Method for selecting mcs of laco-ofdm modulation signal, terminal and network device

Abstract

A method, terminal, and network device for selecting the MCS of a LACO-OFDM modulated signal are disclosed. The method includes: the terminal demodulating a downlink reference signal sent by the network device to obtain channel quality indication information of the downlink reference signal at each layer, wherein the downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers; the terminal sending the channel quality indication information of the downlink reference signal at each layer to the network device for the network device to update the MCS of the LACO-OFDM modulated signal at each layer. This invention allows the network device to determine and update the MCS of the LACO-OFDM modulated signal at each layer based on information reported by the terminal, enabling adjustment of the MCS at each layer during LACO-OFDM modulation. This allows for flexible adjustment of the user experience and is particularly suitable for applications in mobile terminal scenarios and channel change scenarios, facilitating flexible resource allocation.

Description

Technical Field

[0001] This invention relates to the field of wireless optical communication technology, specifically to a method for selecting the MCS of a LACO-OFDM modulated signal, a terminal, and a network device. Background Technology

[0002] Optical Wireless Communications (OWC) is a novel wireless optical communication technology that utilizes light-emitting diodes (LEDs) or laser diodes (LDs) for communication, including visible light communications (VLC) and infrared communications. The transmitter in the system is typically composed of LEDs / LDs, which have high sensitivity and can transmit information by flashing signals at speeds imperceptible to the human eye. Furthermore, to accommodate illumination functions, white LEDs or red-green-blue LEDs can be used as transmitters in OWC. The photodetector (PD) at the receiver receives the corresponding optical signal and provides feedback in the form of current. Since the light produced by LED light sources is incoherent and does not contain phase information compared to electromagnetic waves, intensity modulation / direct detection (IM / DD) is commonly used in OWC.

[0003] Commonly used single-carrier modulation schemes in OWC include On-Off Keying (OOK), Pulse Width Modulation (PWM), and Pulse Position Modulation (PPM). Single-carrier modulation schemes are simple to implement but susceptible to inter-symbol interference. Currently, OFDM-based multi-carrier modulation is a hot research topic in OWC, but applying OFDM to OWC requires overcoming several problems: first, adjusting the OFDM input symbols to change the output symbols from complex to real values; second, converting the bipolar output symbols to unipolar symbols.

[0004] When the frequency domain symbol of the input Inverse Fast Fourier Transform (IFFT) module is Hermitian symmetric, the time domain symbol of the IFFT output will be real. Based on the method of unipolar symbol conversion, OWC-OFDM can be divided into Direct Current-based Optical OFDM (DCO-OFDM) and Asymmetrically-Clipped Optical OFDM (ACO-OFDM). DCO-OFDM adds a DC bias to all subcarriers to ensure signal unipolarity, which is easy to implement; however, the introduction of DC bias leads to reduced energy efficiency and cannot fully guarantee unipolarity. ACO-OFDM uses only odd-numbered subcarriers to transmit information and clips signals less than 0, then uses the characteristics of IFFT to achieve complete unipolarity. However, because only half of the subcarriers are used, its spectral efficiency will be half that of DCO-OFDM.

[0005] To flexibly balance energy efficiency and spectral efficiency, existing technologies have proposed layered ACO-OFDM (LACO-OFDM). LACO-OFDM modulation utilizes the center-antisymmetric characteristics of ACO-OFDM time-domain symbols and the down-clipping characteristics of odd and even subcarriers to distribute input symbols across multiple layers. Each layer undergoes ACO-OFDM once, and the final LACO-OFDM modulated signal is a superposition of the ACO-OFDM signals from each layer.

[0006] Figure 1 This illustrates the correspondence between layers and subcarrier sets in LACO-OFDM. If 16 subcarriers are currently used to transmit information, the input symbols need to be allocated to three different layers. The first layer uses the odd-numbered subcarriers (1, 3, ..., 15, numbered from 0 by default) to transmit information; this set of subcarriers is called the first layer. The second layer uses the remaining unused subcarriers from the first layer, but only uses the odd-numbered subcarriers (2, 6, 10, 14) for transmission; these subcarriers constitute the second layer. The third layer uses the subcarriers not used in both the first and second layers, again using only the odd-numbered subcarriers (4, 12); these subcarriers constitute the third layer. It can be seen that the layers in LACO-OFDM differ from those in MIMO; the layer relationships in LACO-OFDM are as described above.

[0007] It can be observed that when the number of layers is sufficiently high, LACO-OFDM can achieve the same spectral efficiency as DCO-OFDM. Furthermore, if each subcarrier uses the same electrical power, then with a sufficiently large number of layers, LACO-OFDM has a higher energy efficiency than DCO-OFDM.

