A D2D resource allocation method based on terminal mobility in 5G system

Abstract

The present invention discloses a D2D resource allocation method based on terminal mobility under a 5G system, including: allocating power to mobile terminals according to the moving speed of cellular users, and calculating the receiving level deviation of cellular users; screening cellular users that meet the qualified conditions as a qualified set based on D2D user pairs, and calculating the receiving level deviation of D2D user pairs; screening corresponding cellular users as channel reuse objects of D2D user pairs according to preset judgment conditions. The present invention can better integrate D2D technology in the 5G system, and minimize the interference between D2D user pairs and cellular users, and fully consider the spectrum reuse performance of the cell to select and allocate appropriate channel resources to D2D user pairs; while achieving the optimal guarantee of the perception of cellular users and D2D user pairs while weakening interference, thereby maximizing the spectrum resource utilization and system performance of the 5G system.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and in particular to a D2D resource allocation method based on terminal mobility in a 5G system. Background Art

[0002] The introduction of D2D (Device-to-Device) communication in 5G cellular networks can greatly improve both system performance and user experience. As a result, D2D technology has received widespread attention and application. However, while D2D communication has brought great improvements to the quality of cellular networks, it has also brought complex interference. Therefore, how to control the interference in D2D communication networks, including the interference of D2D users to cellular users and the interference between D2D users, is crucial. Therefore, wireless resource management, especially resource allocation algorithms and reasonable user power allocation, are the top priorities. Existing scholars often focus on weakening the impact of interference through CoMP multi-point cooperative transmission technology and differentiated power control, but CoMP will increase the load on the 5G system.

[0003] The "Clustered D2D Resource Allocation Method Based on Energy Constraints and Interference Limitation Areas" disclosed in Chinese patent documents has a publication number of CN108810855B and a publication date of 2020-10-02. The method includes: obtaining information about the energy obtained by the D2D user equipment from the surrounding environment before the end of the odd time slot of the current resource scheduling frame; allocating resource blocks to each of the cellular user equipment, and calculating the transmission power of the D2D user equipment based on the energy obtained by the D2D user equipment from the surrounding environment; removing D2D user equipment whose transmission power is less than a preset minimum transmission power threshold from the D2D user equipment; allocating resource blocks to each of the cellular user equipment, and clustering the D2D user equipment with the cellular user equipment as the cluster head based on the interference limitation area of ​​the cellular user equipment and the interference limitation area of ​​the D2D user equipment; allocating corresponding transmission power to the cellular user equipment and the D2D user equipment in each cluster. However, the above research directions and CoMP technology will increase the load of the 5G system. Summary of the invention

[0004] The present invention aims to overcome the problem in the prior art that in order to reduce interference between D2D users and cellular users, the load of the 5G system will be additionally increased during resource allocation for D2D users, and provides a D2D resource allocation method based on terminal mobility in a 5G system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A D2D resource allocation method based on terminal mobility in a 5G system, comprising:

[0007] Power is allocated to mobile terminals according to the moving speed of cellular users, and the receiving level deviation of cellular users is calculated; cellular users that meet the qualified conditions are screened as a qualified set based on D2D user pairs, and the receiving level deviation of D2D user pairs is calculated;

[0008] The corresponding cellular users are selected according to the preset judgment conditions as the channel multiplexing objects of the D2D user pairs.

[0009] A D2D resource allocation method TMB-PC (5G Terminal Mobility based Device-to-Device Resource Allocation algorithm with power control), firstly, the allocated power of the system to single resource block and multiple resource blocks of cellular users at different moving speeds is calculated respectively, and then the final allocated power is converted with the aid of elasticity coefficient; according to the distance between the cellular user and the base station, the corresponding received signal level deviation value is calculated; according to the distance between the D2D user pair and the cellular user and the base station, the received signal level and deviation of each D2D user pair are calculated, and the cellular user set with a long distance from the D2D user pair and small interference is screened out, and the cellular user with the minimum received signal level deviation or the maximum signal-to-noise ratio is further identified as the target channel reuse object; finally, preferably according to the number of resource blocks occupied by the cellular user, the resource block with the largest interference isolation is selected from them and provided to the D2D user pair for reuse; it can better integrate D2D technology in the 5G system, minimize the interference between the D2D user pair and the cellular user, and fully consider the spectrum reuse performance of the cell to select the appropriate channel resources to be allocated to the D2D user pair.

