Non-orthogonal multiple access method for power line communication under multi-service coexistence

Abstract

The present application relates to the technical field of power line communication, and in particular to a power line communication non-orthogonal multiple access method under multi-service coexistence, wherein first, a relay adopts a beamforming technology based on maximum ratio combination to receive signals of indoor users, and the maximum direction of the beam is aligned with a URLLC user; second, the relay broadcasts a threshold value of an accessible channel, schedules one eMBB user satisfying the threshold value in each time slot, shares spectrum resources with the URLLC user by using a non-orthogonal multiple access technology, and further adjusts its own transmission power by using an adaptive power control algorithm based on threshold value judgment; and finally, the relay transmits the superimposed multiple user signals in the frequency domain to a destination node after decoding. The present application multiplexes eMBB services and URLLC services in the same time-frequency resource, guarantees the low-latency and high-reliability characteristics of the URLLC service, ensures the quality of service requirements of the eMBB user with lower power consumption, and thus completes the communication process under the condition of multi-service coexistence.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power line communication, and particularly relates to a power line communication non-orthogonal multiple access method under multi-service coexistence. BACKGROUND

[0002] With the rapid development of the 5th generation mobile networks (5G), the new power system of the mutual integration of power network and communication network also accelerates the construction process, so that the power system puts forward the demand of super high speed, large-scale access, low data transmission delay and high reliability to the communication technology. The 5G wireless communication technology supports three different service types: enhanced mobile broadband (eMBB), massive machine type communications (mMTC) and ultra-reliable low latency communications (URLLC). Among them, the eMBB service is applied to intelligent inspection, video monitoring and other scenes with high transmission rate in the power system, and the URLLC user is applied to power emergency command, remote scheduling and other scenes sensitive to delay and with super high requirement for reliability.

[0003] In the scenario of coexistence of eMBB and URLLC services, eMBB service occupies more frequency resources, and URLLC service has higher transmission priority, so the two services will compete for resources in the system. Since the transmission data volume of URLLC service is small, allocating dedicated frequency resources for it will cause waste of resources, therefore, it is necessary to study the reuse of eMBB service and URLLC service in the same time-frequency resource, and guarantee the quality of service demand of eMBB user while guaranteeing the low delay and high reliability characteristics of URLLC service.

[0004] In view of the above problems, the present application provides a power line communication non-orthogonal multiple access method under multi-service coexistence, which guarantees the low delay and high reliability characteristics of URLLC service, and at the same time, guarantees the quality of service demand of eMBB user with lower power consumption, so as to complete the communication process under the condition of multi-service coexistence. SUMMARY

[0005] The application provides a power line communication non-orthogonal multiple access method under multi-service coexistence, which combines power line communication and relay technology, solves the problems of long-distance communication and the like in traditional power line communication, and enables indoor multiple eMBB users and URLLC users to access a relay through a radio frequency wireless link, so that different services share spectrum resources through non-orthogonal multiple access technology to improve spectrum efficiency; the relay equipped with multiple antennas adopts a maximum ratio combining beamforming technology to enhance the gain of URLLC users and improve the reliability of the URLLC users; the eMBB users adopt adaptive power control based on threshold judgment to ensure the low-latency and high-reliability characteristics of URLLC services and the quality of service requirements of the eMBB users at a low power cost; the relay adopts a decode-and-forward protocol to transmit user signals to a destination node through a power line communication link, so that the communication process under multi-service coexistence is completed, and the communication requirements under the multi-service coexistence condition in the field of smart grids and the like are met.

[0006] The technical scheme adopted by the application is as follows:

[0007] The application provides a power line communication non-orthogonal multiple access method under multi-service coexistence, which combines power line communication and relay technology, solves the problems of long-distance communication and the like in traditional power line communication, and enables indoor multiple eMBB users and URLLC users to access a relay through a radio frequency wireless link, so that different services share spectrum resources through non-orthogonal multiple access technology to improve spectrum efficiency; the relay equipped with multiple antennas adopts a maximum ratio combining beamforming technology to enhance the gain of URLLC users and improve the reliability of the URLLC users; the eMBB users adopt adaptive power control based on threshold judgment to ensure the low-latency and high-reliability characteristics of URLLC services and the quality of service requirements of the eMBB users at a low power cost; the relay adopts a decode-and-forward protocol to transmit user signals to a destination node through a power line communication link, so that the communication process under multi-service coexistence is completed, and the communication requirements under the multi-service coexistence condition in the field of smart grids and the like are met.

