CN105517002A - Interference-suppression and energy-saving cellular network relay station deployment method - Google Patents

Abstract

The invention discloses an interference-suppression and energy-saving cellular network relay station deployment method, which aims at problems that the traditional cellular network has high energy loss, high base station apparatus costs and low energy efficiency. The interference-suppression and energy-saving cellular network relay station deployment method comprises the steps: firstly, according to position distribution of users, determining position coordinates and quantity of candidate relay stations by utilizing a K-means algorithm; drawing an interference figure of the candidate relay stations; constructing a basic model which can maximize energy efficiency under limitation conditions of deployment budget, spectrum efficiency and interference threshold distance; performing relay station optimal deployment selection by utilizing a greedy selection way; finally determining the positions and quantity of the relay stations. The interference-suppression and energy-saving cellular network relay station deployment method can be applied to cellular relay network, and can directly deploy a new relay station on a desired place, thereby reducing the total energy loss of the communication system, and meanwhile, ensuring the system capacity and the user service quality; the interference-suppression and energy-saving cellular network relay station deployment method can be further applied to deploying other sites of the cellular network, such as micro NodeBs and femtocells.

Description

A kind of AF panel and energy-conservation Cellular Networks relay station dispositions method

Technical field

The present invention relates to wireless communication technology field, especially relate to a kind of AF panel and energy-conservation Cellular Networks relay station dispositions method.

Background technology

The fast development of wireless network is that the life of people is provided convenience, but the huge energy consumption that the communications industry produces also can not be ignored.The energy resource consumption of Information & Communication Technology becomes focal issue.Show according to correlative study, the energy consumption of ICT probably occupies the CO2 emissions in the whole world 2%.Particularly base station energy consumption accounts for 60% ~ 80% of cellular network total energy consumption.Traditional cellular network can not meet the demand of number of users at present and service traffics.Therefore, in order to reduce cellular network energy consumption, and in conjunction with the direction that current cellular networks super-intensive is disposed, introduce low-power consumption in a wireless communication system, the relay station of low cost is necessary.

Under the call of ICT industry energy-saving and emission-reduction, the concept of " green communications " is arisen at the historic moment, and it is intended to the total energy consumption reducing communication system, ensures the service quality of power system capacity and mobile subscriber simultaneously.This emerging trend of raising realizing energy efficiency has in cellular networks promoted standardization authorities and the continuous Probe into Future power-saving technology of Virtual network operator, to improve network performance.Some technology have been suggested or have been applied, such as, adopt advanced physical-layer techniques, as MIMO, OFDM, cognitive radio, network code and collaboration communication etc.; Design the new network architecture, as heterogeneous network, spaced antenna, multi-hop honeycomb etc.; Employing wireless electricity and network resource management mechanism, as different cross-layer optimization algorithm, dynamic power saving, the coordination of multi-path radio access technology etc.; Based on estimated flow load, adopt community zoom technology, dynamic base-station dormancy to reach energy-conservation object.Since VanderMeulen proposes the theory of wireless relay channel, the deployment of relay station obtains larger concern and research.Guo etc. analyze the quantity of relay station and position to the impact of power system capacity, and demonstrate the capacity that Optimization deployment can improve indoor user 60% and outdoor user 38%.Chang and Lin proposes a kind of effective base station and relay station associating deployment scheme, makes network throughput, disposes the entirety of budget and system and cover and reach balance balance.In addition, Chang etc. also proposed a kind of relay station deployment scheme based on cluster newly, consider network throughput simultaneously, dispose the balance of the entirety covering of budget and system.Lu etc. propose throughput-maximized relay station deployment issue, and this problem is proved to be NP-difficulty, and propose a greedy heuritic approach, for this problem provides suboptimal solution.

But, the lifting that research lays particular emphasis on throughput and covering mostly disposed by the relay station in early stage, and the decline problem of the energy efficiency that the increase that have ignored energy consumption causes, for the deployment scenario of Cellular Networks relay station, seldom combine and consider that interference between spectrum efficiency, lower deployment cost budget, interference between base station and relay station or relay station is on the impact of energy efficiency.

