CN102111773A - Space dynamic spectrum distribution method under urban heterogeneous wireless environment - Google Patents

Abstract

A space dynamic spectrum distribution method under urban heterogeneous wireless environment relates to a space dynamic spectrum distribution method, aiming to solve the problem that the real-time performance of dynamic spectrum distribution is bad in the conventional space dynamic spectrum distribution method. The method comprises the following steps: threshold is selected and divided into a hot spot area and a non-hot spot area according to spectrum requirement space distribution in an urban heterogeneous wireless network coverage area; uniform spectrum distribution is then performed according to the spectrum requirement space distribution, so as to meet the lowest spectrum requirement in the non-hot spot area; the remaining spectrum requirement of each district in the hot-spot area is calculated; the remaining spectrum quantity is calculated according to the spectrum total and the distributed spectrum quantity; and independent space dynamic spectrum distribution taking the districts as spatial granularity is simultaneously performed for each hot-spot area. The invention is applied to the space dynamic spectrum distribution under the urban heterogeneous wireless environment.

Description

Space dynamic frequency spectrum deployment method under the heterogeneous wireless environment of city

Technical field

The present invention relates to a kind of space dynamic frequency spectrum deployment method.

Background technology

The frequency spectrum resource method of salary distribution of wireless communication system is that fixed frequency spectrum is distributed at present, various wireless communication systems can only be worked on legal separately frequency band and cannot be illegally occupied other frequency spectrum resources, and the fixed frequency spectrum distribution makes each communication system not disturb separately mutually and effectively works.But because the fixed frequency spectrum distribution is to distribute according to the busy time-frequency spectrum demand of each wireless communication system, be in idle condition in off-peak hours with regard to a large amount of frequency spectrum resources is arranged, this has just caused a large amount of wastes of frequency spectrum resource.At the deficiency that fixed frequency spectrum is distributed, dynamic frequency spectrum deployment is suggested to improve the availability of frequency spectrum.The basic principle of dynamic frequency spectrum deployment is with sharing frequency spectrum resource, and at the skewness dynamic assignment frequency spectrum resource of spectrum requirement amount on time and space of each communication system, makes full use of limited frequency spectrum resources satisfying on the basis of spectrum requirement.Dynamic frequency spectrum deployment is divided into time dynamic frequency spectrum deployment and space dynamic frequency spectrum deployment, and the variation on time and space distributes frequency spectrum dynamically at spectrum requirement respectively.The spatial granularity of space dynamic frequency spectrum deployment has bigger influence to the performance of dynamic frequency spectrum deployment method, and the more little performance of spatial granularity is good more, is the method best performance of spatial granularity with the sub-district.Dynamic frequency spectrum deployment is actually optimization problem, and the reducing of spatial granularity increases the optimization problem scale, and the algorithm computational complexity causes algorithm to be difficult to requirement of real time with the non-linear increase of optimization problem scale.

Summary of the invention

The present invention is the relatively poor problem of dynamic frequency spectrum deployment real-time of solution existing space dynamic frequency spectrum deployment method, thereby the space dynamic frequency spectrum deployment method under the heterogeneous wireless environment of a kind of city is provided.

Space dynamic frequency spectrum deployment method under the heterogeneous wireless environment of city, it is realized by following steps:

Step 1, choose thresholding d according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city ₀For each sub-district in the heterogeneous wireless network overlay area, city: if the spectrum requirement total amount of this sub-district is more than or equal to described thresholding d ₀, then this microzonation is divided into M mutual non-conterminous hot spot region; If the spectrum requirement total amount of this sub-district is less than described thresholding d ₀, then this sub-district is defined as non-hot spot region; M is a positive integer;

Step 2, according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city, in whole overlay area, adopt uniform frequency spectrum distributing method to carry out spectrum allocation may, satisfy the minimum spectrum requirement of non-hot spot region, calculate the residual spectrum demand of each sub-district in the hot spot region then;

Step 3, according to frequency spectrum sum SP _TotalThe frequency spectrum quantity SP that has distributed _BasicCalculate residual spectrum quantity SP _Remainder, independently be the space dynamic frequency spectrum deployment of spatial granularity at parallel the carrying out in each hot spot region then with the sub-district.

Choose thresholding d according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city in the step 1 ₀Method be: the integral multiple according to the wireless network carrier bandwidth is enumerated from low to high, choose whole overlay area can be cut out M mutual non-conterminous hot spot region minimum threshold as thresholding d ₀

The method of calculating the residual spectrum demand of each sub-district in the hot spot region described in the step 2 is: according to concrete spectrum allocation schemes sp _{Basic, r},

With spectrum requirement spatial distribution matrix D (P, R), adopt formula:

i＝1～M

Calculate the unsatisfied additional frequency spectrum demand of residue of each sub-district among the Hotspot i of hot spot region

And additional frequency spectrum demand space distribution matrix D _Extra(P, R).