[0008] Step 1: the relay receives signals of indoor users through a maximum ratio combining beamforming technology, the indoor users include multiple eMBB users and URLLC users, and the maximum direction of the beam is aligned with the URLLC users;

[0009] Step 2: the relay broadcasts a threshold of an accessible channel, schedules an eMBB user satisfying the threshold condition in each time slot, and accesses the relay through non-orthogonal multiple access technology;

[0010] Step 3: the eMBB user adjusts the transmission power through an adaptive power control algorithm based on threshold judgment according to the quality of service requirement of the eMBB user;

[0011] Step 4: the relay transmits multiple user signals after frequency domain superposition to a destination node.

[0012] Further, in the step 1,

[0013] The relay receives the signal of the indoor user by using the beamforming technology based on the maximum ratio combination, the maximum direction of the beam is aligned to the URLLC user, and the beamforming weight vector is wherein, represents the channel vector of the URLLC user, represents the conjugate transpose operation on the channel vector of the URLLC user.

[0014] Further, in the step 2,

[0015] The threshold of the accessible channel broadcasted by the relay is represented as

[0016] The eMBB user satisfying the threshold condition is screened out , wherein, represents the conjugate transpose operation on the beamforming weight vector, represents the channel vector of the eMBB user, i represents the total number of eMBB users. M An eMBB user satisfying the threshold condition is scheduled in each time slot, and the non-orthogonal multiple access technology is used to access the relay, and the data rates of the URLLC user and the eMBB user are respectively represented as:

[0017]

[0018]

[0019]

[0020] wherein, represents the data rate of the URLLC user, represents the transmission power of the URLLC user, represents the power of the additive white Gaussian noise, represents the data rate of the eMBB user, i represents the transmission power of the eMBB user. i Further, in the step 3,

[0021] The service quality requirement of the eMBB user itself is represented as:

[0022]

[0023]

[0024] wherein, represents the target data rate of the eMBB user. i ​​​​​

[0025] Further, in the step 3,

[0026] The eMBB user adjusts its transmission power according to its service quality requirement through the adaptive power control algorithm based on threshold judgment:

[0027]

[0028] Wherein, , Pmax represents the maximum transmission power of the eMBB user; i

[0029] If the maximum transmission power is still unable to meet the service quality requirement, the eMBB user is no longer accessed in the time slot.

[0030] Further, in the step 4,

[0031] The relay adopts the decode-forward protocol, transmits the superimposed multiple user signals in the frequency domain to the destination node through the power line communication link, and thus completes the communication process of the multi-service coexistence.

[0032] Compared with the prior art, the power line communication non-orthogonal multiple access method under multi-service coexistence has the beneficial effects that: the power line communication and the relay technology are organically combined to solve the problems of the traditional power line communication, such as the inability to realize long-distance communication; and the indoor multiple eMBB users and URLLC users access the relay through the radio frequency wireless link, and the different services share the spectrum resources through the non-orthogonal multiple access technology to improve the spectrum efficiency; on the premise of ensuring the reliable access of the URLLC user, the eMBB user adjusts the transmission power through the adaptive power control algorithm based on threshold judgment, so as to meet the service quality requirement at a lower power cost. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0034] Figure 1 The flow chart of the power line communication non-orthogonal multiple access method under multi-service coexistence of the present application. DETAILED DESCRIPTION

[0035] The embodiments of the present application will be described in detail below with reference to the drawings.

[0036] ​The embodiment of the application provides a power line communication non-orthogonal multiple access method under multi-service coexistence, which organically combines power line communication and relay technology, and effectively solves the problems that traditional power line communication cannot realize long-distance communication and the like. The non-orthogonal multiple access technology is adopted to enable eMBB services and URLLC services to share time-frequency resources. Through the maximum ratio combining beamforming technology, the gain of the URLLC user is improved, and through the adaptive power control algorithm based on threshold judgment, the quality of service requirement of the eMBB user is ensured at a low power cost while the low delay and high reliability characteristics of the URLLC service are ensured. The embodiment considers a power line communication system under multi-service coexistence, and there are a plurality of eMBB users and URLLC users in the indoor environment.