Energy consumption for legacy cellular net is large, the problem that base station equipment cost is high and energy efficiency is low, the deployment of relay station is considered to dispose symmetrically mostly, but be difficult to accomplish to dispose symmetrically in practical application scene, because frequency spectrum is very rare, in order to improve system spectral efficiency, relay station in same community and base station or often use identical frequency band between relay station and relay station, this will cause intra-cell interference, the methods such as conventional power control are difficult to accomplish not only to improve spectrum efficiency but also effectively suppress the interference between relay station, the more important thing is, under the condition considering interference and lower deployment cost, do not reach the dynamic equilibrium of spectrum efficiency and energy efficiency.

Summary of the invention

For the deficiency of above-mentioned technology, the invention provides a kind of AF panel and energy-conservation Cellular Networks relay station dispositions method, the method can realize the random placement carrying out relay station according to the position distribution of user, according to lower deployment cost budget, while effectively inhibit the interference between relay station, reach the dynamic equilibrium of spectrum efficiency and energy efficiency, in lower deployment cost budget, under co-channel interference between relay station and the condition of spectrum efficiency, maximum energy efficiency, determine fixed relay station location and the quantity of selection, reduce the energy consumption of Cellular Networks, reduce base station equipment cost and improve energy efficiency.

The technical scheme realizing the object of the invention is as follows:

AF panel and an energy-conservation Cellular Networks relay station dispositions method, comprise the steps:

1) abscissa of all candidate relay of initialization and ordinate, namely wherein n is the number of candidate relay;

2) calculating is determined and the user that each initial candidate relay station is connected;

3) the relative users coordinate that certain iteration belongs to a kth groove is calculated;

4) to step 3) in all user coordinates in a kth groove sue for peace, then average;

5) according to position coordinates and the quantity of obtained candidate relay, then in conjunction with predefined interference threshold distance value d _t, set up the interference figure between candidate relay, the distance when between two relay stations is less than d _t, then think to there is interference between these two relay stations, the distance when between two relay stations is greater than d _t, then think to there is not interference between these two relay stations.

6) basic model of maximum energy efficiency is set up;

7) position and the quantity of the greedy way selection relay station disposed is adopted;

By above step, in conjunction with the co-channel interference between spectrum efficiency, candidate relay and lower deployment cost, under the model of maximum energy efficiency, N can be obtained _rspectrum efficiency under individual relay station deployment conditions and energy efficiency, from this N _rin spectrum efficiency under individual relay station deployment conditions and energy efficiency, select to meet η _sEthe deployment way of maximum energy efficiency while>=τ, finally can obtain maximum energy efficiency under the restrictive condition disposing budget, spectrum efficiency and interference threshold distance, to determine selected repeating station spacing and quantity, to realize suppressing interference and the deployment of energy-conservation Cellular Networks relay station.

Step 1) in, abscissa and the ordinate at initial relay station are respectively:

$R_{k_x}=\mathrm{\Δ}Rcos\left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+x_B---\left(1\right)$

$R_{k_y}=\mathrm{\Δ}R\sin \left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+y_B---\left(2\right)$

In formula, Δ R is the distance of initial candidate relay station distance base station, and n is the number of groove, is also the number of candidate relay, can choose, k=1,2 according to actual conditions ..., n represents a kth groove, x _band y _babscissa and the ordinate of base station respectively.

Step 2) in, according to the user profile that user's poisson process that is that to obey intensity be λ and home location register store, user location distribution figure in an observing time section can be obtained, utilize K-means algorithm user to be assigned in n groove, the candidate relay namely belonged in this groove of user distance in certain groove is nearest.According to point groove number n, a K-means function representation in community be:

$min\underset{k=1}{\overset{n}{\Σ}}\left|X_i-R_k\right|,\∀X_i\∈C_k---\left(3\right)$

In formula, C _krepresent a kth groove, X _ithe coordinate of user i, R _kthe position coordinates of a kth initial candidate relay station, represent the coordinate of the user i belonged to arbitrarily in a kth groove, user in groove can be obtained thus and, to the minimum range of a kth initial candidate relay station, namely find all users be connected with each initial candidate relay station accordingly.