Beneficial effect: method of the present invention is by setting the thresholding of spectrum requirement total amount, space dynamic frequency spectrum deployment problem in the complete city wireless network coverage is decomposed, obtain the less dynamic frequency spectrum deployment problem of a plurality of scales after the decomposition, because computational complexity is with the non-linear relation of optimization problem scale, such dynamic frequency spectrum deployment PROBLEM DECOMPOSITION method can effectively reduce computational complexity, thereby under the prerequisite that does not reduce the dynamic frequency spectrum deployment performance, guarantee the real-time requirement of dynamic frequency spectrum deployment problem.

Description of drawings

Fig. 1 is a city intermediate frequency spectrum demand space distribution schematic diagram; Fig. 2 is that schematic diagram is divided in focus and non-hot spot region.

Embodiment

Space dynamic frequency spectrum deployment method under embodiment one, the city heterogeneous wireless environment, it is realized by following steps:

If the overlapping covering of multiple different radio access technologies (RAT) is arranged in the area of wireless network coverage territory, the RAT set R that all RAT constitute, r represents to gather element among the R, and the overlay area is made up of N sub-district, every sub-district b _nThe spectrum requirement quantity of interior different RAT is

Be that ((P R) is the two-dimensional matrix that each RAT spectrum requirement of expression distributes in the different districts to D to matrix D in whole overlay area for P, the R) element in.SP _TotalBe assignable frequency spectrum sum, the space dynamic frequency spectrum deployment for the frequency spectrum quantity that the different RAT in each sub-district distribute is

Be that ((P R) is the two-dimensional matrix that distributes among the different RAT of expression frequency spectrum resource different districts in whole overlay area to Sp to matrix S p for P, the R) element in.

Step 1, choose thresholding d according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city ₀For each sub-district in the heterogeneous wireless network overlay area, city: if the spectrum requirement total amount of this sub-district is more than or equal to described thresholding d ₀, then this microzonation is divided into M mutual non-conterminous hot spot region; If the spectrum requirement total amount of this sub-district is less than described thresholding d ₀, then this sub-district is defined as non-hot spot region; M is a positive integer;

In this step, be will (P R), chooses thresholding d according to spectrum requirement spatial distribution matrix D in the overlay area ₀With adjacent spectrum requirement total amount greater than d ₀The sub-district iris out and form M hot spot region Hotspot i, i=1～M, as shown in Figure 2, the spectrum requirement total amount is less than d ₀The sub-district form non-hot spot region.

Thresholding d described in this step ₀Choose and can enumerate from low to high according to the integral multiple of carrier bandwidths for each hot spot region being distinguished and alap threshold value, choose and whole overlay area can be cut out the minimum threshold of several non-conterminous hot spot regions as d ₀

Step 2, according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city, in whole overlay area, adopt uniform frequency spectrum distributing method to carry out spectrum allocation may, satisfy the minimum spectrum requirement of non-hot spot region, calculate the residual spectrum demand of each sub-district in the hot spot region then;

In this step, (P R), adopts uniform frequency spectrum distributing method to carry out dynamic frequency spectrum deployment in whole overlay area, with the least possible frequency spectrum quantity SP according to spectrum requirement spatial distribution matrix D _BasicThe spectrum requirement of non-hot spot region is met, this spectrum allocation may process at the right and wrong hot spot region, the therefore main here spectrum requirement satisfaction degree of considering non-hot spot region is then according to concrete spectrum allocation schemes sp _{Basic, r},

And D (P, R) the unsatisfied additional frequency spectrum demand of residue of each sub-district in the calculating hot spot region

I=1～M obtains additional frequency spectrum demand space distribution matrix D _Extra(P, R), wherein

i＝1～M。

Step 3, according to frequency spectrum sum SP _TotalThe frequency spectrum quantity SP that has distributed _BasicCalculate residual spectrum quantity SP _Remainder, independently be the space dynamic frequency spectrum deployment of spatial granularity at parallel the carrying out in each hot spot region then with the sub-district.