[0008] Assume OFDM uses N subcarriers for transmission (where N is a power of 2, i.e., N = 2). n If the number of subcarriers and layers is n-1, then the maximum number of layers in the LACO-OFDM modulated signal is {1,...n-1}. Based on the number of subcarriers and layers, there are at least two power allocation methods for LACO-OFDM: 1) Equal subcarrier power allocation: The electrical power between adjacent layers differs by a factor of two, i.e., the electrical power of the (i+1)th layer is half the electrical power of the ith layer. Let the electrical power of the first layer of the LACO-OFDM modulated signal be P1, then the relationship between the number of layers and the power can be obtained as shown in Table 1 below; 2) Equal layer power allocation: The power of each layer is equal.

[0009] Table 1. 16-Point LACO-OFDM Power and Layer Number Correspondence Table

[0010] i-th layer Power of the i-th layer Total power 1 <![CDATA[P1]]> <![CDATA[P total ]]> 2 <![CDATA[P2=P1 / 2]]> <![CDATA[P total =P1+P1 / 2]]> 3 <![CDATA[P3=P1 / 4]]> <![CDATA[P total =P1+P1 / 2+P1 / 4]]>

[0011] Different power allocation schemes result in different electrical power usage in LACO-OFDM systems. When the system electrical power is related to the number of layers, LACO-OFDM is a modulation method that can flexibly configure indoor illumination and bit error rate (BER). Currently, there are no existing schemes for resource allocation under LACO-OFDM modulation. Therefore, a solution is urgently needed to achieve flexible resource allocation in LACO-OFDM modulation. Summary of the Invention

[0012] At least one embodiment of the present invention provides a method for selecting the MCS of a LACO-OFDM modulated signal, a terminal and a network device, which can realize flexible resource configuration of LACO-OFDM modulation.

[0013] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0014] In a first aspect, embodiments of the present invention provide a method for selecting the MCS of a LACO-OFDM modulated signal, comprising:

[0015] The terminal demodulates the downlink reference signal sent by the network device to obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers.

[0016] The terminal sends the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

[0017] Optionally, the terminal demodulates the downlink reference signal sent by the network device to obtain channel quality indication information of the downlink reference signal at each layer, including:

[0018] According to the preset number of layers, the downlink reference signal of each layer is demodulated to obtain the channel quality indication information of the downlink reference signal of each layer.

[0019] Optionally, the terminal demodulates the downlink reference signal sent by the network device to obtain channel quality indication information of the downlink reference signal at each layer, including:

[0020] Demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer;

[0021] Based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer, the channel quality indication information of the downlink reference signal of the remaining layers is calculated.

[0022] Optionally, the calculation of the channel quality indication information of the downlink reference signal of the remaining layer includes:

[0023] When the power allocation method is equal subcarrier power allocation, the signal-to-noise ratio (SNR) of the target layer is determined according to the channel quality indication information of the target layer; the SNR of the remaining layers is determined according to the SNR of the target layer and the difference between the SNRs of adjacent layers; and the channel quality indication information of the remaining layers is determined according to the SNR of the remaining layers.

[0024] When the power allocation method is equal-layer power allocation, the channel quality indication information of the downlink reference signal of the target layer is directly used as the channel quality indication information of the downlink reference signal of each remaining layer.

[0025] Optional, also includes:

[0026] The terminal receives configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0027] Optionally, the configuration information is carried in the downlink reference signal.

[0028] Secondly, embodiments of the present invention provide a method for selecting the MCS of a LACO-OFDM modulated signal, including:

[0029] The network device sends a downlink reference signal to the terminal, wherein the downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers;

[0030] The network device receives the channel quality indication information of the downlink reference signal at each layer sent by the terminal;

[0031] The network device updates the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer.

[0032] Optionally, updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes:

[0033] When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the channel quality ranking of each layer is determined according to the channel quality indication information of the downlink reference signal in each layer.

[0034] Based on the ranking of channel quality at each layer, the MCS of the LACO-OFDM modulated signal at each layer is updated. Wherein, when the channel quality at layer i is better than that at layer j, the modulation order of the MCS at layer i is not lower than that at layer j. The layer i or layer j can be any layer among the preset number of layers.

[0035] Optionally, updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes:

[0036] When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the range of values ​​for the modulation order of the MCS is determined according to the channel quality indication information of the downlink reference signal in each layer.

[0037] Within the range of the modulation order of the MCS, the MCS of the LACO-OFDM modulation signal in each layer is updated, wherein when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

[0038] Optionally, updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes:

[0039] When the power allocation method of the downlink reference signal among the layers is equal layer power allocation, an MCS is determined based on the channel quality indication information of the downlink reference signal in any layer, which serves as the MCS of the LACO-OFDM modulated signal in each layer.

[0040] Optional, also includes:

[0041] The network device sends configuration information to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0042] Thirdly, embodiments of the present invention provide a terminal, including a transceiver and a processor, wherein...