Step 3) in, in order to create equally distributed groove, the distance of each candidate relay and all users must be calculated, user joins corresponding groove according to the minimum range between candidate relay, when carrying out the t time iteration, if k is nearest for user i distance candidate relay, then user i will add a kth groove, belongs to C _kall user coordinates computational methods be:

$C_k^{\left(t\right)}=\left\{\begin{array}{cc}{X}_i:\left|X_i-R_k^{\left(t\right)}\right|\≤\left|X_i-R_{k*\backslash k}^{\left(t\right)}\right|& \∀k^{*}=1,2,...,n\end{array}\right\}---\left(4\right)$

In formula, represent kth groove during the t time iteration, X _ithe coordinate of user i, the position coordinates of kth candidate relay when being the t time iteration, when being the t time iteration except a kth candidate relay position coordinates of remaining candidate relay.

Step 4) in, each user can only add a groove, when user being assigned to after in corresponding groove, next the user coordinates that certain iteration belongs in respective grooves is sued for peace, then average, as the coordinate of new candidate relay, constantly carry out iteration, obtain the coordinate of the candidate relay that iteration each time obtains, until the coordinate of candidate relay no longer changes or the difference of coordinate is less than an accuracy value ε, then iteration terminates, and can obtain the position coordinates of final candidate relay

$R_k^{(t+1)}=\frac{{\mathrm{\ΣX}}_i}{\left|C_k^{\left(t\right)}\right|},\∀X_i\∈C_k^{\left(t\right)}---\left(5\right)$

In formula, t is the number of times of iteration, be the candidate relay position coordinates of the t time iteration gained, X _ithe coordinate of user i, Σ X _irepresent and the user coordinates belonged in a kth groove sued for peace, the total number of users amount that the t time iteration falls in a kth groove, represent the coordinate of the user i belonged to arbitrarily in a kth groove, represent kth groove during the t time iteration.The condition that iteration terminates is:

$R_k^{(t+1)}-R_k^{\left(t\right)}\≤\mathrm{\ϵ}---\left(6\right)$

In formula, be the difference of the candidate relay position coordinates of the t time iteration gained and the candidate relay position coordinates of the t-1 time iteration gained, ε is accuracy value.

Position due to certain user is constantly change, choose the user distribution in multiple observing time, solve according to above method, obtain the coordinate of the candidate relay in each observing time, finally the coordinate of the relay station in repeatedly observing time is averaged, obtain the position coordinates of metastable candidate relay.

Step 6) in, in a community, all relay stations share a frequency band to improve the availability of frequency spectrum, neighbor cell uses different frequency bands, channeling can be considered in non-conterminous community, and the relay station that method described like this can expand to multiple cell is disposed, and can cause co-channel interference each other when relay station transmits simultaneously, in order to avoid or the interference that reduces between relay station, the distance between any two relay stations must be greater than a predefined interference threshold distance value d _t, because lower deployment cost is limited, the cost of the relay station of institute subordinate within deployment budget space, must be wanted the lifting cell throughout of maximum possible simultaneously, ensures the spectrum efficiency of system.In addition, spectrum efficiency is defined as the ratio of throughput and bandwidth, and energy efficiency is defined as the ratio of throughput and power consumption, and system bandwidth used is W.

The total throughout of system is

$R=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·R_{C_k}+R_B---\left(7\right)$

In formula, represent the throughput of a kth candidate relay, RS _ka binary variable, represent the total throughout of selected all candidate relay, R _brepresent the total throughout of all users be connected with base station;

The total power consumption of system is

$P=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}---\left(8\right)$

In formula, represent in the quantity of disposing the selected candidate relay of budget limitations, be set to N _r; Δ _band Δ _rrepresent the power amplification efficiency of base station and relay station respectively, P _band P _rrepresent the transmitting power of base station and relay station respectively, P _b0and P _r0represent the quiescent dissipation of base station and relay station respectively.

Based on the above condition, the basic model of maximum energy efficiency is:

maxη _EE

$\begin{array}{cc}s.t.& \left\{\begin{array}{c}{\mathrm{\η}}_{SE}\≥\mathrm{\τ}\\ \underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·{\mathrm{DC}}_{RS}\≤{\mathrm{TD}}_b\\ \begin{array}{cc}{d}_{{\mathrm{kk}}^{*}}>d_T& \∀k,k^{*}\∈(1,n),k\≠k^{*}\end{array}\end{array}\right.\end{array}$

In formula, for system energy efficiency, for system spectral efficiency, τ is the desired value of system spectral efficiency, represent in the quantity of disposing the selected candidate relay of budget limitations, be N _r, DC _rSthe lower deployment cost of each relay station, TD _balways dispose budget, k and k ^*represent any two relay stations, represent any two selected candidate relay k and candidate relay k ^*between distance, d _tit is predefined interference threshold distance value.

