Terminal direct connection resource allocation method based on resource increment evaluation

Abstract

The invention discloses a terminal direct connection resource allocation method based on resource increment evaluation, and solves the problems of congestion of D2D user pairs and shortage of spectrum resources in existing communication. The method comprises the following steps: acquiring the number of resource blocks needing to be allocated by each D2D user at the current moment, and calculating the resource increment of each D2D user relative to the previous moment; selecting an operable user pair from the D2D user pairs according to a resource allocation condition; screening out effective users of each operable user pair according to the distance between the operable user pair and the cellular user; and obtaining the total interference between each D2D user pair, and selecting a cellular user of which the resource block margin meets the resource increment requirement and the interference requirement after multiplexing from the effective users as a target channel multiplexing object. According to the method, the perception of the cellular user and the D2D user pair can be optimally ensured while the interference is weakened, so that the spectrum resource utilization rate and the system performance of the 5G system are improved to the maximum extent.

Description

Technical Field

[0001] The present invention relates to the field of 5G communication technology, and in particular to a terminal direct resource allocation method based on resource increment evaluation. Background Art

[0002] The application of D2D (Device-to-Device) communication in 5G systems is becoming more and more popular. With the growth of user terminals, more and more D2D user pairs (including transmitters and receivers) will be crowded, and spectrum resources will become more scarce. Therefore, further improving the spectrum resource reuse rate of D2D user pairs and cellular users under the premise of studying the interference coordination of cellular D2D networks is an effective way to solve the spectrum resource problem. The more important research methods include power control, interference control, and dynamic resource allocation. Among these methods, interference control is the core. Power control is more effective but will increase the load of the 5G system accordingly. Dynamic resource allocation can evaluate the access of D2D user pairs in real time according to the system's resource margin, thereby keeping the system in a non-congested state, thereby improving user perception. It is an effective way to improve spectrum resource utilization without increasing the complexity of system operation. Summary of the invention

[0003] The present invention mainly solves the problems of D2D user congestion and spectrum resource shortage in existing communications, and provides a terminal direct resource allocation method based on resource increment evaluation.

[0004] The above technical problem of the present invention is mainly solved by the following technical solution: a terminal direct resource allocation method based on resource increment evaluation, comprising the following steps: Obtain the number of resource blocks that each D2D user needs to allocate at the current moment, and calculate the resource increment relative to the previous moment; Selecting an operable user pair from the D2D user pairs according to the resource allocation condition; Filter out valid users of each operable user pair according to the distance between the operable user pair and the cellular user; The total interference between each D2D user pair is obtained, and cellular users whose resource block margin after multiplexing meets the resource increment requirement and the interference requirement are selected from the valid users as the target channel multiplexing object.

[0005] The present invention starts with analyzing the service rates requested by each D2D user pair at different times, and converts the resource increments that need to be allocated; comprehensively evaluates whether the resource increments can meet the demand based on the system resource status; calculates the interference between D2D user pairs and the interference with cellular users, and screens out the cellular user set that can meet the resource increment; selects the target cellular users that can meet the interference requirements from the user set as the final multiplexed users, so as to achieve optimal perception of cellular users and D2D user pairs while weakening interference, thereby maximizing the spectrum resource utilization and system performance of the 5G system.

[0006] As a preferred solution, the resource increment of the D2D user relative to the previous moment is calculated, specifically including: The number of cellular user resource blocks reused by the D2D user pair at the previous moment is obtained, and the resource increment of the D2D user pair at the current moment is obtained according to the difference between the number of resource blocks required to be allocated at the current moment and the number of cellular user resource blocks reused at the previous moment.

[0007] The information about the number of cellular user resource blocks reused by the D2D user pair at the last moment can be obtained through the data recorded by the system. For the user pair that reused cellular user resource blocks at the last moment, the resource increment of the D2D user pair at the current moment is obtained by subtracting the number of cellular user resource blocks reused at the last moment from the number of resource blocks to be allocated at the current moment.

[0008] As a preferred solution, the selecting of operable user pairs from D2D user pairs according to the resource allocation condition specifically includes: Select D2D user pairs as operable user pairs if the number of resource blocks that the D2D user pairs need to allocate at the current moment is not greater than the upper limit of the resources applied for by the D2D user pairs and the resource increment of the D2D user pairs relative to the previous moment is not greater than the upper limit of the single resource increment of the D2D user pairs.

[0009] This step is to evaluate the resource increment demand of D2D users. The resource allocation conditions include that the number of resource blocks that a single D2D user pair needs to allocate at the current moment is not greater than the upper limit of the resource application of the D2D user pair, and the resource increment of a single D2D user pair relative to the previous moment is not greater than the upper limit of the single resource increment of the D2D user pair. If the above two conditions are met at the same time, it means that the resource application of the D2D user pair will be met, and these D2D user pairs are included in the D2D operation set as operable user pairs.