[0043] The processor is used to demodulate the downlink reference signal sent by the network device and obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers.

[0044] The transceiver is used to send the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

[0045] Optionally, the processor is further configured to demodulate the downlink reference signal of each layer according to the preset number of layers to obtain channel quality indication information of the downlink reference signal of each layer.

[0046] Optionally, the processor is further configured to demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer; and calculate the channel quality indication information of the downlink reference signal of the remaining layers based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer.

[0047] Optionally, the processor is further configured to:

[0048] When the power allocation method is equal subcarrier power allocation, the signal-to-noise ratio (SNR) of the target layer is determined according to the channel quality indication information of the target layer; the SNR of the remaining layers is determined according to the SNR of the target layer and the difference between the SNRs of adjacent layers; and the channel quality indication information of the remaining layers is determined according to the SNR of the remaining layers.

[0049] When the power allocation method is equal-layer power allocation, the channel quality indication information of the downlink reference signal of the target layer is directly used as the channel quality indication information of the downlink reference signal of each remaining layer.

[0050] Optionally, the transceiver is further configured to receive configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0051] Optionally, the configuration information is carried in the downlink reference signal.

[0052] Fourthly, embodiments of the present invention provide a terminal, including: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method described in the first aspect.

[0053] Fifthly, embodiments of the present invention provide a network device, including a transceiver and a processor, wherein,

[0054] The transceiver is used to send a downlink reference signal to the terminal, the downlink reference signal being a LACO-OFDM modulated signal with a preset number of layers; and to receive channel quality indication information of the downlink reference signal sent by the terminal at each layer.

[0055] The processor is configured to update the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer.

[0056] Optionally, the processor is further configured to:

[0057] When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the channel quality ranking of each layer is determined according to the channel quality indication information of the downlink reference signal in each layer.

[0058] Based on the ranking of channel quality at each layer, the MCS of the LACO-OFDM modulated signal at each layer is updated. Wherein, when the channel quality at layer i is better than that at layer j, the modulation order of the MCS at layer i is not lower than that at layer j. The layer i or layer j can be any layer among the preset number of layers.

[0059] Optionally, the processor is further configured to:

[0060] When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the range of values ​​for the modulation order of the MCS is determined according to the channel quality indication information of the downlink reference signal in each layer.

[0061] Within the range of the modulation order of the MCS, the MCS of the LACO-OFDM modulation signal in each layer is updated, wherein when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

[0062] Optionally, the processor is further configured to:

[0063] When the power allocation method of the downlink reference signal among the layers is equal layer power allocation, an MCS is determined based on the channel quality indication information of the downlink reference signal in any layer, which serves as the MCS of the LACO-OFDM modulated signal in each layer.

[0064] Optionally, the transceiver is further configured to send configuration information to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0065] In a sixth aspect, embodiments of the present invention provide a network device, including: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method described in the second aspect.

[0066] In a seventh aspect, embodiments of the present invention provide a computer-readable storage medium storing a program that, when executed by a processor, implements the steps of the method described above.

[0067] Compared with the prior art, the method for selecting the MCS of the LACO-OFDM modulated signal, the terminal, and the network device provided in this embodiment of the invention allow the network device to determine and update the MCS of the LACO-OFDM modulated signal at each layer based on the information reported by the terminal. This enables the adjustment of the MCS at each layer during LACO-OFDM modulation, thereby allowing for flexible adjustment of the user experience. It is particularly suitable for applications in mobile terminal scenarios and channel change scenarios, and is beneficial for flexible resource allocation. Attached Figure Description

[0068] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0069] Figure 1 This is a schematic diagram showing the correspondence between the middle layer and the subcarrier set in LACO-OFDM.

[0070] Figure 2 This is a flowchart illustrating the MCS selection method for LACO-OFDM modulated signals in this embodiment of the invention when applied to the terminal side.

[0071] Figure 3 This is a flowchart illustrating the MCS selection method for LACO-OFDM modulated signals according to an embodiment of the present invention when applied to the network device side;

[0072] Figure 4 This is an example of an interactive flow diagram of the layer number control method according to an embodiment of the present invention;

[0073] Figure 5 This is a schematic diagram of the noise and received SNR of each layer when using equal subcarrier power allocation in an embodiment of the present invention;

[0074] Figure 6 This is a schematic diagram of the structure of a terminal according to an embodiment of the present invention;

[0075] Figure 7 This is a schematic diagram of the structure of a terminal according to another embodiment of the present invention;

[0076] Figure 8 This is a schematic diagram of the structure of a network device according to an embodiment of the present invention;

[0077] Figure 9 This is a schematic diagram of the structure of a network device according to another embodiment of the present invention;

[0078] Figure 10 This is a schematic diagram of the structure of a terminal according to another embodiment of the present invention;

[0079] Figure 11 This is a schematic diagram of the structure of a network device according to another embodiment of the present invention. Detailed Implementation

[0080] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0081] The terms “first,” “second,” etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus. The terms “and / or” in the specification and claims indicate at least one of the connected objects.