Step 7) in, the coverage of candidate relay is certain, supposes that the covering radius of each candidate relay is R _r, in order to ensure spectrum efficiency η _sE>=τ, for the selection of candidate relay, is defined as follows criterion:

First consider to select to cover the more candidate relay of user, the candidate relay that namely throughput is larger;

Secondly the distance between candidate relay is considered, namely the interference between candidate relay, on the impact of systematic function, can also be taked the mode needing to introduce the deployment of relay station greediness of maximum energy efficiency, select position and the quantity of relay station, greedy mode of disposing, comprises the steps:

A: select the relay station that in community, in candidate relay, throughput is maximum, be designated as C ₁, a spectrum efficiency during calculating deployment relay station and energy efficiency, i.e. N _rwhen=1, ${\mathrm{\η}}_{SE}=\frac{R_{C_1}+R_B}{W},{\mathrm{\η}}_{EE}=\frac{R_{C_1}+R_B}{({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}},$ Then residue lower deployment cost TD is upgraded _b-DC _rSn _rif not, zero, then perform second step;

B: remove and C ₁there is the candidate relay of interference, the relay station selecting throughput larger from remaining candidate relay, is designated as C ₂, spectrum efficiency during calculating deployment two relay stations and energy efficiency, i.e. N _rwhen=2, continue to upgrade residue lower deployment cost TD _b-DC _rSn _rif not, zero, then the selection of other candidate relay on the basis that candidate relay is above selected by that analogy, the spacing of relay station must be greater than d between two _tto ensure there is not interference between relay station, until residue lower deployment cost TD _b-DC _rSn _rtill≤0.

Beneficial effect

The invention provides a kind of AF panel and energy-conservation Cellular Networks relay station dispositions method, the method can realize the random placement carrying out relay station according to the position distribution of user, while meeting lower deployment cost budget and effectively limit suppress to disturb between relay station, determine selected candidate relay station location and quantity, reach the dynamic equilibrium of spectrum efficiency and energy efficiency, in addition, this dispositions method can also expand to the deployment of other Cellular Networks websites, such as micro-base station, Home eNodeB.

Accompanying drawing explanation

Fig. 1 is the operational flowchart of the method for the invention

Fig. 2 is the initial condition figure of Cellular Networks

Fig. 3 is the iteration stable diagram of Cellular Networks

Fig. 4 is the interference figure between the candidate relay of Cellular Networks

Fig. 5 is that the greediness of Cellular Networks relay station disposes the operational flowchart selected

Embodiment

Below in conjunction with drawings and Examples, content of the present invention is further described, but is not limitation of the invention.

Embodiment:

AF panel and an energy-conservation Cellular Networks relay station dispositions method, comprise the steps:

1) abscissa of all candidate relay of initialization and ordinate, namely wherein n is the number of candidate relay;

2) calculating is determined and the user that each initial candidate relay station is connected;

3) the relative users coordinate that certain iteration belongs to a kth groove is calculated;

4) to step 3) in all user coordinates in a kth groove sue for peace, then average;

5) according to position coordinates and the quantity of obtained candidate relay, then in conjunction with predefined interference threshold distance value d _t, set up the interference figure between candidate relay, the distance when between two relay stations is less than d _t, then think to there is interference between these two relay stations, the distance when between two relay stations is greater than d _t, then think to there is not interference between these two relay stations.

6) basic model of maximum energy efficiency is set up;

7) position and the quantity of the greedy way selection relay station disposed is adopted;

By above step, in conjunction with the co-channel interference between spectrum efficiency, candidate relay and lower deployment cost, under the model of maximum energy efficiency, N can be obtained _rspectrum efficiency under individual relay station deployment conditions and energy efficiency, from this N _rin spectrum efficiency under individual relay station deployment conditions and energy efficiency, select to meet η _sEthe deployment way of maximum energy efficiency while>=τ, finally can obtain maximum energy efficiency under the restrictive condition disposing budget, spectrum efficiency and interference threshold distance, to determine selected repeating station spacing and quantity, to realize suppressing interference and the deployment of energy-conservation Cellular Networks relay station.