[0010] As a preferred solution, the method of screening out valid users of each operable user pair according to the distance between the operable user pair and the cellular user specifically includes: For an operable user pair, a cellular user whose distance to a cellular user is not less than a distance reference value is selected as a first valid user of the operable user pair.

[0011] In this solution, the first valid user is a valid user, and the first valid user of each operable user pair is screened out according to the distance between the operable user pair and the cellular user.

[0012] As a preferred solution, Calculate the mathematical expectation of the distance between any D2D user pair and all cellular users; Set the distance coefficient and use the product of the mathematical expectation value and the distance coefficient as the distance reference value.

[0013] The mathematical expectation value is the average value. The average value of the distance between the operable user and all cellular users is calculated and multiplied by a distance coefficient to obtain a base value for comparing the distance between the current operable user and the cellular user, namely, a distance reference value.

[0014] As a preferred solution, the cellular user that is operable to reuse resources at the last moment is regarded as the second valid user.

[0015] In this scheme, the second valid user, i.e., the valid user, preferably merges the operable user with the cellular user who reused resources at the previous moment, i.e., the second valid user, and the cellular user whose distance between the operable user and the cellular user is not less than the distance reference value, i.e., the first valid user, as the valid users of the current operable user.

[0016] As a preferred embodiment, the calculation of interference between each pair of D2D users specifically includes: Set the D2D transmission power, the path loss constant and path loss coefficient of the D2D link; According to the distance between each D2D user pair, the link loss between each D2D user pair is calculated. The link loss is the product of the path loss constant plus the path loss coefficient and the logarithmic function of the distance between two D2D user pairs. Calculate the interference between each D2D user pair, which is the difference between the D2D link transmission power and the link loss between each D2D user pair; The Boltzmann constant, Kelvin temperature, number of subcarriers, and subcarrier bandwidth are set, and the product of the Boltzmann constant, Kelvin temperature, number of subcarriers, and subcarrier bandwidth is converted into signal strength to obtain Gaussian white noise power spectrum density; Calculate the total interference between each D2D user pair under the white noise background.

[0017] As a preferred solution, an interference threshold is set, and for the second valid user, other D2D user pairs whose resources are multiplexed are obtained; Subtract the sum of resource blocks reused by the second valid user from the resource blocks occupied by the second valid user to obtain the remaining resource blocks after reuse; The second valid user whose resource block margin is not less than the resource increment and whose total interference is not greater than the interference threshold is regarded as the operable user to the final valid user.

[0018] The total interference compared with the interference threshold in this solution is the total interference between the operable user pair and other D2D user pairs.

[0019] As a preferred solution, for the first valid user, a D2D user pair whose resources are reused is obtained; Subtract the sum of resource blocks reused by the first valid user from the resource blocks occupied by the first valid user to obtain the remaining resource blocks after reuse; The first valid user whose resource block margin is not less than the number of resource blocks required to be allocated to the operable user pair and whose total interference is not greater than the interference threshold is taken as the final valid user of the operable user pair.

[0020] For the first valid user, this solution obtains all D2D user pairs whose resources are reused, adds up the number of resource blocks reused by other D2D user pairs using the current valid user's resources, and subtracts the total number of resource blocks reused by the current valid user from the resource blocks occupied by the current valid user to obtain the remaining resource blocks after the current valid user is reused. The resource increment requirement for the first valid user is that the remaining resource blocks are not less than the number of resource blocks that need to be allocated to the operable user pair, and the interference requirement is that the total interference between the operable user pair and the D2D user pair whose resources are reused by the valid user is not greater than the interference threshold. The valid user who meets the above two conditions is regarded as the final valid user of the operable user pair.

[0021] As a preferred solution, if there is a final valid user, the final valid user corresponding to the minimum total interference is selected as the final target resource reuse object; if there is no final valid user, the resource increment application of the operable user pair is rejected.

[0022] As a preferred solution, the carrying capacity of a single resource block and the number of resource blocks that need to be allocated at the current moment are calculated according to the service information of each D2D user.

[0023] As a preferred solution, the D2D user service information includes the D2D user's bit error rate and service signal-to-noise ratio at the current moment.

