8, a power indication parameter β is adopted to indicate whether a low-resolution ADC is used at the Rx. For example, β could be a binary parameter. When β=1, it indicates that a low-resolution ADC is used at the Rx. β could be taken as an example of the second parameter mentioned in the method 400.
[0195] In another embodiment, as shown in FIG. 8, a power factor threshold (represented by ρth ) is adopted to determine whether a low-resolution ADC is used at the Rx. A power factor of the receiver (represented by ρ) is adopted to indicate power consumption of the ADC used at the Rx. For example, when ρ<ρth, it could indicate that a low-resolution ADC is used at the Rx. ρth could be known to the user device. In another example, when ρ>ρth, power consumption at the receiver is not an issue. In this embodiment, ρth could be taken as an example of the third threshold mentioned in the method 400 and ρ could be taken as an example of the first indication mentioned in the method 400.
[0196] 3) Number of samples
[0197] In possible implementations, the first information could include the threshold number of samples nSth. nSth could be taken as an example of the first threshold mentioned in the method 400.
[0198] In some embodiments, let nS denote the minimum number of samples that the user device can process. For example, when nS<nSth , the first modulation operation could be used. For another example, when nS≥nSth and the BLER performance is a constraint, the second modulation operation could be used.
[0199] 4) Quantization threshold
[0200] The first information could include an optimum value for the quantization threshold, which could be taken as an example of the second threshold mentioned in the method 400. For example, when the user device does not obtain the optimum value for the quantization threshold, the quantization threshold could be set to a default value in the case of the one-bit ADC. The default value could be 0.
[0201] At S802, determine whether the number of carriers is greater than 1.
[0202] When the number of carriers is not greater than 1, the step S803 is performed, otherwise step S806 is performed
[0203] At S803, determine whether the power consumption at the receiver and the number of samples meet the preset conditions.
[0204] When ρ<ρth (or β=1) and nS<nSth, the step S805 is performed. Otherwise, the step S804 is performed.
[0205] At S804, determine whether the BLER performance is a constraint.
[0206] When ρ≥ρth (or β=0 ) or nS≥nSth , and the BLER performance is not a constraint, the step S805 is performed. Otherwise, the step S806 is performed.
[0207] At S805, determine that the first modulation operation is used to modulate the data.
[0208] At S806, determine that the second modulation operation is used to modulate the data.
[0209] In an embodiment, when the UE does not receive any one of ρth (or β) , nSth and any indication on the BLER performance constraint, the step S806 could be performed.
[0210] FIG. 9 shows a schematic flowchart of a method 900 according to an embodiment of the present application. For uplink, the method could include steps S901 and S902. For downlink, the method could include steps S901 and S903.
[0211] At S901, the TRP transmits configuration parameters. Correspondingly, the UE receives the configuration parameters.
[0212] In possible implementations, the configuration parameters could include at least one of the following: channel coherence time (represented by T) , the number of bits per real dimension (represented by B) , a value of α, a power factor threshold (represented by ρth or the power indication parameter represented by β ) , the threshold number of samples (represented by nSth) , an indication of whether BLER performance is a constraint or not, an optimum value of the quantization threshold for 1-bit ADC, and an indication parameter to indicate the modulation / demodulation operation (represented by ) .
[0213] In some embodiments, the configuration parameters can be conveyed to the UE semi-statically, e.g., through radio resource control (RRC) , or dynamically, e.g., through downlink control information (DCI) .
[0214] For uplink transmission, the UE could determine a modulation operation used to modulate the data based on the configuration parameters. For downlink transmission, the UE could determine a demodulation operation used to demodulate the data based on the configuration parameters.
[0215] At S902, performs uplink transmission.
[0216] The UE modulates data based on a selected modulation operation and transmits the data.
[0217] In an embodiment, for uplink transmission, the UE modulates the uplink data based on the first modulation operation and transmits the uplink data. Correspondingly, the TRP receives the uplink data and demodulates the uplink data based on first demodulation operation.