[0082] The following description provides examples and is not intended to limit the scope, applicability, or configuration set forth in the claims. Changes may be made to the function and arrangement of the elements discussed without departing from the spirit and scope of this disclosure. Various procedures or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with reference to certain examples may be combined in other examples.

[0083] In this embodiment of the invention, the base station can adjust the user experience in real time by configuring different MCS (Modulation and Coding Schemes) for each layer of the LACO-OFDM modulated signal for the same user. For example, a low bit rate MCS can be used when the performance of a certain layer is poor, and a high bit rate MCS can be used when the performance is good. In addition, all layers can use the same MCS or different MCS, thereby achieving a flexibility that existing O-OFDM technology does not possess.

[0084] For example, existing technologies using DCO-OFDM and ACO-OFDM cannot allow a user to use multiple MCSs simultaneously, and existing technologies have not proposed a method for selecting MCSs for each layer of LACO-OFDM. The embodiments of this invention can flexibly adjust the user experience by adjusting the MCSs used in each layer of LACO-OFDM, and can be applied in terminal mobile scenarios and channel change scenarios, which is beneficial for flexible resource allocation. It should also be noted that the number of layers mentioned in this document refers to the number of layers used in LACO-OFDM modulation.

[0085] Please refer to Figure 2 The method for selecting the MCS of the LACO-OFDM modulated signal according to embodiments of the present invention, when applied to the terminal side, includes:

[0086] Step 21: The terminal demodulates the downlink reference signal sent by the network device to obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers.

[0087] Here, the network device can specifically be an access point (AP). The network device transmits a downlink reference signal. The downlink reference is a LACO-OFDM modulated signal, and its layer number is a preset number.

[0088] Step 22: The terminal sends the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

[0089] Here, the terminal sends the obtained downlink reference signal channel quality indication information at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer according to the channel quality indication information, thereby enabling flexible resource configuration of LACO-OFDM modulation.

[0090] As one implementation, in step 21 above, the terminal can demodulate the downlink reference signal of each layer according to the preset number of layers, thereby obtaining the channel quality indication information of the downlink reference signal of each layer.

[0091] As another implementation, in step 21 above, the terminal can demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer; then, based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer, the channel quality indication information of the downlink reference signal of the remaining layers is calculated.

[0092] Here, the target layer is any one of the preset number of layers. The remaining layers are the layers other than the target layer among the preset number of layers. For example, if the preset number of layers is 4, that is, the LACO-OFDM modulated signal has 4 layers, then the target layer can be the 1st layer of the 4 layers. The terminal demodulates the downlink reference signal of the 1st layer to obtain the channel quality indication information of the downlink reference signal of the 1st layer. Then, according to the power allocation method of the downlink reference signal among the layers, the channel quality indication information of the downlink reference signals of the 2nd, 3rd, and 4th layers adjacent to the 1st layer is calculated sequentially. Of course, the target layer can also be the 2nd, 3rd, or 4th layer of the 4 layers.

[0093] For example, when the power allocation method is equal subcarrier power allocation, this embodiment of the invention can determine the signal-to-noise ratio (SNR) of the target layer based on the channel quality indication information of the target layer; and determine the SNR of the remaining layers based on the SNR of the target layer and the difference between the SNRs of adjacent layers. Here, the difference between the SNRs of adjacent layers is typically around 3 dB (for example, the power difference between adjacent layers in Table 1 is a factor of two). Then, the channel quality indication information of the remaining layers is determined based on the SNR of the remaining layers. When determining the SNR corresponding to a certain channel quality indication information, or when determining the channel quality indication information corresponding to a certain SNR, it can be determined based on the mapping relationship between signal-to-noise ratio (SNR) and channel quality index (CQI).

[0094] For example, when the power allocation method is equal-layer power allocation, it can be assumed that the channel quality indication information of each layer is roughly the same. In this case, the channel quality indication information of the downlink reference signal of the target layer can be directly used as the channel quality indication information of the downlink reference signal of each remaining layer.

[0095] In step 22 above, when the power allocation method is equal subcarrier power allocation, the terminal can send the channel quality indication information of the downlink reference signal at each layer to the network device, or send the channel quality indication information of the downlink reference signal at the first layer to the network device, so as to reduce the amount of data that needs to be transmitted. When the power allocation method is equal layer power allocation, the terminal sends the channel quality indication information of the downlink reference signal at any layer to the network device.

[0096] In addition, to assist the terminal in receiving / demodulating the downlink reference signal, in this embodiment of the invention, the network device can also send configuration information to the terminal. The terminal receives the configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power allocation method of the downlink reference signal among the layers. Thus, the terminal can determine the number of layers, power allocation method, and other information of the downlink reference signal sent by the network device based on the configuration information. Optionally, the configuration information can be carried in the downlink reference signal.