[0024] Calculate the decimal service signal-to-noise ratio according to the service signal-to-noise ratio, and calculate the bit error rate conversion value according to the bit error rate; divide the decimal service signal-to-noise ratio by the bit error rate conversion value, add one, and then calculate the logarithm to obtain the comprehensive process quantity; Set the number of subcarriers and subcarrier bandwidth occupied by a single resource block, and calculate the resource block bandwidth: number of subcarriers * subcarrier bandwidth / 1024; The single resource block carrying capacity is obtained by multiplying the resource block bandwidth and the comprehensive process quantity; Set the service rate that the D2D user applies for at the current moment; The service rate requested by the D2D user is divided by the carrying capacity of a single resource block and the result is rounded to the integer to obtain the number of resource blocks that need to be allocated at the current moment.

[0025] Therefore, the advantages of the present invention are: starting from analyzing the service rate applied for by each D2D user pair at different times, the resource increment that needs to be allocated is calculated; comprehensively evaluating whether the resource increment can meet the demand based on the system resource status; calculating the interference between D2D user pairs and the interference with cellular users, and screening out the cellular user set that can meet the resource increment; selecting the target cellular users who can meet the interference requirements from the user set as the final multiplexed users, so as to achieve the optimal guarantee of the perception of cellular users and D2D users while weakening the interference, thereby maximizing the spectrum resource utilization and system performance of the 5G system. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of a process of the present invention.

[0027] Figure 2 This is a comparison chart of system satisfaction between the present invention and other algorithms.

[0028] Figure 3 This is a comparison chart of the communication success probability of the present invention and other algorithms. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0030] Embodiment 1:

[0031] This embodiment provides a method for allocating terminal direct access resources based on resource increment evaluation, such as Figure 1 As shown, the following steps are included: Obtain the number of resource blocks that each D2D user needs to allocate at the current moment, and calculate the resource increment relative to the previous moment; Selecting an operable user pair from the D2D user pairs according to the resource allocation condition; Filter out valid users of each operable user pair according to the distance between the operable user pair and the cellular user; The total interference between each D2D user pair is obtained, and cellular users whose resource block margin after multiplexing meets the resource increment requirement and the interference requirement are selected from the valid users as the target channel multiplexing object.

[0032] As a preferred solution of this embodiment, obtaining the number of resource blocks that each D2D user needs to allocate at the current moment specifically includes: Obtain D2D user service information, including the current bit error rate and service signal-to-noise ratio of the D2D user.

[0033] The decimal service signal-to-noise ratio is calculated according to the service signal-to-noise ratio, and the bit error rate conversion value is calculated according to the bit error rate; the decimal service signal-to-noise ratio is divided by the bit error rate conversion value, the result is added by one, and then the logarithm is calculated to obtain the comprehensive process quantity.

[0034] Set the number of subcarriers and subcarrier bandwidth occupied by a single resource block, and calculate the resource block bandwidth: number of subcarriers * subcarrier bandwidth / 1024; 1024 is the value for conversion between units.

[0035] The single resource block carrying capacity is obtained by multiplying the resource block bandwidth by the comprehensive process quantity.

[0036] Set the service rate applied by the D2D user at the current moment; divide the service rate applied by the D2D user by the carrying capacity of a single resource block and round up to obtain the number of resource blocks that need to be allocated at the current moment.

[0037] As a preferred solution of this embodiment, calculating the resource increment of the D2D user relative to the previous moment specifically includes: The number of cellular user resource blocks reused by the D2D user pair at the previous moment is obtained, and the resource increment of the D2D user pair at the current moment is obtained according to the difference between the number of resource blocks required to be allocated at the current moment and the number of cellular user resource blocks reused at the previous moment.

[0038] The information about the number of cellular user resource blocks reused by the D2D user pair at the last moment can be obtained through the data recorded by the system. For the user pair that reused cellular user resource blocks at the last moment, the resource increment of the D2D user pair at the current moment is obtained by subtracting the number of cellular user resource blocks reused at the last moment from the number of resource blocks to be allocated at the current moment.

[0039] As a preferred solution of this embodiment, selecting an operable user pair from D2D user pairs according to a resource allocation condition specifically includes: Select D2D user pairs as operable user pairs if the number of resource blocks that the D2D user pairs need to allocate at the current moment is not greater than the upper limit of the resources applied for by the D2D user pairs and the resource increment of the D2D user pairs relative to the previous moment is not greater than the upper limit of the single resource increment of the D2D user pairs.

[0040] This step is to evaluate the resource increment demand of D2D users. The resource allocation conditions include that the number of resource blocks that a single D2D user pair needs to allocate at the current moment is not greater than the upper limit of the resource application of the D2D user pair, and the resource increment of a single D2D user pair relative to the previous moment is not greater than the upper limit of the single resource increment of the D2D user pair. If the above two conditions are met at the same time, it means that the resource application of the D2D user pair will be met, and these D2D user pairs are included in the D2D operation set as operable user pairs.