[0218] At S903, perform downlink transmission.
[0219] The UE receives data and demodulate the data based on a selected demodulation operation.
[0220] In an embodiment, for downlink transmission, the TRP modulates the downlink data based on the first modulation operation and transmits the downlink data. Correspondingly, the UE receives the downlink data and demodulates the downlink data based on the first demodulation operation.
[0221] The method according to the embodiments of this application is described in detail above with reference to FIGS. 4-9, and the related apparatus according to the embodiments of the present application will be described in detail below with reference to FIGS. 10-12.
[0222] FIG. 10 is a schematic block diagram of an apparatus 10 according to an embodiment of the present application. As shown in FIG. 10, the apparatus 10 includes:
[0223] a processing module 11, configured to modulate data based on a non-coherent modulation operation. A modulation symbol used in the non-coherent modulation operation is a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol has a same norm.
[0224] In possible implementations, the apparatus 10 may further include: a transmitter module 12 configured to transmit the second information. In possible implementations, the apparatus 10 may further include: a receiver module 13 configured to receive the first information.
[0225] In possible implementations, the processing module 11 may be implemented by a processor. The transmitter module 12 or receiver module 13 in this embodiment of this application may be implemented by a transceiver.
[0226] FIG. 11 is a schematic block diagram of another apparatus 20 according to an embodiment of this application. As shown in FIG. 11, the apparatus 20 includes:
[0227] a processing module 21, configured to demodulate data based on based on a non-coherent demodulation operation. A demodulation symbol used in the non-coherent demodulation operation is a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol has a same norm.
[0228] In possible implementations, the apparatus 20 may further include: a receiver module 22 configured to receive the second information. In possible implementations, the apparatus 20 may further include: a transmitter module 23, configured to transmit the first information.
[0229] In possible implementations, the processing module 21 may be implemented by a processor. The receiver module 22 or the transmitter module 23 in this embodiment of this application may be implemented by a transceiver.
[0230] As shown in FIG. 12, an apparatus 30 may include a transceiver 31. Optionally, the apparatus 30 may further include a processor 32 and / or a memory 33. The memory 33 may be configured to store indication information, or may be configured to store code, instructions, and the like that is to be executed by the processor 32.
[0231] The processor 32 may be an integrated circuit chip and have a signal processing capability. In an embodiment process, steps in the foregoing method embodiments can be implemented by using a hardware-integrated logical circuit in the processor, or by using instructions in the form of software. The processing module 11 may be a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) , or another programmable logic device, a discrete gate or a transistor logic device, or a discrete hardware component. All methods, steps, and logical block diagrams disclosed in these embodiments of the present application may be implemented or performed. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor or the like. Steps of the methods disclosed in the embodiments of the present invention may be directly performed and completed by a hardware decoding processor, or may be performed and completed by using a combination of hardware and software modules in the decoding processor. The software module may be located in a storage medium known in the art, such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, an electrically erasable programmable memory, or a register. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps in the foregoing methods in combination with the hardware of the processor.
[0232] It may be understood that the memory 33 in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include a volatile memory and a non-volatile memory. The non-volatile memory may be a ROM, a programmable read-only memory (PROM) , an erasable programmable read-only memory (EPROM) , an electrically erasable programmable read-only memory (EEPROM) , or a flash memory. The volatile memory may be a RAM, and be used as an external cache. Through example but not limitative description, many forms of RAMs may be used, for example, a static random access memory (SRAM) , a dynamic random access memory (DRAM) , a synchronous dynamic random access memory (SDRAM) , a double data rate synchronous dynamic random access memory (DDR SDRAM) , an enhanced synchronous dynamic random access memory (ESDRAM) , a synchronous link dynamic random access memory (SLDRAM) , and a direct rambus dynamic random access memory (DR RAM) . The storage of the system and the method described in this specification aim to include, but are not limited to, these and any other proper storage.