[0010] Preferably, the process of allocating power to the mobile terminal includes:

[0011] Setting the full transmission power of the cellular cell and calculating the normal transmission power of the cellular cell based on the redundancy factor;

[0012] Allocate initial multi-resource block power to the cellular user according to the moving speed of the cellular user;

[0013] According to the signal-to-noise ratio of the cellular user, the final multi-resource block power and the final single resource block power are allocated to the cellular user.

[0014] Preferably, the calculating of the receiving level deviation of the cellular user comprises:

[0015] Calculate the path loss of the cellular link for cellular users;

[0016] The receiving level deviation of the cellular user is calculated according to the ideal receiving level value of the cellular user and the actual receiving signal level.

[0017] Preferably, the screening process of the qualified set includes:

[0018] Filter out the jth D2D user pair Dpr j Cellular users whose distance is greater than the distance threshold join Dpr j The qualified set of

[0019] If all cellular users go to Dpr j If the distance between them is less than the distance threshold, then Dpr j The most distant cellular user joins Dpr j Qualified set.

[0020] Preferably, the calculating the receiving level deviation of the D2D user comprises:

[0021] Calculate the path loss of the D2D link of the D2D user;

[0022] The receiving level deviation of the D2D user pair is calculated according to the ideal receiving level value of the D2D user pair and the receiving signal level of the cellular user resource blocks in the qualified set multiplexed by the D2D user pair.

[0023] As a preferred embodiment, based on the j-th D2D user pair Dpr j The receiving level deviation Pofd j , from D2D users to Dpr j The qualified set screens out cellular users whose receiving level deviation is greater than Pofd j cellular users, forming the D2D user pair Dpr j The reuse set.

[0024] Preferably, allocating initial multiple resource block powers to cellular users includes:

[0025] For the i-th cellular user Usr i , when its moving speed is greater than or equal to the speed threshold, the initial single resource block power is calculated based on the full power of the cellular cell transmission;

[0026] When its moving speed is less than the speed threshold, the initial single resource block power is calculated based on the normal transmit power of the cellular cell;

[0027] Initial multiple resource block powers are allocated based on the initial single resource block powers.

[0028] As a preference, for the i-th cellular user Usr i, when its signal-to-noise ratio is less than the signal-to-noise ratio threshold, the initial multi-resource block power of the cellular user is the final multi-resource block power;

[0029] When the signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold, the final multi-resource block power is corrected by a set elastic coefficient; and the final single resource block power is allocated based on the final multi-resource block power.

[0030] Preferably, the preset judgment conditions include:

[0031] If the reuse set of the D2D user pair is empty, the cellular user with the smallest receiving level deviation is selected from the qualified set as the channel reuse object of the D2D user pair;

[0032] If it is not empty, the cellular user with the largest signal-to-noise ratio is selected from the reuse set as the channel reuse object of the D2D user pair.

[0033] Preferably, when the number of resource blocks occupied by the cellular user selected as the channel multiplexing object is greater than one, the resource blocks are divided into a resource block occupied set that has been multiplexed by the D2D user and a resource block idle set that has not been multiplexed;

[0034] Corresponding resource blocks are allocated from the idle set of resource blocks to D2D user pairs for multiplexing.

[0035] The present invention has the following beneficial effects: it can calculate the allocated system initial power of the cellular user based on the redundancy factor according to the moving speed of the cellular user, and can optimize the power allocation differently according to the elasticity coefficient; it can calculate the received signal level deviation of the cellular user according to the cell location; it can calculate the path loss and received signal level deviation of the D2D user pair according to the cell location of the D2D user pair; it can screen out the resource blocks that produce the minimum signal deviation to the cellular user due to channel multiplexing under the interference of the D2D user, so as to provide quality assurance for improving the service usage perception of the D2D user pair; it can better integrate the D2D technology in the 5G system, minimize the interference between the D2D user pair and the cellular user, and fully consider the spectrum multiplexing performance of the cell to select the appropriate channel resources to be allocated to the D2D user pair. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a flow chart of a D2D resource allocation method based on terminal mobility of the present invention.

[0037] Figure 2 It is a flow chart of the power allocation and receiving level deviation calculation for cellular users in the present invention.

[0038] Figure 3 This is a flow chart of the qualified set screening and reception level deviation calculation for D2D user pairs in the present invention.