[0041] As a preferred solution of this embodiment, the valid users of each operable user pair are screened out according to the distance between the operable user pair and the cellular user, specifically including: Calculate the mathematical expectation of the distance between any D2D user pair and all cellular users; A distance coefficient is set, and the product of the mathematical expectation value and the distance coefficient is used as a reference value of the distance for the operable user.

[0042] The mathematical expectation value is the average value. The average value of the distance between the operable user and all cellular users is calculated and multiplied by a distance coefficient to obtain a base value for comparing the distance between the current operable user and the cellular user, namely, a distance reference value.

[0043] The distance information between each D2D user pair and all cellular users is obtained. For an operable user pair, a cellular user whose distance to the cellular user is not less than a distance reference value is selected as the first valid user of the operable user pair.

[0044] The cellular user that the operable user pair reused resources at the last moment is taken as the second valid user, and the first valid user and the second valid user are combined to form a valid user set.

[0045] The first valid user and the second valid user are both valid users. Preferably, the operable user pair, i.e., the second valid user, which is a cellular user that reused resources at the previous moment, and the cellular user whose distance between the operable user and the cellular user is not less than the distance reference value, i.e., the first valid user, are merged as valid users of the current operable user.

[0046] As a preferred solution of this embodiment, obtaining the total interference between each D2D user pair specifically includes: Set the D2D transmission power, the path loss constant and path loss coefficient of the D2D link; According to the distance between each D2D user pair, the link loss between each D2D user pair is calculated. The link loss is the product of the path loss constant plus the path loss coefficient and the logarithmic function of the distance between two D2D user pairs.

[0047] The interference between each D2D user pair is calculated as the difference between the D2D link transmission power and the link loss between each D2D user pair.

[0048] The Boltzmann constant, Kelvin temperature, number of subcarriers, and subcarrier bandwidth are set, and the product of the Boltzmann constant, Kelvin temperature, number of subcarriers, and subcarrier bandwidth is converted into signal strength to obtain Gaussian white noise power spectrum density; Calculate the total interference between each D2D user pair under the white noise background.

[0049] As a preferred solution of this embodiment, a cellular user whose resource block margin after multiplexing meets the resource increment requirement and meets the interference requirement is selected from valid users as a target channel multiplexing object, specifically including: An interference threshold is set, and for the second valid user, other D2D user pairs whose resources are multiplexed are obtained.

[0050] The resource blocks occupied by the second valid user are subtracted from the sum of the resource blocks reused to obtain the remaining resource blocks after reuse.

[0051] The second valid user whose resource block margin is not less than the resource increment and whose total interference is not greater than the interference threshold is regarded as the final valid user of the operable user pair. The total interference compared with the interference threshold in this solution is the total interference between the operable user pair and other D2D user pairs.

[0052] For the first valid user, a D2D user pair whose resources are reused is obtained.

[0053] The resource block occupied by the first valid user is subtracted from the sum of the resource blocks reused to obtain the remaining resource blocks after reuse.

[0054] The first valid user whose resource block margin is not less than the number of resource blocks required to be allocated to the operable user pair and whose total interference is not greater than the interference threshold is taken as the final valid user of the operable user pair.

[0055] In this solution, for the first valid user, all D2D user pairs whose resources are reused are obtained, the number of resource blocks reused by other D2D user pairs that reuse the resources of the current valid user is summed up, and the resource blocks occupied by the current valid user are subtracted from the total number of resource blocks reused by the resource blocks to obtain the remaining resource blocks after the current valid user is reused. The resource increment requirement for the first valid user is that the remaining resource blocks are not less than the number of resource blocks that need to be allocated to the operable user pair, and the interference requirement is that the total interference between the operable user pair and the D2D user pair whose resources are reused by the valid user is not greater than the interference threshold. The valid user who meets the above two conditions is regarded as the final valid user of the operable user pair.

[0056] The selected final valid user results are judged to determine whether there is a final valid user. If there is a final valid user, the final valid user corresponding to the minimum total interference is selected as the final target resource reuse object; if there is no final valid user, the resource increment application of this operable user pair is rejected.

[0057] The present invention starts with analyzing the service rates requested by each D2D user pair at different times, and converts the resource increments that need to be allocated; comprehensively evaluates whether the resource increments can meet the demand based on the system resource status; calculates the interference between D2D user pairs and the interference with cellular users, and screens out the cellular user set that can meet the resource increment; selects the target cellular users that can meet the interference requirements from the user set as the final multiplexed users, so as to achieve optimal perception of cellular users and D2D user pairs while weakening interference, thereby maximizing the spectrum resource utilization and system performance of the 5G system.