[0097] Please refer to Figure 3 The method for selecting the MCS of the LACO-OFDM modulated signal according to embodiments of the present invention, when applied to network devices (such as APs), includes:

[0098] Step 31: Send a downlink reference signal to the terminal. The downlink reference signal is a LACO-OFDM modulation signal with a preset number of layers.

[0099] Step 32: The network device receives the channel quality indication information of the downlink reference signal at each layer sent by the terminal;

[0100] Step 33: The network device updates the MCS of the LACO-OFDM modulated signal at each layer according to the channel quality indication information of the downlink reference signal at each layer.

[0101] Through the above steps, the embodiments of the present invention can enable network devices to determine and update the MCS of the LACO-OFDM modulation signal at each layer based on the information reported by the terminal. This enables the adjustment of the MCS at each layer during LACO-OFDM modulation, thereby allowing for flexible adjustment of the user experience. It is particularly suitable for applications in mobile terminal scenarios and channel change scenarios, and is beneficial for flexible resource allocation.

[0102] As one implementation, in step 33 above, the network device can determine the channel quality ranking of each layer based on the channel quality indication information of the downlink reference signal in each layer, provided that the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation. Then, based on the channel quality ranking of each layer, the MCS of the LACO-OFDM modulated signal in each layer is updated. Wherein, when the channel quality of the i-th layer is better than that of the j-th layer, the modulation order of the MCS of the i-th layer is not lower than that of the MCS of the j-th layer, where the i-th layer or the j-th layer is any layer from the preset number of layers. In other words, layers with better channel quality can use MCS with a higher modulation order; layers with poorer channel quality can use MCS with a lower modulation order. This allows for the selection of an appropriate MCS modulation order based on the channel quality of each layer, balancing communication quality and spectral efficiency, and achieving a trade-off between the two.

[0103] As another implementation, in step 33 above, the network device can determine the range of modulation order of the MCS based on the channel quality indication information of the downlink reference signal at each layer, provided that the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation. For example, based on a preset correspondence between channel quality and MCS modulation order, the MCS modulation order corresponding to the channel quality indication information with the worst channel quality is determined as the upper limit (highest modulation order) of the range. The lower limit of the range can be set to 2, thus obtaining the range. Then, within the range of the modulation order of the MCS, the MCS of the LACO-OFDM modulated signal at each layer is updated, wherein when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, where the i-th layer or the j-th layer is any layer among the preset layers. Thus, within this range, in each layer of the LACO-OFDM modulated signal, lower layers use lower modulation orders, and higher layers can use higher modulation orders.

[0104] As another implementation, in step 33 above, the network device can determine an MCS (including modulation order) based on the channel quality indication information of the downlink reference signal at any layer when the power allocation method is equal-layer power allocation. This MCS is then used as the MCS of the LACO-OFDM modulated signal at each layer. Since the channel quality indication information is the same at each layer, the current channel quality corresponding to the channel quality indication information at any layer can be determined. Then, based on the preset correspondence between channel quality and MCS modulation order, the modulation order corresponding to the current channel quality is determined as the updated modulation order.

[0105] After updating the MCS of the LACO-OFDM modulated signal at each layer, the network device can send signals (including sending downlink reference signals) to the terminal according to the updated MCS.

[0106] In addition, in this embodiment of the invention, the network device can also send configuration information to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power allocation method of the downlink reference signal among the layers. By sending the above configuration information, the terminal can better receive / demodulate the downlink reference signal.

[0107] Figure 4 Taking the transmitting device as the access point (AP) and the receiving device as the UE as an example, an interaction flow between devices according to the above-described method of this invention is given, which mainly includes:

[0108] A. Configure the AP with a power allocation method and send the DRS according to this power allocation method.

[0109] A1) AP power allocation methods include:

[0110] (1) First power allocation method: equal subcarrier power allocation (i.e., the power of each layer is twice that of the next layer).

[0111] (2) Second power distribution method: equal layer power distribution (i.e., the power of each layer is the same).

[0112] A2) The AP sends the DRS (LACO-OFDM modulated signal) to the UE using the initially configured power allocation method. The DRS may include the following information:

[0113] (1) The power distribution method currently in use.

[0114] B. The UE demodulates the DRS, calculates the CQI, and reports the results.

[0115] B1) The UE demodulates the received DRS to obtain the current power allocation method.

[0116] B2) When using the first power allocation method, the UE calculates the CQI for each layer. The specific calculation method is as follows:

[0117] (1) Calculation method 1: Decode the first layer DRS, calculate the first layer CQI, and then calculate the next layer CQI.