[0039] Figure 4 It is a flow chart of selecting cellular users as channel multiplexing objects of D2D user pairs in the present invention.

[0040] Figure 5 This is a comparison chart of system throughput between the resource allocation method of the present invention and other resource allocation methods.

[0041] Figure 6 This is a comparison chart of system satisfaction between the resource allocation method of the present invention and other resource allocation methods. DETAILED DESCRIPTION

[0042] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0043] like Figure 1 As shown, a D2D resource allocation method based on terminal mobility in a 5G system includes:

[0044] Power is allocated to mobile terminals according to the moving speed of cellular users, and the receiving level deviation of cellular users is calculated; cellular users that meet the qualified conditions are screened as a qualified set based on D2D user pairs, and the receiving level deviation of D2D user pairs is calculated;

[0045] The corresponding cellular users are selected according to the preset judgment conditions as the channel multiplexing objects of the D2D user pairs.

[0046] It should be noted that the present invention is a D2D resource allocation method TMB-PC (5G Terminal Mobility based Device-to-Device Resource Allocation algorithm with power control), firstly, the allocated power of the system to single resource block and multiple resource blocks of cellular users at different moving speeds is calculated respectively, and then the final allocated power is converted with the aid of elasticity coefficient; according to the distance between the cellular user and the base station, the corresponding received signal level deviation value is calculated; according to the distance between the D2D user pair and the cellular user and the base station, the received signal level and deviation of each D2D user pair are calculated, and the cellular user set with a long distance from the D2D user pair and small interference is screened out, and the cellular user with the minimum received signal level deviation or the maximum signal-to-noise ratio is further identified as the target channel reuse object; finally, preferably according to the number of resource blocks occupied by the cellular user, the resource block with the largest interference isolation is selected from them and provided to the D2D user pair for reuse; it can better integrate D2D technology in the 5G system, minimize the interference between the D2D user pair and the cellular user, and fully consider the spectrum reuse performance of the cell to select the appropriate channel resources to be allocated to the D2D user pair.

[0047] It is worth noting that the definitions of various parameters in the present invention include: single cell eNodeB, total number of physical resource blocks Nm RB There are m cellular users USR = {Usr1, Usr2, ..., Usr m}, and there are n D2D user pairs DPR = {Dpr1, Dpr2, ..., Dpr n}; The distance between each cellular user and the cell base station DSU = {Dsu1, Dsu2, ..., Dsu m}, the mobile rate of the cellular user VLC = {Vlc1, Vlc2, ..., Vlc m}, the number of resource blocks occupied by cellular users NRB = {Nrb1, Nrb2, ..., Nrb m}, cellular user service signal-to-noise ratio SNR = {Snr1, Snr2,…, Snr m}; The distance between each D2D user pair and the cell base station DSD = {Dsd1, Dsd2, ..., Dsd n}; Any D2D user j ,j∈[1,n] and any cellular user Usr i , the distance Ddu of i∈[1,m] j,i , DDU={Ddu j,i} is a j*i matrix.

[0048] As a specific example, Figure 2 As shown, the process of allocating power to the mobile terminal includes:

[0049] Setting the full transmission power of the cellular cell and calculating the normal transmission power of the cellular cell based on the redundancy factor;

[0050] Allocate initial multi-resource block power to the cellular user according to the moving speed of the cellular user;

[0051] According to the signal-to-noise ratio of the cellular user, the final multi-resource block power and the final single resource block power are allocated to the cellular user.

[0052] Specifically, the full power of the cell transmission is set to Pwr tx , in dBm; the corresponding speed threshold is Vlc th , in km / h; the redundancy factor is ε∈(0,0.5); the normal transmission power of the cellular cell is calculated by taking the logarithm of the difference between one and the redundancy factor, multiplying it by ten and adding it to the full transmission power of the cellular cell: Pwr en =Pwr tx+10*log(1-ε), in dBm, where log(·) is the common logarithm function.

[0053] Optionally, allocating initial multiple resource block powers to the cellular user includes:

[0054] For the i-th cellular user Usr i , when its moving speed is greater than or equal to the speed threshold, the initial single resource block power is calculated based on the full power of the cellular cell transmission;

[0055] When its moving speed is less than the speed threshold, the initial single resource block power is calculated based on the normal transmit power of the cellular cell;

[0056] Initial multiple resource block powers are allocated based on the initial single resource block powers.