[0058] Embodiment 2:

[0059] This embodiment discloses a method for allocating terminal direct access resources based on resource increment evaluation. The method is described below using a specific formula. A single cell eNodeB and a single cell coverage area with m cellular users USR={Usr1, Usr2,…Usr m}, and there are n D2D user pairs DPR={Dpr1, Dpr2,…Dpr n}, the number of resource blocks occupied by each cellular user NRB={Nrb1, Nrb2,…Nrb m}, any D2D user to Dpr j ,j∈[1,n] and any cellular user Usr i , the distance Ddu of i∈[1,m] j,i (m), DDU = {Ddu j,i} is a j*i matrix, any D2D user pair Dpr j1 With Dpr j2 Distance Ddd j1,j2 (m), Dpr j At time t-1, multiplexing of cellular user Usr i Number of resource blocks Ndu j,t-1,i , the bit error rate BER at the current time t t ={Ber t,1 , Ber t,2 ,…Ber t,n}, the service signal-to-noise ratio SNR at the current time t t ={Snr t,1 , Snr t,2 ,…Snrt,n}(dB), and the service rate VTH requested at the current time t t ={Vth t,1 ,Vth t,2 ,…Vth t,n} (Mbps). The method steps include: S1. Obtain the number of resource blocks that each D2D user needs to allocate at the current moment, and calculate the resource increment relative to the previous moment.

[0060] S11. Obtain service information of the D2D user, including the current bit error rate and service signal-to-noise ratio of the D2D user.

[0061] Calculate the decimal service signal-to-noise ratio based on the service signal-to-noise ratio S m t,j =power(10, Snr t,j / 10), Where power() represents the power function.

[0062] Calculate the bit error rate conversion value based on the bit error rate BerT t,j =-ln(5* Ber t,j ) / 1.5, Where ln() represents the natural logarithm function.

[0063] Divide the decimal service signal-to-noise ratio by the bit error rate conversion value, add one, and then calculate the logarithm to obtain the comprehensive process quantity SRB t,j =log2(1+ SnrT t,j / BerT t,j ).

[0064] Set the number of subcarriers occupied by a single resource block Nm rb , subcarrier bandwidth Wd rb (kHz), calculate resource block bandwidth B RB =Nm rb *Wd rb / 1024(MHz).

[0065] Multiply the resource block bandwidth by the comprehensive process quantity to get the single resource block carrying capacity Vrst,j= B RB *SRB t,j (Mbps).

[0066] Set the service rate that the D2D user applies for at the current moment; divide the service rate that the D2D user applies for by the carrying capacity of a single resource block and round it up to get the number of resource blocks that need to be allocated at the current moment ARBt,j =Roundup(Vth t,j / Vrs t,j ,0), Among them, Roundup() represents the round-up function.

[0067] S12. Obtain the number of cellular user resource blocks reused by the D2D user at the previous moment, and calculate the resource increment requested by the D2D user at the current moment ΔR t,j =ARB t,j -Ndu j,t-1,i .

[0068] S2. Select an operable user pair from the D2D user pairs according to the resource allocation condition.

[0069] Set the upper limit R of resource application for a single D2D user mx , the upper limit of a single resource increment for a single D2D user is R tmx .

[0070] Select ARB t,j ≤R mx , and ΔR t,j ≤R tmx The D2D user pairs are taken as operable user pairs and included in the D2D operation set.

[0071] S3. Filter out valid users of each operable user pair according to the distance between the operable user pair and the cellular user.

[0072] S31. Calculate the mathematical expectation of the distance between any D2D user and all cellular users. DU J =∑ m i=1 Ddu j,i / m(m) Set the distance coefficient Ød∈[1,1.1], and use the product of the mathematical expectation value and the distance coefficient as the reference value of the operable user distance. DR j =Ød*DU J (m).

[0073] S32. Obtain the distance information between each D2D user pair and all cellular users, and for the operable user pair Dpr k , select Ddu k,i ≥DR k Cellular users Usr i , as the first valid user of the operable user pair, is included in the valid user set Sv k .

[0074] The operable user pair Usr of the cellular user that reused the resource at the last moment z As the second valid user, the first valid user and the second valid user are combined to form a valid user set Sv k .

[0075] S4. Obtain the total interference between each pair of D2D users, and select, from valid users, cellular users whose resource block margin after multiplexing meets the resource increment requirement and the interference requirement as target channel multiplexing objects.

[0076] S41. Set D2D transmit power Pwr d2d (dBm), the path loss constant Ct of the D2D link dd and path loss coefficient Cf dd ; According to the distance between each D2D user pair, the link loss between each D2D user pair is calculated. PcLos j1,j2 =Ct dd +Cf dd *log(Ddd j1,j2 / 1000)(dB).

[0077] Calculate D2D user pair Dpr j1 and Dpr j2 Interference between Int j1,j2 =Pwr d2d -PcLos j1,j2 (dB).