[0118] i. The received SNR of each layer is 3dB lower than that of the previous layer. The received SNR of each layer is then calculated based on this SNR relationship, and the CQI of each layer is obtained according to the SNR mapping. Figure 5 This is a schematic diagram of the received SNR and BER at each layer under 64QAM and the first power allocation method. Figure 5 The left half of the image shows the noise power of layers 1 to 5 when the subcarrier power is allocated, arranged from top to bottom along the vertical axis. The right half shows the received SNR of layers 1 to 5 when the subcarrier power is allocated, arranged from top to bottom along the vertical axis.

[0119] (2) Calculation method 2: Decode each layer of DRS separately and calculate each layer of CQI.

[0120] B3) When the second power allocation method is used, calculate the CQI of the first layer, and then calculate the CQI of the next layer.

[0121] (1) Calculation method 1: Decode the first layer DRS, calculate the first layer CQI, and then the CQI of each layer is consistent with the first layer.

[0122] i. Calculate the SNR of the first layer and obtain the CQI of the first layer based on the SNR mapping. The CQI of each subsequent layer is consistent with this. At this point, the received SNR and BER of each layer are approximately equal.

[0123] B4) The UE reports the CQI values ​​of each layer to the AP.

[0124] (1) In the first power allocation mode, report the CQI of each layer or the first layer CQI.

[0125] (2) In the second power allocation mode, the first layer CQI is reported.

[0126] C. AP selects MCS based on the reported results.

[0127] C1) When using the first power allocation method, each layer uses a different MCS or the same MCS based on the reported CQI. Specifically, this includes, but is not limited to, the following MCS selection methods:

[0128] (1) MCS selection method 1: The lower layer uses a high-order modulation MCS, and the higher layer uses a low-order modulation MCS. The maximum modulation order used can be determined based on the MCS modulation order corresponding to the channel quality indication information with the worst channel quality.

[0129] i. Lower layer: The smaller layer in the index {1,...l}, where l represents the total number of layers, and the smaller layer can be from 1 to m, where m is less than l.

[0130] ii. Higher level: The higher level in the index {1,...l}, where the higher level can be m+1 to l.

[0131] (2) MCS selection method 2: Layers with better CQI use high-order modulated MCS, and layers with poorer CQI use low-order modulated MCS.

[0132] C2) When the second power allocation method is used, the MCS of the first layer is determined based on the reported CQI, and the same MCS is used for each subsequent layer.

[0133] The various methods of the embodiments of the present invention have been described above. Apparatus for implementing the above methods will now be provided.

[0134] Please refer to Figure 6 This invention also provides a terminal 600, comprising:

[0135] The first demodulation module 601 is used to demodulate the downlink reference signal sent by the network device and obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers.

[0136] The first transmitting module 602 is used to transmit the channel quality indication information of the downlink reference signal at each layer to the network device, so as to enable the network device to update the MCS of the LACO-OFDM modulated signal at each layer.

[0137] Optionally, the first demodulation module is further configured to demodulate the downlink reference signal of each layer according to the preset number of layers, and obtain the channel quality indication information of the downlink reference signal of each layer.

[0138] Optionally, the first demodulation module is further configured to demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer; and calculate the channel quality indication information of the downlink reference signal of the remaining layers based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer.

[0139] Optionally, the first demodulation module is further configured to, when the power allocation method is equal subcarrier power allocation, determine the signal-to-noise ratio (SNR) of the target layer based on the channel quality indication information of the target layer; determine the SNR of the remaining layers based on the SNR of the target layer and the difference between the SNRs of adjacent layers; and determine the channel quality indication information of the remaining layers based on the SNR of the remaining layers; and, when the power allocation method is equal layer power allocation, directly use the channel quality indication information of the downlink reference signal of the target layer as the channel quality indication information of the downlink reference signal of each remaining layer.

[0140] Optionally, the terminal further includes:

[0141] The first receiving module is used to receive configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0142] Optionally, the configuration information is carried in the downlink reference signal.

[0143] Please refer to Figure 7 The present invention also provides a terminal 700, including: a transceiver 701 and a processor 702;

[0144] The processor 702 is used to demodulate the downlink reference signal sent by the network device and obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers.

[0145] The transceiver 701 is used to send the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

[0146] Optionally, the processor is further configured to demodulate the downlink reference signal of each layer according to the preset number of layers to obtain channel quality indication information of the downlink reference signal of each layer.

[0147] Optionally, the processor is further configured to demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer; and calculate the channel quality indication information of the downlink reference signal of the remaining layers based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer.

[0148] Optionally, the processor is further configured to, when the power allocation method is equal subcarrier power allocation, determine the signal-to-noise ratio (SNR) of the target layer based on the channel quality indication information of the target layer; determine the SNR of the remaining layers based on the SNR of the target layer and the difference between the SNRs of adjacent layers; and determine the channel quality indication information of the remaining layers based on the SNR of the remaining layers; and, when the power allocation method is equal layer power allocation, directly use the channel quality indication information of the downlink reference signal of the target layer as the channel quality indication information of the downlink reference signal of each remaining layer.