[0057] Specifically, for any cellular user Usr i ,i∈[1,m], if the moving speed is greater than or equal to the speed threshold Vlc i ≥Vlc th , the initial single resource block power Pwr allocated by the system to the cellular user is calculated based on the full power of the cellular cell transmission i =Pwr tx -10*log(Nm RB )(dBm), the difference is the product of the full transmission power of the cellular cell and the total number of physical resource blocks multiplied by ten; if the condition is met and the mobile speed is less than the speed threshold Vlc i <Vlc th , the initial single resource block power Pwr allocated by the system to the cellular user is calculated based on the normal transmission power of the cellular cell i =Pwr en -10*log(Nm RB )(dBm), the product of the logarithm of the normal transmission power of the cellular cell and the total number of physical resource blocks multiplied by ten is used as the difference. Calculate Usr for any cellular user i Initial allocated multi-resource block power Puf i =Pwr i +10*log(Nrb i )(dBm), take the logarithm of the number of physical resource blocks occupied by cellular users, multiply it by ten and then add it to the initial single resource block power.

[0058] Optionally, for the i-th cellular user Usr i , when its signal-to-noise ratio is less than the signal-to-noise ratio threshold, the initial multi-resource block power of the cellular user is the final multi-resource block power;

[0059] When the signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold, the final multi-resource block power is corrected by a set elastic coefficient; and the final single resource block power is allocated based on the final multi-resource block power.

[0060] Specifically, set the elastic coefficient γ∈(0.5,1], the signal-to-noise ratio threshold SNR th (dB); for any cellular user Usr i ,i∈[1,m], if the condition is met, the signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold Snr i ≥SNR th , then the final multi-resource block power Pul allocated to the user is calculated according to the elasticity coefficient i =Puf i *γ; if the signal-to-noise ratio is less than the signal-to-noise ratio threshold Snr i <SNR th , then calculate the final multi-resource block power Pul allocated to the user i =Puf i ; Calculate the final single resource block power Pul allocated to the user i ′=Pul i -10*log(Nrb i )(dBm), the final multi-resource block power is multiplied by ten times the logarithm of the number of physical resource blocks occupied by the cellular user.

[0061] As a specific embodiment, calculating the receiving level deviation of a cellular user includes:

[0062] Calculate the path loss of the cellular link for cellular users;

[0063] The receiving level deviation of the cellular user is calculated according to the ideal receiving level value of the cellular user and the actual receiving signal level.

[0064] The specific steps include:

[0065] Set the path loss constant Lsc of the cellular link us , the path loss coefficient of the cellular link Lsi us ; For any cellular user Usr i ,i∈[1,m], calculate the path loss Lsus of its normal link i =Lsc us +Lsi us *log(Dsu i / 1000)(dB), the logarithm of the distance between the cellular user and the cell base station multiplied by the path loss coefficient of the cellular link plus the path loss constant of the cellular link.

[0066] Set the ideal receiving level value RSRP for cellular users iu(dBm); Calculate the i-th cellular user Usr i The received signal level RSPu i =Pul i -Lsus i (dBm), the final multi-resource block power minus the path loss; calculate the i-th cellular user Usr i The receiving level deviation Pofu i =abs(RSPu i -RSRP iu ) / RSRP iu , the absolute value of the difference between the received signal level of the cellular user and the ideal received level value, divided by the ideal received level value, where abs(·) is the absolute value function.

[0067] As a specific example, Figure 3 As shown, the screening process of the qualified set of the j-th D2D user pair includes: screening out the j-th D2D user pair Dpr j Cellular users whose distance is greater than or equal to the distance threshold join Dpr j If all cellular users to Dpr j If the distance between them is less than the distance threshold, then Dpr j The most distant cellular user joins Dpr j Qualified set.

[0068] Specifically, set the distance threshold DST th (m); for the jth D2D user Dpr j , j∈[1,n], filter out all users whose distance to the jth D2D user pair is greater than or equal to the distance threshold Ddu j,i ≥DST th The cellular users are included in the jth D2D user pair Dpr j Qualified set Stok j If all cellular users meet the condition Ddu j,i <DST th , then the jth D2D user pair Dpr j The farthest cellular user Usr i Included in its qualified set Stok j middle.