[0078] Set the Boltzmann constant K b (J / K), Kelvin temperature T k (K), number of subcarriers Nm rb , subcarrier bandwidth Wd rb , calculate the Gaussian white noise power spectral density Pp Gs =10*log(K b *T k *Nm rb *Wd rb *1024)+30(dBm / Hz), Calculate the total interference between each D2D user pair under white noise background InS j1,j2 =10*log(power(10, Pp Gs / 10)+power(10,Int j1,j2 / 10))(dB).

[0079] S42. Set the interference threshold Int th(dB), for the second valid user Usr z , that is, the cellular user that reuses resources at time t-1 can be operated to obtain the set of other D2D user pairs SDz={Dpr z1 , Dpr z2 ,…Dpr zx}; Subtract the sum of resource blocks reused by the second valid user from the resource blocks occupied by the resource blocks to obtain the remaining resource blocks after reuse. Sr z =Nrb z -∑ x y=1 Ndu zy,t-1,i .

[0080] Sr z ≥ΔR t,j And InS k,zy ≤Int th The second valid user Usr of (y=1,2,…,x) z As the final effective use, it is included in the final effective user set.

[0081] S43. For the first valid user Usr i (i is not equal to z), obtain the D2D user pair set SD whose resources are reused i ={Dpr i1 , Dpr i2 ,…Dpr ix}.

[0082] The resource block occupied by the first valid user is subtracted from the sum of the resource blocks reused to obtain the remaining resource blocks after reuse.

[0083] Sr i =Nrb i -∑ x y=1 Ndu iy,t-1,i .

[0084] Sr i ≥ARB t,k And InS k,iy ≤Int th The first valid user Usr of (y=1,2,…,x) i As the final effective use, it is included in the final effective user set.

[0085] S44. Determine whether there is a final valid user, If there is a final valid user, the final valid user corresponding to the minimum total interference is selected as the final target resource reuse object; If there is no final valid user, the resource increment application of the operable user will be rejected.

[0086] The method of the present invention is specifically described below using an example. Taking m=5 and n=3 as an example, the distribution of cellular users in a 5G cell is shown in Table 1:

[0087] Table 1 Distribution of cellular users The distribution of D2D user pairs in the 5G cell is shown in Table 2:

[0088] Table 2 Distribution of D2D user pairs The service deployment of D2D users distributed in the 5G cell is shown in Table 3:

[0089] Table 3 D2D user service development The basic data are shown in Table 4:

[0090] Table 4 Basic data This embodiment provides a method for allocating terminal direct access resources based on resource increment evaluation, including the following steps: S1. Obtain the number of resource blocks that each D2D user needs to allocate at the current moment, and calculate the resource increment relative to the previous moment.

[0091] S11. Obtain service information of the D2D user, including the current bit error rate and service signal-to-noise ratio of the D2D user.

[0092] Calculate the decimal service signal-to-noise ratio based on the service signal-to-noise ratio S m t,j =power(10, Snr t,j / 10)={3.16,0.5,1.35}.

[0093] Calculate the bit error rate conversion value based on the bit error rate BerT t,j =-ln(5* Ber t,j ) / 1.5={1.61,1.5,2.23}.

[0094] Calculate the comprehensive process quantity SRB t,j =log2(1+ SnrT t,j / BerT t,j ) ={1.57,0.42,0.68}.

[0095] Set the number of subcarriers occupied by a single resource block Nm rb , subcarrier bandwidth Wd rb (kHz), calculate resource block bandwidth B RB =Nm rb *Wd rb / 1024=0.352(MHz).

[0096] Multiply the resource block bandwidth by the comprehensive process quantity to get the single resource block carrying capacity Vrst,j= B RB *SRB t,j ={0.552,0.146,0.24} (Mbps).

[0097] Set the service rate that the D2D user applies for at the current moment; divide the service rate that the D2D user applies for by the carrying capacity of a single resource block and round it up to get the number of resource blocks that need to be allocated at the current moment ARB t,j =Roundup(Vth t,j / Vrs t,j ,0) ={2,7,4}.

[0098] S12. Obtain the number of cellular user resource blocks reused by the D2D user at the previous moment, and calculate the resource increment requested by the D2D user at the current moment ΔRt,j= ARB t,j -Ndu j,t-1,i ={1,5,3}.

[0099] S2. Select an operable user pair from the D2D user pairs according to the resource allocation condition.

[0100] Set the upper limit R of resource application for a single D2D user mx , the upper limit of a single resource increment for a single D2D user is R tmx .

[0101] Select ARB t,j ≤R mx , and ΔRt,j≤R tmx The D2D user pair is {Dpr1}, which is included in the D2D operation set as an operable user pair.