[0149] Optionally, the transceiver is further configured to receive configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0150] Optionally, the configuration information is carried in the downlink reference signal.

[0151] It should be noted that the device in this embodiment corresponds to the method applied to the terminal side described above. The implementation methods in each of the above embodiments are applicable to the embodiments of this device and can achieve the same technical effect. The device provided by the embodiments of the present invention can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail.

[0152] Please refer to Figure 8 This invention also provides a network device 800, comprising:

[0153] The first transmitting module 801 is used to transmit a downlink reference signal to the terminal, wherein the downlink reference signal is a LACO-OFDM modulation signal with a preset number of layers;

[0154] The first receiving module 802 is used to receive the channel quality indication information of the downlink reference signal at each layer sent by the terminal;

[0155] The first update module 803 is used to update the MCS of the LACO-OFDM modulated signal in each layer according to the channel quality indication information of the downlink reference signal in each layer.

[0156] Optionally, the first updating module is further configured to, when the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, determine the order of channel quality of each layer according to the channel quality indication information of the downlink reference signal in each layer; and update the MCS of the LACO-OFDM modulated signal in each layer according to the order of channel quality of each layer, wherein when the channel quality of the i-th layer is better than that of the j-th layer, the modulation order of the MCS of the i-th layer is not lower than that of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer in the preset number of layers.

[0157] Optionally, the first updating module is further configured to, when the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, determine the range of values ​​for the modulation order of the MCS based on the channel quality indication information of the downlink reference signal in each layer; and update the MCS of the LACO-OFDM modulated signal in each layer within the range of values ​​for the modulation order of the MCS, wherein, when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

[0158] Optionally, the first update module is further configured to determine an MCS as the MCS of the LACO-OFDM modulated signal in each layer, based on the channel quality indication information of the downlink reference signal in any layer when the power allocation method is equal-layer power allocation.

[0159] Optionally, the network device further includes:

[0160] The second transmitting module is used to transmit configuration information to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0161] It should be noted that the device in this embodiment corresponds to the method applied to the network side described above. The implementation methods in each of the above embodiments are applicable to the embodiments of this device and can achieve the same technical effect. The device provided by the embodiments of the present invention can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail.

[0162] Please refer to Figure 9 The present invention also provides a network device 900, including: a transceiver 901 and a processor 902;

[0163] The transceiver 901 is used to send a downlink reference signal to the terminal, the downlink reference signal being a LACO-OFDM modulation signal with a preset number of layers; and to receive channel quality indication information of the downlink reference signal sent by the terminal at each layer.

[0164] The processor 902 is used to update the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer.

[0165] Optionally, the processor is further configured to, when the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, determine the channel quality ranking of each layer according to the channel quality indication information of the downlink reference signal in each layer; and update the MCS of the LACO-OFDM modulated signal in each layer according to the channel quality ranking of each layer, wherein when the channel quality of the i-th layer is better than that of the j-th layer, the modulation order of the MCS of the i-th layer is not lower than that of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

[0166] Optionally, the processor is further configured to, when the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, determine the range of values ​​for the modulation order of the MCS based on the channel quality indication information of the downlink reference signal in each layer; and update the MCS of the LACO-OFDM modulated signal in each layer within the range of values ​​for the modulation order of the MCS, wherein, when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

[0167] Optionally, the processor is further configured to, when the power allocation method is equal-layer power allocation, determine an MCS based on the channel quality indication information of the downlink reference signal in any layer, as the MCS of the LACO-OFDM modulated signal in each layer.

[0168] Optionally, the transceiver is further configured to send configuration information from the network device to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

[0169] It should be noted that the device in this embodiment corresponds to the method applied to the network side described above. The implementation methods in each of the above embodiments are applicable to the embodiments of this device and can achieve the same technical effect. The device provided by the embodiments of the present invention can implement all the method steps implemented in the above method embodiments and can achieve the same technical effect. Here, the parts that are the same as those in the method embodiments and the beneficial effects will not be described in detail.

[0170] Please refer to Figure 10 The present invention also provides a terminal 1000, including a processor 1001, a memory 1002, and a computer program stored in the memory 1002 and executable on the processor 1001. When the computer program is executed by the processor 1001, it implements the various processes of the above-described random access method embodiment executed by the terminal and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0171] Please refer to Figure 11 The present invention also provides a network device 1100, including a processor 1101, a memory 1102, and a computer program stored in the memory 1102 and executable on the processor 1101. When the computer program is executed by the processor 1101, it implements the various processes of the above-described random access method embodiment executed by the network device and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0172] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the various processes of the above-described random access method embodiments and achieves the same technical effects. To avoid repetition, it will not be described again here. The computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0173] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0174] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0175] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for selecting the MCS of a LACO-OFDM modulated signal, characterized in that, include: The terminal demodulates the downlink reference signal sent by the network device to obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers. The terminal sends the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

2. The method as described in claim 1, characterized in that, The terminal demodulates the downlink reference signal sent by the network device to obtain channel quality indication information of the downlink reference signal at each layer, including: According to the preset number of layers, the downlink reference signal of each layer is demodulated to obtain the channel quality indication information of the downlink reference signal of each layer.