[0069] Further, calculating the receiving level deviation of the D2D user includes:

[0070] Calculate the path loss of the D2D link of the D2D user;

[0071] The receiving level deviation of the D2D user pair is calculated according to the ideal receiving level value of the D2D user pair and the receiving signal level of the cellular user resource blocks in the qualified set multiplexed by the D2D user pair.

[0072] Set the path loss constant Lsc of the D2D link dd , the path loss coefficient Lsi of the D2D link dd ; Calculate the jth D2D user Dpr j The path loss Lsdd j =Lsc dd +Lsi dd *log(Dsd j / 1000)(dB), the logarithm of the distance between the D2D user and the cell base station multiplied by the path loss coefficient of the D2D link plus the path loss constant of the D2D link.

[0073] Specifically, for the qualified set Stok of the j-th D2D user pair j All cellular users k∈[1,j t ], where j t Dpr j The number of qualified cellular users owned by the user pair is used to calculate the number of resource blocks occupied by the jth D2D user pair Dpr j Multiplexed receive signal level Cellular users The final single resource block power minus the j-th D2D user Dpr j of path loss.

[0074] Set the ideal receiving level value RSRP of D2D user pair id (dBm); Calculate the jth D2D user pair Dpr j The receiving level deviation Pofd j = abs(RSPd j -RSRP id ) / RSRP id ; The absolute value of the difference between the received signal level of the D2D user and the ideal received signal level, divided by the ideal received signal level.

[0075] As a specific example, Figure 4 As shown, based on the jth D2D user pair Dpr j The receiving level deviation Pofd j , from D2D users to Dpr j Qualified set Stok j Filter out the receiving level deviation of cellular users Greater than or equal to Pofd j of cellular users Composition of D2D user pairs Dpr j The reuse set Stmu j .

[0076] The preset judgment conditions include:

[0077] If the reuse set of the D2D user pair is empty, the cellular user with the smallest receiving level deviation is selected from the qualified set as the channel reuse object of the D2D user pair;

[0078] If it is not empty, the cellular user with the largest signal-to-noise ratio is selected from the reuse set as the channel reuse object of the D2D user pair.

[0079] Specifically, if the conditions are met: the reuse set Stmu j The number of elements Ns j ≥1, the cellular user with the largest signal-to-noise ratio is selected as the jth D2D user pair Dpr j Channel multiplexing object; if the multiplexing set Stmu j Empty, that is, Ns j = 0, then from the qualified set Stok j The cellular user with the smallest receiving level deviation is selected as the jth D2D user pair Dpr j Channel multiplexing object.

[0080] Further, when the number of resource blocks occupied by the cellular user selected as the channel multiplexing object is greater than one, the resource blocks are divided into a resource block occupied set that has been multiplexed by the D2D user and an idle set of resource blocks that have not been multiplexed;

[0081] Corresponding resource blocks are allocated from the idle set of resource blocks to D2D user pairs for multiplexing.

[0082] Specifically, if the jth D2D user has j If the channel reuse object occupies multiple resource blocks, the resource blocks that have been reused by other D2D users are selected to form an occupation set. The remaining unused resource blocks form the idle set If the possession set If it is not empty, select Select the distance occupancy set The resource block with the farthest resource block number in the resource block number is allocated to the jth D2D user pair Dpr j ;If possessing set If it is empty, then select Select a resource block with the largest number from the D2D user pair Dpr j If the channel reuse object occupies only one resource block, the resource block is allocated to the jth D2D user pair Dpr j.

[0083] The D2D resource allocation method based on terminal mobility of the present invention starts with analyzing the mobility performance of users in the cellular network, supplemented by differentiated transmission power, and then combined with different service signal-to-noise ratio performances to provide a flexible and adjustable power configuration; according to the ideal receiving level value of the cellular user, its receiving level deviation value is calculated; according to the distance between the D2D user pair and the cellular user, the cellular users with long distance and small interference are preliminarily screened out as candidate users for channel multiplexing; then the receiving level deviation value of each D2D user pair is calculated, and the cellular users with small D2D interference and minimum receiving level deviation are further screened out as the final multiplexed users, so as to achieve the optimal guarantee of the perception of the cellular user and the D2D user pair while weakening the interference, thereby maximizing the spectrum resource utilization and system performance of the 5G system.

[0084] This embodiment takes the number of cellular users m=5 and the number of D2D user pairs n=3 as an example to specifically illustrate the present invention. The distribution of cellular users in the 5G cell is shown in Table 1.