In this step, according to frequency spectrum sum SP _TotalThe frequency spectrum quantity SP that has distributed _BasicCalculate residual spectrum quantity SP _Remainder, SP _RemainderCan be used for satisfying the frequency spectrum quantity of hot spot region additional frequency spectrum demand exactly, then according to additional frequency spectrum demand space distribution matrix D _Extra(P is R) with usable spectrum quantity SP _RemainderTo M hot spot region Hotspot i, it is the spectrum allocation may of spatial granularity with the sub-district independently that i=1～M carries out respectively, obtains spectrum allocation schemes

This M carrying out that the spectrum allocation may problem can walk abreast is with further reduction algorithm operation time.

Obtain complete space dynamic frequency spectrum deployment scheme: Sp (P, R), wherein the spectrum allocation schemes of each sub-district is:

${\mathrm{sp}}_{b_n,r}=\left\{\begin{array}{cc}{\mathrm{sp}}_{\mathrm{basic},r}& \∀b_n\∉\mathrm{Hotspot\; i},i=1~M,\∀r\∈R\\ {\mathrm{sp}}_{\mathrm{basic},r}+{\mathrm{sp}}_{\mathrm{remainder},b_n,r}& \∀b_n\∈\mathrm{Hotspot\; i},i=1~M,\∀r\∈R\end{array}\right..$

Principle: to distribute be to be that the outwards tapered extension in center distributes with several focuses to operational space in the city, traffic carrying capacity in each sub-district is along with the increase of the distance of distance Hot Spot forms successively decrease (order from high to low is followed successively by mark 1, mark 2, mark 3, mark 4, mark 5) that negative exponent concerns, as shown in Figure 1.When the distance of a certain sub-district distance center Hot Spot was l (km), its traffic carrying capacity was P (r)=e with respect to the normalized value P (l) of center Hot Spot ^-l/k, wherein k is the form parameter of operational space distributed model, and the more little P of k (l) is fast more with the l decay, and taper is just sharp more.Because traffic carrying capacity and spectrum requirement are proportional, so the operational space distribution is equal to the spectrum requirement spatial distribution.By above-mentioned analysis, the spectrum requirement distribution that can sum up in the city has following characteristics: there are several focuses in the spatial distribution of spectrum requirement, and the high hot spot region of these spectrum requirements is separated by the low non-hot spot region of spectrum requirement.Therefore, make full use of the characteristics that city intermediate frequency spectrum demand space distributes, space dynamic frequency spectrum deployment problem in the complete city wireless network coverage is decomposed, obtain the less dynamic frequency spectrum deployment problem of a plurality of scales after the decomposition, thereby can effectively reduce computational complexity, requirement of real time.

Claims (3)

1. the space dynamic frequency spectrum deployment method under the city heterogeneous wireless environment, it is characterized in that: it is realized by following steps:

Step 1, choose thresholding d according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city ₀For each sub-district in the heterogeneous wireless network overlay area, city: if the spectrum requirement total amount of this sub-district is more than or equal to described thresholding d ₀, then this microzonation is divided into M mutual non-conterminous hot spot region; If the spectrum requirement total amount of this sub-district is less than described thresholding d ₀, then this sub-district is defined as non-hot spot region; M is a positive integer;

Step 2, according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city, in whole overlay area, adopt uniform frequency spectrum distributing method to carry out spectrum allocation may, satisfy the minimum spectrum requirement of non-hot spot region, calculate the residual spectrum demand of each sub-district in the hot spot region then;

Step 3, according to frequency spectrum sum SP _TotalThe frequency spectrum quantity SP that has distributed _BasicCalculate residual spectrum quantity SP _Remainder, independently be the space dynamic frequency spectrum deployment of spatial granularity at parallel the carrying out in each hot spot region then with the sub-district.

2. the space dynamic frequency spectrum deployment method under the heterogeneous wireless environment of city according to claim 1 is characterized in that choosing thresholding d according to the spectrum requirement spatial distribution in the heterogeneous wireless network overlay area, city in the step 1 ₀Method be: the integral multiple according to the wireless network carrier bandwidth is enumerated from low to high, choose whole overlay area can be cut out M mutual non-conterminous hot spot region minimum threshold as thresholding d ₀

3. the space dynamic frequency spectrum deployment method under the heterogeneous wireless environment of city according to claim 1 is characterized in that the method for the residual spectrum demand of each sub-district in the hot spot region of calculating described in the step 2 is: according to concrete spectrum allocation schemes s _{Pbasic, r}, With spectrum requirement spatial distribution matrix D (P, R), adopt formula:

I=1～M calculates the unsatisfied additional frequency spectrum demand of residue of each sub-district among the Hotspot i of hot spot region

And additional frequency spectrum demand space distribution matrix D _Extra(P, R).

Images