[0233] An embodiment of this application further provides a system. The system includes: the transmitting apparatus and the receiving apparatus in the foregoing embodiments.
[0234] An embodiment of this application further provides a computer storage medium, and the computer storage medium may store a program instruction for executing any of the foregoing methods.
[0235] Optionally, the storage medium may be specifically the memory 33.
[0236] A person of ordinary skill in the art will be aware that, in combination with the examples described in the embodiments disclosed in this specification, units and algorithm steps may be implemented by using electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by using hardware or software depends on particular applications and design constraint conditions of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the embodiment goes beyond the scope of this application.
[0237] It would be understood by a person skilled in the art that, for the purpose of convenience and brevity, in a detailed working process of the foregoing system, apparatus, and unit, reference may be made to a corresponding process in the foregoing method embodiments, and details are not described herein again.
[0238] In the several embodiments provided in this application, the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiment is merely an example. For example, the unit division is a logical function division and other methods of division may be used in an actual embodiment. For example, a plurality of units or components may be combined or integrated into another system, or some features may be ignored or not performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented using various communication interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or other forms.
[0239] The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, the parts may be located in one unit, or may be distributed among a plurality of network units. Some or all of the units may be selected based on actual requirements to achieve the objectives of the embodiments.
[0240] In addition, function units in the embodiments of this application may be integrated into one processing unit, each of the units may exist alone physically, or two or more units may be integrated into one unit.
[0241] When the functions are implemented in the form of a software functional unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. The technical solutions of this application may be implemented in the form of a software product. The software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a ROM, a RAM, a magnetic disk, an optical disc or the like.
[0242] The foregoing descriptions are merely specific embodiments of this application, but are not intended to limit the protection scope of this application. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.
Claims
1.A method for demodulation, comprising:demodulating data based on a non-coherent demodulation operation, a modulation symbol used in the non-coherent demodulation operation being a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol having a same norm.2.The method of claim 1, further comprising:transmitting first information, wherein the first information is used to determine a modulation operation used to modulate the data.3.The method of claim 1, further comprising:receiving second information, wherein the second information is used to determine a demodulation operation used to demodulate the data.4.The method of claim 2 or 3, whereinthe first information comprises a first parameter, wherein the first information indicates modulating the data based on a non-coherent modulation operation associated with the non-coherent demodulation operation when the first parameter is a first value; orthe second information comprises a first parameter, wherein the second information indicates demodulating the data based on the non-coherent demodulation operation when the first parameter is a first value.5.The method of claim 2 or 3, wherein the first information or the second information indicates one or more of: a first threshold, a second threshold, and a third threshold; whereinthe first threshold is a threshold for the number of samples able to be processed by a first user device, wherein the first user device is used to modulate or demodulate the data; the second threshold is a threshold of quantization related to an analog-to-digital converter (ADC) used at a receiver, and the third threshold is used to determine a type of the ADC used at the receiver, the type of the ADC comprises a first type of ADC or a second type of ADC, and resolution of the first type of ADC is lower than resolution of the second type of ADC.6.The method of claim 5, wherein the first information or the second information comprises a second parameter, whereinthe second parameter indicates the ADC used at the receiver to be the first type of ADC when the second parameter is a second value; or the second parameter indicates the ADC used at the receiver to be the second type of ADC when the second parameter is a third value.7.The method of claim 5, wherein the first information or the second information comprises a first indication to indicate a power consumption of the ADC used at the receiver, whereinthe ADC used at the receiver is the first type of ADC when the power consumption of the ADC used at the receiver is less than or equal to the third threshold; orthe ADC used at the receiver is the second type of ADC when the power consumption of the ADC used at the receiver is larger than the third threshold.8.The method of any one of claims 5 to 7, whereinthe non-coherent