[0037] The embodiment of the application provides a power line communication non-orthogonal multiple access method under multi-service coexistence, which organically combines power line communication and relay technology, and effectively solves the problems that traditional power line communication cannot realize long-distance communication and the like. The non-orthogonal multiple access technology is adopted to enable eMBB services and URLLC services to share time-frequency resources. Through the maximum ratio combining beamforming technology, the gain of the URLLC user is improved, and through the adaptive power control algorithm based on threshold judgment, the quality of service requirement of the eMBB user is ensured at a low power cost while the low delay and high reliability characteristics of the URLLC service are ensured. The embodiment considers a power line communication system under multi-service coexistence, and there are a plurality of eMBB users and URLLC users in the indoor environment.

[0038] Step 1: The relay receives the signals of the indoor users by adopting the maximum ratio combining beamforming technology, the indoor users include a plurality of eMBB users and URLLC users, and the maximum direction of the beam is aligned with the URLLC users; according to the high reliability requirement of the URLLC users, the URLLC user with the optimal channel condition is selected to access;

[0039] Step 2: The relay broadcasts the threshold of the accessible channel, schedules an eMBB user meeting the threshold condition in each time slot, and accesses the relay by adopting the non-orthogonal multiple access technology; and the reliable access of the eMBB user and the URLLC user is ensured under the condition of sharing wireless resources;

[0040] Step 3: The eMBB user adjusts the transmission power thereof according to the quality of service requirement of the eMBB user by adopting the adaptive power control algorithm based on threshold judgment;

[0041] Step 4: The relay transmits the superimposed signals of the decoded plurality of users in the frequency domain to a destination node.

[0042] Specifically, in step 1,

[0043] The relay receives the signals of the indoor users by adopting the maximum ratio combining beamforming technology, and the beamforming weight vector is , wherein, HURLLC represents the channel vector of the URLLC user, HURLLC represents the conjugate transpose operation on the channel vector of the URLLC user, the maximum direction of the beam is aligned with the URLLC user, and thus the gain and transmission reliability of the URLLC user are improved.

[0044] Specifically, in step 2,

[0045] The threshold of the accessible channel broadcasted by the relay to the eMBB user is represented as ;

[0046] The eMBB users satisfying the threshold condition are screened out , wherein, represents the conjugate transpose operation on the beamforming weight vector, represents the channel vector of the i th eMBB user, M represents the total number of eMBB users.

[0047] An eMBB user satisfying the threshold condition is scheduled in each time slot, and a non-orthogonal multiple access technology is used to access the relay, so as to ensure that the eMBB user and the URLLC user can access reliably in the case of sharing wireless resources.

[0048] The superimposed signal received by the relay is represented as:

[0049]

[0050] , wherein represents the transmission power of the i th eMBB user, represents the signal of the i th eMBB user, represents the transmission power of the URLLC user, represents the signal of the URLLC user, represents the additive white Gaussian noise with a mean of 0 and a variance of .

[0051] The data rates of the URLLC user and the eMBB user are represented as:

[0052]

[0053]

[0054] , wherein, represents the data rate of the URLLC user, represents the power of the additive white Gaussian noise, represents the data rate of the i th eMBB user.

[0055] Specifically, in step 3,

[0056] The quality of service requirement of the eMBB user itself is represented as:

[0057]

[0058] , wherein, represents the target data rate of the i th eMBB user.

[0059] Furthermore, in step 3,

[0060] eMBB users adjust their transmit power based on their service quality requirements using an adaptive power control algorithm that is based on threshold judgment:

[0061]

[0062] in, , Indicates the first i Maximum transmit power of each eMBB user;

[0063] The adaptive power control algorithm can save transmission power while ensuring the quality of service requirements of eMBB users. If the quality of service requirements cannot be met even when transmitting at the maximum transmission power, no more eMBB users will be connected in that time slot.

[0064] Specifically, in step 4,

[0065] The relay uses a decoding and forwarding protocol to transmit the decoded user signals to the destination node after superimposing them in the frequency domain through the power line communication link, thereby completing the communication process of multiple services coexisting.