Step 1) in, abscissa and the ordinate at initial relay station are respectively:

$R_{k_x}=\mathrm{\Δ}Rcos\left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+x_B---\left(1\right)$

$R_{k_y}=\mathrm{\Δ}Rsin\left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+y_B---\left(2\right)$

In formula, Δ R is the distance of initial candidate relay station distance base station, and n is the number of groove, is also the number of candidate relay, can choose, k=1,2 according to actual conditions ..., n represents a kth groove, x _band y _babscissa and the ordinate of base station respectively.

Step 2) in, according to the user profile that user's poisson process that is that to obey intensity be λ and home location register store, user location distribution figure in an observing time section can be obtained, utilize K-means algorithm user to be assigned in n groove, the candidate relay namely belonged in this groove of user distance in certain groove is nearest.According to point groove number n, a K-means function representation in community be:

$min\underset{k=1}{\overset{n}{\Σ}}\left|X_i-R_k\right|,\∀X_i\∈C_k---\left(3\right)$

In formula, C _krepresent a kth groove, X _ithe coordinate of user i, R _kthe position coordinates of a kth initial candidate relay station, represent the coordinate of the user i belonged to arbitrarily in a kth groove, user in groove can be obtained thus and, to the minimum range of a kth initial candidate relay station, namely find all users be connected with each initial candidate relay station accordingly.

Step 3) in, in order to create equally distributed groove, the distance of each candidate relay and all users must be calculated, user joins corresponding groove according to the minimum range between candidate relay, when carrying out the t time iteration, if k is nearest for user i distance candidate relay, then user i will add a kth groove, belongs to C _kall user coordinates computational methods be:

$C_k^{\left(t\right)}=\left\{\begin{array}{cc}{X}_i:\left|X_i-R_k^{\left(t\right)}\right|\≤\left|X_i-R_{k*\backslash k}^{\left(t\right)}\right|& \∀k^{*}=1,2,...,n\end{array}\right\}---\left(4\right)$

In formula, represent kth groove during the t time iteration, X _ithe coordinate of user i, the position coordinates of kth candidate relay when being the t time iteration, when being the t time iteration except a kth candidate relay position coordinates of remaining candidate relay.

Step 4) in, each user can only add a groove, when user being assigned to after in corresponding groove, next the user coordinates that certain iteration belongs in respective grooves is sued for peace, then average, as the coordinate of new candidate relay, constantly carry out iteration, obtain the coordinate of the candidate relay that iteration each time obtains, until the coordinate of candidate relay no longer changes or the difference of coordinate is less than an accuracy value ε, then iteration terminates, and can obtain the position coordinates of final candidate relay

$R_k^{(t+1)}=\frac{{\mathrm{\ΣX}}_i}{\left|C_k^{\left(t\right)}\right|},\∀X_i\∈C_k^{\left(t\right)}---\left(5\right)$

In formula, t is the number of times of iteration, be the candidate relay position coordinates of the t time iteration gained, X _ithe coordinate of user i, Σ X _irepresent and the user coordinates belonged in a kth groove sued for peace, the total number of users amount that the t time iteration falls in a kth groove, represent the coordinate of the user i belonged to arbitrarily in a kth groove, represent kth groove during the t time iteration.The condition that iteration terminates is:

$R_k^{(t+1)}-R_k^{\left(t\right)}\≤\mathrm{\ϵ}---\left(6\right)$

In formula, be the difference of the candidate relay position coordinates of the t time iteration gained and the candidate relay position coordinates of the t-1 time iteration gained, ε is accuracy value.

Position due to certain user is constantly change, choose the user distribution in multiple observing time, solve according to above method, obtain the coordinate of the candidate relay in each observing time, finally the coordinate of the relay station in repeatedly observing time is averaged, obtain the position coordinates of metastable candidate relay.