[0085] Table 1 Distribution of cellular users

[0086]

[0087]

[0088] The distribution of D2D user pairs in the 5G cell is shown in Table 2.

[0089] Table 2 Distribution of D2D user pairs

[0090]

[0091] The basic data are shown in Table 3.

[0092] Table 3 Basic data

[0093] project data Operating frequency (GHz) 2.6 Operating bandwidth (MHz) 100 Subcarrier bandwidth index μ 1 <![CDATA[Full - configured power of cell transmission, Pwr tx (dBm)]]> 43 <![CDATA[Speed threshold Vlc th (km / h)]]> 80 Redundancy factor ε 0.3 Elastic modulus γ 0.8 <![CDATA[Signal-to-noise ratio threshold SNR th (dB)]]> 0 <![CDATA[Path loss constant Lsc of the cellular link us > 128.1 <![CDATA[Path loss coefficient Lsi of the cellular link us > 37.6 <![CDATA[The ideal received signal power level RSRP for cellular users iu (dBm)]]> -80 <![CDATA[Distance threshold DST th (m)]]> 100 <![CDATA[Path loss constant Lsc of the D2D link dd > 148 <![CDATA[Path loss coefficient Lsi of the D2D link dd > 40 <![CDATA[Ideal received level value of RSRP for D2D user pair id (dBm)]]> -90

[0094] This example describes a D2D resource allocation method based on terminal mobility in a 5G system, including the following steps: mobile terminal power allocation, cellular user reception level deviation calculation, target qualified cellular user screening, D2D user reception level deviation calculation, and channel multiplexing object screening.

[0095] Step 1: Allocate power to mobile terminals based on the moving speed of cellular users.

[0096] Step 1-1: The cellular cell transmits at full power Pwr tx (dBm), speed threshold Vlc th(km / h), redundancy factor ε∈(0,0.5) and other parameters are detailed in basic data table 3; calculate the normal transmission power Pwr of the cellular cell en =Pwr tx +10*log(1-ε)=41.45(dBm).

[0097] Step 1-2: According to the subcarrier bandwidth index μ=1 in Table 3, the total number of physical resource blocks Nm of the cell can be obtained RB =273; meets the condition Vlc i ≥Vlc th = 80 cellular users are {Usr3, Usr5}, and the initial single resource block power Pwr allocated by the system to these two users is calculated. i =Pwr tx -10*log(Nm RB )=18.64(dBm); The remaining users {Usr1,Usr2,Usr4} meet the condition Vlc i <Vlc th , calculate the initial single resource block power Pwr allocated by the system to these three users i =Pwr en -10*log(Nm RB )=17.09(dBm); calculate any cellular user Usr i The initial multi-resource block power Puf i =Pwr i +10*log(Nrb i ) = {17.09, 21.86, 21.65, 23.11, 23.41} (dBm), the data in brackets are arranged in ascending order according to the cellular user subscript.

[0098] Step 1-3: Cellular users {Usr1, Usr2, Usr3, Usr5} satisfy the condition Snr i ≥SNR th =0, then calculate the final multi-resource block power Pul allocated to these four users i =Puf i *γ={13.67,17.49,17.32,18.73}(dBm); Usr4 satisfies the condition Snr i <SNR th =0, then calculate the final multi-resource block power Pul allocated by Usr4 i =Puf i =23.11 (dBm); Calculate the final single resource block power Pul′ allocated to all cellular users {Usr1, Usr2, Usr3, Usr4, Usr5} i =Puli -10*log(Nrb i )={13.67,17.49,17.32,23.11,18.73}(dBm).

[0099] Step 2: Calculate the receiving level deviation of the cellular user.

[0100] Step 2-1: For any cellular user Usr i ,i∈[1,m], calculate the path loss of its normal link

[0101] Step 2-2: Given the ideal receiving level value of a cellular user, calculate the receiving signal level RSPu of each cellular user i =Pul i -Lsus i ={-101.39,-85.13,-91.12,-86.38,-94.41}(dBm); calculate the Usr of the i-th cellular user i The receiving level deviation

[0102] Step 3: Filter cellular users that meet the qualification conditions as a qualified set based on D2D user pairs.