[0066] In summary, this embodiment provides a non-orthogonal multiple access (NOMA) method for power line communication under multi-service coexistence. Multiple terminals with different service types connect to a relay via wireless access. The relay employs a decoding-forwarding protocol to transmit terminal signals to the destination node through the power line communication link. First, the relay uses maximum ratio beamforming (MRB) to receive signals from indoor users, with the maximum beam direction aligned with the URLLC user. Second, the relay broadcasts the threshold for accessible channels, scheduling one eMBB user that meets the threshold conditions in each time slot. It shares spectrum resources with the URLLC user using non-orthogonal multiple access technology and further adjusts its own transmit power through an adaptive power control algorithm based on threshold judgment. Finally, the relay uses a decoding-forwarding protocol to transmit user signals to the destination node through the power line communication link. Compared with existing methods, this embodiment multiplexes eMBB services and URLLC services on the same time-frequency resources, and through threshold-based adaptive power control for eMBB users, it ensures the low latency and high reliability of URLLC services while guaranteeing the quality of service requirements of eMBB users with lower power overhead, thereby completing the communication process under the condition of multi-service coexistence.

[0067] Any procedural or methodological descriptions in the flow charts or otherwise described herein can be understood to represent circuitry, fragments or portions of code comprising executable instructions for carrying out one or more steps of a particular logic function or procedure, and the scope of the preferred embodiments of the present application includes additional implementations in which the functions can be performed in an order other than that shown or discussed, including in a substantially simultaneous manner or in reverse order, as will be appreciated by those skilled in the art to which embodiments of the present application pertain.

[0068] Those skilled in the art can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by programs instructing relevant hardware, and the programs can be stored in a computer readable storage medium. When the programs are executed, one or a combination of the steps of the method embodiments is included.

[0069] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0070] The above embodiments only describe the preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by ordinary engineering technicians in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A non-orthogonal multiple access method for power line communication under multi-service coexistence, characterized in that, The method includes the following steps: Step 1: The relay uses beamforming technology based on maximum ratio combining to receive signals from indoor users, including multiple eMBB users and URLLC users. The maximum beam direction is aligned with the URLLC users. Step 2: The threshold for the relay broadcast access channel is set, and an eMBB user that meets the threshold condition is scheduled in each time slot to access the relay using non-orthogonal multiple access technology; Step 3: eMBB users adjust their transmit power based on their own quality of service requirements using an adaptive power control algorithm that is based on threshold judgment. Step 4: The relay transmits the decoded user signals, after superimposing them in the frequency domain, to the destination node; In step 1: The repeater uses beamforming technology based on maximum ratio combining to receive signals from indoor users. The beam's maximum direction is aligned with the URLLC user, and the beamforming weight vector is... ,in, Represents the channel vector of a URLLC user. This indicates a conjugate transpose operation on the channel vector of a URLLC user; In step 2: The threshold for the accessible channels of the relay broadcast is expressed as follows: ; Filter out those that meet the threshold conditions eMBB users, among whom This indicates a conjugate transpose operation on the beamforming weight vector. Indicates the first i Channel vectors for each eMBB user M This indicates the total number of eMBB users; In each time slot, one eMBB user meeting the threshold condition is scheduled to access the relay using non-orthogonal multiple access technology. The data rates for URLLC users and eMBB users are expressed as follows: in, Indicates the data rate for URLLC users. Indicates the transmit power of URLLC users. This represents the power of additive white Gaussian noise. Indicates the first i Data rate per eMBB user Indicates the first i Transmit power of each eMBB user; In step 3: The service quality requirements of the eMBB user are expressed as follows: in, Indicates the first i Target data rate for each eMBB user; In step 3: eMBB users adjust their transmit power based on their service quality requirements using an adaptive power control algorithm that is based on threshold judgment: in, , Indicates the first i Maximum transmit power of each eMBB user; If the service quality requirements cannot be met even when transmitting at maximum power, no more eMBB users will be connected in that time slot.

2. The non-orthogonal multiple access method for power line communication under multi-service coexistence as described in claim 1, characterized in that, In step 4 The relay uses a decoding and forwarding protocol to transmit the decoded user signals to the destination node after superimposing them in the frequency domain through the power line communication link, thereby completing the communication process of multiple services coexisting.

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