Step 6) in, in a community, all relay stations share a frequency band to improve the availability of frequency spectrum, neighbor cell uses different frequency bands, channeling can be considered in non-conterminous community, and the relay station that method described like this can expand to multiple cell is disposed, and can cause co-channel interference each other when relay station transmits simultaneously, in order to avoid or the interference that reduces between relay station, the distance between any two relay stations must be greater than a predefined interference threshold distance value d _t, because lower deployment cost is limited, the cost of the relay station of institute subordinate within deployment budget space, must be wanted the lifting cell throughout of maximum possible simultaneously, ensures the spectrum efficiency of system.In addition, spectrum efficiency is defined as the ratio of throughput and bandwidth, and energy efficiency is defined as the ratio of throughput and power consumption, and system bandwidth used is W.

The total throughout of system is

$R=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·R_{c_k}+R_B---\left(7\right)$

In formula, represent the throughput of a kth candidate relay, RS _ka binary variable, represent the total throughout of selected all candidate relay, R _brepresent the total throughout of all users be connected with base station;

The total power consumption of system is

$P=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}---\left(8\right)$

In formula, represent in the quantity of disposing the selected candidate relay of budget limitations, be set to N _r; Δ _band Δ _rrepresent the power amplification efficiency of base station and relay station respectively, P _band P _rrepresent the transmitting power of base station and relay station respectively, P _b0and P _r0represent the quiescent dissipation of base station and relay station respectively.

Based on the above condition, the basic model of maximum energy efficiency is:

maxη _EE

$\begin{array}{cc}s.t.& \left\{\begin{array}{c}{\mathrm{\η}}_{SE}\≥\mathrm{\τ}\\ \underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·{\mathrm{DC}}_{RS}\≤{\mathrm{TD}}_b\\ \begin{array}{cc}{d}_{{\mathrm{kk}}^{*}}>d_T& \∀k,k^{*}\∈(1,n),k\≠k^{*}\end{array}\end{array}\right.\end{array}$

In formula, for system energy efficiency, for system spectral efficiency, τ is the desired value of system spectral efficiency, represent in the quantity of disposing the selected candidate relay of budget limitations, be N _r, DC _rSthe lower deployment cost of each relay station, TD _balways dispose budget, k and k ^*represent any two relay stations, represent any two selected candidate relay k and candidate relay k ^*between distance, d _tit is predefined interference threshold distance value.

Step 7) in, the coverage of candidate relay is certain, supposes that the covering radius of each candidate relay is R _r, in order to ensure spectrum efficiency η _sE>=τ, for the selection of candidate relay, is defined as follows criterion:

First consider to select to cover the more candidate relay of user, the candidate relay that namely throughput is larger;

Secondly the distance between candidate relay is considered, namely the interference between candidate relay, on the impact of systematic function, can also be taked the mode needing to introduce the deployment of relay station greediness of maximum energy efficiency, select position and the quantity of relay station, greedy mode of disposing, comprises the steps:

A: select the relay station that in community, in candidate relay, throughput is maximum, be designated as C ₁, a spectrum efficiency during calculating deployment relay station and energy efficiency, i.e. N _rwhen=1, then residue lower deployment cost TD is upgraded _b-DC _rSn _rif not, zero, then perform second step;

B: remove and C ₁there is the candidate relay of interference, the relay station selecting throughput larger from remaining candidate relay, is designated as C ₂, spectrum efficiency during calculating deployment two relay stations and energy efficiency, i.e. N _rwhen=2, continue to upgrade residue lower deployment cost TD _b-DC _rSn _rif not, zero, then the selection of other candidate relay on the basis that candidate relay is above selected by that analogy, the spacing of relay station must be greater than d between two _tto ensure there is not interference between relay station, until residue lower deployment cost TD _b-DC _rSn _rtill≤0.

As shown in Figure 1:

A () determines position coordinates and the quantity of candidate relay, then set up the interference figure between candidate relay in conjunction with predefined interference threshold distance;

(b) build can under the restrictive condition disposing budget, spectrum efficiency and interference threshold distance the basic model of maximum energy efficiency;

C () adopts greedy selection mode to carry out the selection of relay station Optimization deployment

As shown in Figure 2, be the initial condition figure of base station cell net.