[0103] Step 3-1: Filter out all Ddus that meet the conditions based on three D2D user pairs j,i ≥DST th = 100 cellular users {{Usr1,Usr2,Usr5},{Usr1,Usr2,Usr3,Usr5},{Usr1,Usr3,Usr4}} are arranged in ascending order according to the D2D user pair subscripts and included in the jth D2D user pair Dpr j Qualified set Stok j In, Stok1={Usr1,Usr2,Usr5}, Stok2={Usr1,Usr2,Usr3,Usr5}, Stok3={Usr1,Usr3,Usr4}.

[0104] Step 3-2: Calculate the jth D2D user pair Dpr j The path loss

[0105] Step 4: Calculate the receiving level deviation of the D2D user pair.

[0106] Step 4-1: For the qualified set Stok of the jth D2D user pair j All cellular users k∈[1,jt ], where j t Dpr j The number of qualified cellular users owned by a user pair is used to calculate the number of resource blocks occupied by D2D user pairs Dpr j Multiplexed receive signal level:

[0107]

[0108] Step 4-2: Calculate the jth D2D user pair Dpr j The receiving level deviation

[0109] Step 5: Select corresponding cellular users as channel multiplexing objects of D2D user pairs according to preset judgment conditions.

[0110] Step 5-1: For the jth D2D user pair Dpr j , from the qualified set Stok j Filter out all the items that meet the conditions of cellular users Composition of multiplexing set Stmu j ={{Usr1},{""},{""}};

[0111] Step 5-2: The first D2D user pair Dpr1 satisfies the condition: multiplexing set Stmu j The number of elements Ns j ≥1, then select the cellular user Usr1 with the largest signal-to-noise ratio as the D2D user pair Dpr j Channel multiplexing object;

[0112] Step 5-3: The second D2D user pair Dpr2 and the third user pair Dpr3 satisfy the multiplexing set Stmu j Empty, that is, Ns j = 0, then from the qualified set Stok j The cellular user with the smallest receiving level deviation is selected as the D2D user for Dpr j The channel multiplexing objects are Usr2 and Usr3, and their minimum receiving level deviations are 0.06 and 0.14 respectively;

[0113] Step 5-4: The first D2D user reuses the Dpr1 channel as cellular user Usr1, occupies resource block {RB3}, and occupies the set Idle Set Therefore, the first D2D user reuses RB3 for Dpr1; the second D2D user reuses the Dpr2 channel as cellular user Usr2, occupying resource blocks {RB1, RB4, RB5}, occupying the set Idle Set So from the free set The largest numbered RB5 is selected and multiplexed to the second D2D user pair Dpr2; the third D2D user pair Dpr3 channel is multiplexed to the cellular user Usr3, occupying resource blocks {RB6, RB8} and occupying the set Idle Set From the free set RB8 with the largest number is selected and multiplexed to the third D2D user pair Dpr3.

[0114] The TMB-PC power control method of the D2D resource allocation method based on terminal mobility in the 5G system of the present invention is compared with the existing FCM fuzzy clustering (including power control and non-power control) level RDM-NPC random non-power control method on the MATLAB platform for simulation. The basic data information is shown in Table 3 above. The results are as follows: Figure 5 and Figure 6 shown.

[0115] like Figure 5 The relationship between system throughput and the number of cellular users is shown in Figure 1. In general, with the increase in the number of cellular users, the cell throughput shows a clear upward trend, but since the TMB-PC and FCM-PC methods add power control, the influence on the cell throughput is obvious, and their system indicators are obviously the most advantageous among the four methods. Among them, TMB-PC can dynamically allocate power according to the user's mobility status and the quality of the cell environment, which is better than the fuzzy clustering FCM-PC method in terms of throughput improvement; among the other two methods without power control, RDM-NPC is random, has the worst interference suppression ability, and has the lowest system performance.

[0116] like Figure 6 The system satisfaction is compared with the number of D2D user pairs. System satisfaction refers to the ratio of the number of D2D user pairs that meet the throughput standard corresponding to the currently allocated resource blocks to the number of all D2D user pairs. From the simulation results, it can be seen that the TMB-PC method of the present invention can dynamically track cellular users with different signal-to-noise ratios in real time and then allocate different powers. When seeking channel resource reuse for D2D user pairs, the criterion is also the minimum received signal level deviation, which ensures the optimal system satisfaction from another aspect. The random allocation RDM-NPC method has possible resource conflicts, and its satisfaction is also the worst.