[0102] S3. Filter out valid users of each operable user pair according to the distance between the operable user pair and the cellular user.

[0103] S31. Calculate the mathematical expectation of the distance between any D2D user and all cellular users. DU J =∑m i=1 Ddu j,i / m={394,416, 460} (m) Set the distance coefficient Ød and calculate the distance reference value DR j =Ød*DU J ={425.52,449.28, 496.8} (m).

[0104] S32. Obtain the distance information between each D2D user pair and all cellular users, and for the operable user pair Dpr k=1 , select Ddu 1,i The cellular users {Usr4, Usr5} with ≥DR1=425.52 are included in the valid user set Sv1 as the first valid users of the operable user pair.

[0105] The cellular user Usr1 that reused resources at the last moment is taken as the second valid user, and the first valid user and the second valid user are combined to form a valid user set Sv1 = {Usr1, Usr4, Usr5}.

[0106] S4. Obtain the total interference between each pair of D2D users, and select, from valid users, cellular users whose resource block margin after multiplexing meets the resource increment requirement and the interference requirement as target channel multiplexing objects.

[0107] S41. Set D2D transmit power Pwr d2d (dBm), the path loss constant Ct of the D2D link dd and path loss coefficient Cf dd ; According to the distance between each D2D user pair, the link loss between each D2D user pair is calculated. PcLos j1,j2 =Ct dd +Cf dd *log(Ddd j1,j2 / 1000) ={120.04,134.13,131.19} (dB), Corresponding to PcLos 1,2 , PcLos 1,3 , PcLos 2,3 .

[0108] Calculate D2D user pair Dpr j1 and Dpr j2 Interference between Int j1,j2 =Pwr d2d -PcLosj1,j2 ={-97.04,-111.13,-108.19} (dB).

[0109] Set the Boltzmann constant K b (J / K), Kelvin temperature T k (K), number of subcarriers Nm rb , subcarrier bandwidth Wd rb , calculate the Gaussian white noise power spectral density Pp Gs =10*log(K b *T k *Nm rb *Wd rb *1024)+30=-118.31(dBm / Hz), Calculate the total interference between each D2D user pair under white noise background InS j1,j2 =10*log(power(10, Pp Gs / 10)+power(10,Int j1,j2 / 10)) ={-97.01,-110.13,-107.19} (dB), Corresponding to InS 1,2 , InS 1,3 , InS 2,3 .

[0110] S42. Set the interference threshold Int th (dB), there is only one operable user pair Dpr1, whose valid user set is {Usr1, Usr4, Usr5}. For the second valid user Usr1, only Dpr1 reuses its resource = 0, so SD1 is empty, but since Usr1 only occupies one resource of RB3, Sr is not satisfied. z =0≥ΔR t,j =1, therefore, Usr1 cannot be the final valid user.

[0111] S43. For the first valid user Usr i ={Usr4,Usr5}, First, for Usr4, the D2D user pair set SD4={Dpr2} that has been resource reused.

[0112] Calculating resource block margin Sr4=Nrb4-∑ x y=1 Ndu iy,t-1,4 =2.

[0113] Satisfy the condition Sr4=2≥ARBt,1 =2, the interference of Dpr1 and Dpr2 InS 1,2 =-97.01, does not satisfy InS 1,2 =-97.01≤Int th =-100(dB), therefore, Usr4 cannot be the final valid user.

[0114] For Usr5, the set of D2D user pairs that have been resource reused is SD4 = {Dpr3}.

[0115] Calculating resource block margin Sr3=Nrb3-∑ x y=1 Ndu iy,t-1,3 =1.

[0116] Satisfy the condition Sr3=2≥ARB t,1 = 2, interference of Dpr1 and Dpr3 InS 1,3 = -11.037, which satisfies InS 1,3 =-110.37≤Int th =-100(dB), therefore, Usr5 is the final effective user.

[0117] S44. Operable user Dpr k=1 The final valid user set is {Usr5}, only Dpr3 is reused, and there is no choice of minimum interference, so cellular user Usr5 can be directly used as Dpr k=1 The final target resource reuse object.

[0118] The following simulation experiment is used to illustrate the effect of the present invention. The method of the present invention (abbreviated as RIE-NPC non-power control method) is compared with the existing FCM fuzzy clustering power control method and RDM-NPC random non-power control method on the MATLAB platform. The basic data information is shown in Table 4 above, and the results are shown in Figures 2 to 3 shown.