demodulation operation is determined to be used to demodulate the data, when the number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold; orthe non-coherent demodulation operation is determined to be used to demodulate the data, when the number of carriers is one, block error rate (BLER) performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.9.The method of any one of claims 1 to 8, further comprising:transmitting third information; orreceiving fourth information,wherein the third information or the fourth information indicates a relationship between a first element and a first vector, the first element is an element of the first dimension of the complex T-dimensional symbol, and the first vector is a vector comprising each element of the last (T-1) dimension (s) of the complex T-dimensional symbol.10.A method for modulation, comprising:modulating data based on a non-coherent modulation operation, a modulation symbol used in the non-coherent modulation operation being a complex T-dimensional symbol and each dimension of the complex T-dimensional symbol has a same norm.11.The method of claim 10, further comprising:receiving first information, wherein the first information is used to determine a modulation operation used to modulate the data.12.The method of claim 10 or 11, further comprising:transmitting second information, wherein the second information is used to determine a demodulation operation used to demodulate the data.13.The method of claim 11 or 12, whereinthe first information comprises a first parameter, wherein the first information indicates modulating the data based on the non-coherent modulation operation when the first parameter is a first value; orthe second information comprises a first parameter, wherein the second information indicates demodulating the data based on a non-coherent demodulation operation associated with the non-coherent modulation operation when the first parameter is a first value.14.The method of claim 11 or 12, wherein the first information or the second information indicates one or more of: a first threshold, a second threshold, and a third threshold; whereinthe first threshold is a threshold for the number of samples able to be processed by a first user device, wherein the first user device is used to modulate or demodulate the data; the second threshold is a threshold of quantization related to an analog-to-digital converter (ADC) used at a receiver, and the third threshold is used to determine a type of the ADC used at the receiver, the type of the ADC comprises a first type of ADC or a second type of ADC, and resolution of the first type of ADC is lower than resolution of the second type of ADC.15.The method of claim 14, wherein the first information or the second information comprises a second parameter, whereinthe second parameter indicates the ADC used at the receiver to be the first type of ADC when the second parameter is a second value; or the second parameter indicates the ADC used at the receiver to be the second type of ADC when the second parameter is a third value.16.The method of claim 14, wherein the first information or the second information comprises a first indication to indicate a power consumption of the ADC used at the receiver, whereinthe first information indicates the ADC used at the receiver to be the first type of ADC, when the power consumption of the ADC used at the receiver is less than or equal to the third threshold; orthe first information indicates the ADC used at the receiver to be the second type of ADC, when the power consumption of the ADC used at the receiver is larger than the third threshold.17.The method of any one of claims 14 to 16, whereinthe non-coherent modulation operation is determined to be used to modulate the data, when a number of carriers is one, the ADC used at the receiver is the first type of ADC and the minimum number of samples able to be processed by the first user device is less than or equal to the first threshold; orthe non-coherent modulation operation is determined to be used to modulate the data, when the number of carriers is one, BLER performance is not constraint, and the ADC used at the receiver is the second type of ADC and / or the minimum number of samples able to be processed by the first user device is larger than the first threshold.18.The method of any one of claims 10 to 17, further comprising:receiving third information; ortransmitting fourth informationwherein the third information or the fourth information indicates a relationship between a first element and a first vector, the first element is an element of the first dimension of the complex T-dimensional symbol, and the first vector is a vector comprising each element of the last (T-1) dimension (s) of the complex T-dimensional symbol.19.An apparatus, comprising a function or unit to perform the method of any one of claims 1 to 18.20.An apparatus, comprising a processor configured to cause the apparatus to perform the method of any one of claims 1 to 18.21.A computer readable storage medium comprising instructions, wherein when the instructions are executed by a computer, cause the computer to perform the method of any one of claims 1 to 18.22.A computer program comprising instructions which, when the program is executed by a computer, cause the computer to perform the method of any one of claims 1 to 18.23.A system, comprising a transmitting apparatus and a receiving apparatus, wherein the receiving apparatus performs the method of any one of claims 1 to 9, and the transmitting apparatus performs the method of any one of claims 10 to 18.
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