3. The method as described in claim 1, characterized in that, The terminal demodulates the downlink reference signal sent by the network device to obtain channel quality indication information of the downlink reference signal at each layer, including: Demodulate the downlink reference signal of the target layer to obtain the channel quality indication information of the downlink reference signal of the target layer; Based on the power allocation method of the downlink reference signal among the layers and the channel quality indication information of the downlink reference signal of the target layer, the channel quality indication information of the downlink reference signal of the remaining layers is calculated.

4. The method as described in claim 3, characterized in that, The calculated channel quality indication information for the downlink reference signal of the remaining layer includes: When the power allocation method is equal subcarrier power allocation, the signal-to-noise ratio (SNR) of the target layer is determined according to the channel quality indication information of the target layer; the SNR of the remaining layers is determined according to the SNR of the target layer and the difference between the SNRs of adjacent layers; and the channel quality indication information of the remaining layers is determined according to the SNR of the remaining layers. When the power allocation method is equal-layer power allocation, the channel quality indication information of the downlink reference signal of the target layer is directly used as the channel quality indication information of the downlink reference signal of each remaining layer.

5. The method as described in claim 1, characterized in that, Also includes: The terminal receives configuration information sent by the network device, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

6. The method as described in claim 5, characterized in that, The configuration information is carried in the downlink reference signal.

7. A method for selecting the MCS of a LACO-OFDM modulated signal, characterized in that, include: The network device sends a downlink reference signal to the terminal, wherein the downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers; The network device receives the channel quality indication information of the downlink reference signal at each layer sent by the terminal; The network device updates the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer.

8. The method as described in claim 7, characterized in that, The step of updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes: When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the channel quality ranking of each layer is determined according to the channel quality indication information of the downlink reference signal in each layer. Based on the ranking of channel quality at each layer, the MCS of the LACO-OFDM modulated signal at each layer is updated. Wherein, when the channel quality at layer i is better than that at layer j, the modulation order of the MCS at layer i is not lower than that at layer j. The layer i or layer j can be any layer among the preset number of layers.

9. The method as described in claim 7, characterized in that, The step of updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes: When the power allocation method of the downlink reference signal among the layers is equal subcarrier power allocation, the range of values ​​for the modulation order of the MCS is determined according to the channel quality indication information of the downlink reference signal in each layer. Within the range of the modulation order of the MCS, the MCS of the LACO-OFDM modulation signal in each layer is updated, wherein when i is greater than j, the modulation order of the MCS of the i-th layer is not lower than the modulation order of the MCS of the j-th layer, and the i-th layer or the j-th layer is any layer among the preset number of layers.

10. The method as described in claim 7, characterized in that, The step of updating the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer includes: When the power allocation method of the downlink reference signal among the layers is equal layer power allocation, an MCS is determined based on the channel quality indication information of the downlink reference signal in any layer, which serves as the MCS of the LACO-OFDM modulated signal in each layer.

11. The method as described in claim 7, characterized in that, Also includes: The network device sends configuration information to the terminal, wherein the configuration information includes at least one of the following: the number of subcarriers of the LACO-OFDM modulated signal, the number of layers of the LACO-OFDM modulated signal, and the power distribution method of the downlink reference signal among the layers.

12. A terminal, characterized in that, Includes transceivers and processors, among which, The processor is used to demodulate the downlink reference signal sent by the network device and obtain the channel quality indication information of the downlink reference signal at each layer. The downlink reference signal is a LACO-OFDM modulated signal with a preset number of layers. The transceiver is used to send the channel quality indication information of the downlink reference signal at each layer to the network device, so that the network device can update the MCS of the LACO-OFDM modulated signal at each layer.

13. A terminal, characterized in that, include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method as described in any one of claims 1 to 6.

14. A network device, characterized in that, Includes transceivers and processors, among which, The transceiver is used to send a downlink reference signal to the terminal, the downlink reference signal being a LACO-OFDM modulated signal with a preset number of layers; and to receive channel quality indication information of the downlink reference signal sent by the terminal at each layer. The processor is configured to update the MCS of the LACO-OFDM modulated signal at each layer based on the channel quality indication information of the downlink reference signal at each layer.

15. A network device, characterized in that, include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the steps of the method as described in any one of claims 7 to 11.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the method as described in any one of claims 1 to 11.

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