[0119] like Figure 2The comparison between system satisfaction and the number of D2D user pairs is shown. System satisfaction refers to the ratio of the number of D2D user pairs that meet the throughput requirements in the currently allocated resource blocks to the number of all D2D user pairs. From the simulation results, it can be seen that the RIE-NPC method of the present invention can determine in real time whether the resource increment requested by D2D can be met according to the resource allocation status of the system, and calculate the interference between users at the same time. On the premise of satisfying the interference, the target multiplexed cellular users can be selected, and the system satisfaction can be evaluated from two dimensions: resource quantity and interference. Therefore, the performance is much better than the randomly allocated RDM-NPC non-power control method. Although FCM-PC is stronger than RIE-NPC in terms of satisfaction, it is based on sacrificing system performance. It is not applicable to the general situation where there are a large number of D2D users or large interference. like Figure 3 The relationship between the probability of successful communication and the number of D2D user pairs is shown. The system has the most reusable resources, the least interference between users, and the highest probability of successful communication. The communication probability of the RIE-NPC method of the present invention is equivalent to that of FCM-PC. The former relies on the identification of resource requirements, while the latter is achieved through power control. However, when the number of D2D users in the system increases, the superiority of the RIE-NPC of this method is reflected. The reason is that more users will lead to greater interference and require more powerful power control. However, the cell power is limited and the system load also has bottlenecks. Therefore, reviewing the resource demand is a better solution. The RDM-NPC method adopts a non-power control method of random resource allocation, so its probability of successful communication is the lowest. In addition, as the number of D2D reuse pairs increases, the probability of successful communication is gradually decreasing, and the method of the present invention also has the smallest decrease.

[0120] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A method for allocating terminal direct access resources based on resource increment evaluation, characterized in that: The following steps are involved: Obtain the number of resource blocks that each D2D user needs to allocate at the current moment, and calculate the resource increment relative to the previous moment; Selecting an operable user pair from the D2D user pairs according to the resource allocation condition; Filter out valid users of each operable user pair according to the distance between the operable user pair and the cellular user; The total interference between each D2D user pair is obtained, and cellular users whose resource block margin after multiplexing meets the resource increment requirement and the interference requirement are selected from the valid users as the target channel multiplexing object.

2. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 1, characterized in that: Calculate the resource increment of the D2D user relative to the previous moment, specifically including: The number of cellular user resource blocks reused by the D2D user pair at the previous moment is obtained, and the resource increment of the D2D user pair at the current moment is obtained according to the difference between the number of resource blocks required to be allocated at the current moment and the number of cellular user resource blocks reused at the previous moment.

3. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 1, characterized in that: The selecting of operable user pairs from D2D user pairs according to the resource allocation condition specifically includes: Select D2D user pairs as operable user pairs if the number of resource blocks that the D2D user pairs need to allocate at the current moment is not greater than the upper limit of the resources applied for by the D2D user pairs and the resource increment of the D2D user pairs relative to the previous moment is not greater than the upper limit of the single resource increment of the D2D user pairs.

4. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 1, characterized in that: The method of screening out valid users of each operable user pair according to the distance between the operable user pair and the cellular user specifically includes: Calculate the cellular user whose distance between any D2D user pair and the cellular user is not less than the distance reference value as the first valid user of the operable user pair.

5. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 4, characterized in that: For operable user pairs, calculate the mathematical expectation value of their distances relative to all cellular users; Set the distance coefficient and use the product of the mathematical expectation value and the distance coefficient as the distance reference value.

6. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 4, characterized in that: The cellular user that the operable user pair reused resources at the last moment is regarded as the second valid user.

7. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 6, characterized in that: An interference threshold is set, and for the second valid user, other D2D user pairs whose resources are multiplexed are obtained; Subtract the sum of resource blocks reused by the second valid user from the resource blocks occupied by the second valid user to obtain the remaining resource blocks after reuse; The second valid user whose resource block margin is not less than the resource increment and whose total interference is not greater than the interference threshold is regarded as the operable user to the final valid user.

8. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 7, characterized in that: For the first valid user, obtain its D2D user pair reused by resources; Subtract the sum of resource blocks reused by the first valid user from the resource blocks occupied by the first valid user to obtain the remaining resource blocks after reuse; The first valid user whose resource block margin is not less than the number of resource blocks required to be allocated to the operable user pair and whose total interference is not greater than the interference threshold is taken as the final valid user of the operable user pair.

9. The method for allocating terminal direct access resources based on resource increment evaluation according to claim 8, characterized in that: If there is a final valid user, the final valid user corresponding to the minimum total interference is selected as the final target resource reuse object; if there is no final valid user, the resource increment application of the operable user pair is rejected.

10. A method for allocating terminal direct access resources based on resource increment evaluation according to any one of claims 1 to 6, characterized in that: The single resource block carrying capacity and the number of resource blocks that need to be allocated at the current moment are calculated based on the service information of each D2D user.

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