[0117] The above embodiments are further elaborations and illustrations of the present invention for ease of understanding, and are not limitations of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A D2D resource allocation method based on terminal mobility in a 5G system, characterized in that: include: Allocate power to mobile terminals according to the moving speed of cellular users and calculate the receiving level deviation of cellular users; Based on the D2D user pairs, cellular users whose D2D user pair distance is greater than or equal to the distance threshold are screened as a qualified set, and the receiving level deviation of the D2D user pairs is calculated; Selecting cellular users whose receiving level deviation is greater than or equal to the receiving level deviation of the D2D user pair from the qualified set of D2D user pairs as a multiplexing set; If the reuse set of the D2D user pair is empty, the cellular user with the smallest receiving level deviation is selected from the qualified set as the channel reuse object of the D2D user pair; If it is not empty, the cellular user with the largest signal-to-noise ratio is selected from the reuse set as the channel reuse object of the D2D user pair.

2. According to claim 1, a D2D resource allocation method based on terminal mobility in a 5G system is characterized in that: The process of allocating power to the mobile terminal includes: Setting the full transmission power of the cellular cell and calculating the normal transmission power of the cellular cell based on the redundancy factor; Allocate initial multi-resource block power to the cellular user according to the moving speed of the cellular user; According to the signal-to-noise ratio of the cellular user, the final multi-resource block power and the final single resource block power are allocated to the cellular user.

3. A D2D resource allocation method based on terminal mobility in a 5G system according to claim 1 or 2, characterized in that: The calculation of the receiving level deviation of the cellular user comprises: Calculate the path loss of the cellular link for cellular users; The receiving level deviation of the cellular user is calculated according to the ideal receiving level value of the cellular user and the actual receiving signal level.

4. According to claim 1, a D2D resource allocation method based on terminal mobility in a 5G system is characterized in that: The screening process of the qualified set includes: Filter out the jth D2D user pair Dpr j Cellular users whose distance is greater than or equal to the distance threshold join Dpr j The qualified set of If all cellular users go to Dpr j If the distance between them is less than the distance threshold, then Dpr j The most distant cellular user joins Dpr j Qualified set.

5. A D2D resource allocation method based on terminal mobility in a 5G system according to claim 1 or 4, characterized in that: The calculating of the receiving level deviation of the D2D user comprises: Calculate the path loss of the D2D link of the D2D user; The receiving level deviation of the D2D user pair is calculated according to the ideal receiving level value of the D2D user pair and the receiving signal level of the cellular user resource blocks in the qualified set multiplexed by the D2D user pair.

6. A D2D resource allocation method based on terminal mobility in a 5G system according to claim 1, 2 or 4, characterized in that: Based on the jth D2D user pair Dpr j The receiving level deviation Pofd j , from D2D users to Dpr j The qualified set selects cellular users whose receiving level deviation is greater than or equal to Pofd j cellular users, forming the D2D user pair Dpr j The reuse set.

7. The D2D resource allocation method based on terminal mobility in a 5G system according to claim 2, characterized in that: The initial allocation of multiple resource block powers to cellular users includes: For the i-th cellular user Usr i , when its moving speed is greater than or equal to the speed threshold, the initial single resource block power is calculated based on the full power of the cellular cell transmission; When its moving speed is less than the speed threshold, the initial single resource block power is calculated based on the normal transmit power of the cellular cell; Initial multiple resource block powers are allocated based on the initial single resource block powers.

8. A D2D resource allocation method based on terminal mobility in a 5G system according to claim 2 or 7, characterized in that: For the i-th cellular user Usr i , when its signal-to-noise ratio is less than the signal-to-noise ratio threshold, the initial multi-resource block power of the cellular user is the final multi-resource block power; When the signal-to-noise ratio is greater than or equal to the signal-to-noise ratio threshold, the final multi-resource block power is corrected by a set elasticity coefficient; The final single resource block power is allocated based on the final multiple resource block powers.

9. The D2D resource allocation method based on terminal mobility in a 5G system according to claim 1, characterized in that: When the number of resource blocks occupied by the cellular user selected as the channel reuse object is greater than one, the resource blocks are divided into a resource block occupied set that has been reused by the D2D user and a resource block idle set that has not been reused; Corresponding resource blocks are allocated from the idle set of resource blocks to D2D user pairs for multiplexing.

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