As shown in Figure 3, the relay station pointed by arrow represent successive ignition stablize after the position of candidate relay, its calculation procedure comprises step 2), step 3), step 4).

As shown in Figure 4, the summit of interference figure represents relay station, and the limit of interference figure represents exists interference between relay station between two, if two summits do not connect, then thinks to there is not interference between these two relay stations.By the position distribution of n candidate relay, can calculate the distance arbitrarily between two between relay station, the distance when between two relay stations is less than d _t, then think to there is interference between these two relay stations, the distance when between two relay stations is greater than d _t, then think to there is not interference between these two relay stations, thus the interference figure between relay station can be set up.

As shown in Figure 5, the method specifically comprises:

Step S101, according to the candidate relay list obtained after iteration, calculates the user throughput in each relay coverage;

Step S102, selects the relay station that in community, in candidate relay, throughput is maximum, is designated as C ₁, a spectrum efficiency during calculating deployment relay station and energy efficiency, i.e. N _rwhen=1, ${\mathrm{\η}}_{SE}=\frac{R_{C_1}+R_B}{W},{\mathrm{\η}}_{EE}=\frac{R_{C_1}+R_B}{({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}};$

Step S103, disposes budget according to total and disposed relay station quantity, upgrades residue lower deployment cost TD _b-DC _rSn _r;

Step S104, if residue lower deployment cost TD _b-DC _rSn _r> 0, then perform step S105; If residue lower deployment cost TD _b-DC _rSn _r≤ 0, then perform step step S106;

Step S105, removes and C ₁there is the candidate relay of interference, the relay station selecting throughput larger from remaining candidate relay, is designated as C ₂, spectrum efficiency during calculating deployment two relay stations and energy efficiency, i.e. N _rwhen=2, perform step S103 and step S104, upgrade residue lower deployment cost TD _b-DC _rSn _rif not, zero, then the selection of other candidate relay on the basis that candidate relay is above selected by that analogy, until step S106 remains lower deployment cost TD _b-DC _rSn _rtill≤0;

Step S106, when meeting TD _b-DC _rSn _rwhen≤0, then relay station is disposed and is selected to terminate.

By above step, in conjunction with the co-channel interference between spectrum efficiency, candidate relay and lower deployment cost, under the model of maximum energy efficiency, N can be obtained _rspectrum efficiency under individual relay station deployment conditions and energy efficiency, from this N _rin spectrum efficiency under individual relay station deployment conditions and energy efficiency, select to meet η _sEthe deployment way of maximum energy efficiency while>=τ, finally can obtain maximum energy efficiency under the restrictive condition disposing budget, spectrum efficiency and interference threshold distance, to determine selected repeating station spacing and quantity, to realize suppressing interference and the deployment of energy-conservation Cellular Networks relay station.

Claims (8)

1. AF panel and an energy-conservation Cellular Networks relay station dispositions method, is characterized in that, comprise the steps:

1) abscissa of all candidate relay of initialization and ordinate, namely wherein n is the number of candidate relay;

2) calculating is determined and the user that each initial candidate relay station is connected;

3) the relative users coordinate that certain iteration belongs to a kth groove is calculated;

4) to step 3) in all user coordinates in a kth groove sue for peace, then average;

5) interference figure between candidate relay is set up, according to position coordinates and the quantity of the candidate relay obtained after iteration, then in conjunction with predefined interference threshold distance value d _t, obtain the interference figure between candidate relay;

6) basic model of maximum energy efficiency is set up;

7) position and the quantity of the greedy way selection relay station disposed is adopted.

2. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, is characterized in that, step 1) in, abscissa and the ordinate at initial relay station are respectively:

$R_{k_x}=\mathrm{\Δ}Rcos\left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+x_B---\left(1\right)$

$R_{k_y}=\mathrm{\Δ}Rsin\left(\frac{2\mathrm{\π}}{n}\right(k+1\left)\right)+y_B---\left(2\right)$

Wherein Δ R is the distance of initial candidate relay station distance base station, and n is the number of groove, is also the number of candidate relay, can choose, k=1,2 according to actual conditions ..., n represents a kth groove, x _band y _babscissa and the ordinate of base station respectively.

3. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, it is characterized in that, step 2) in, according to the user profile that user's poisson process that is that to obey intensity be λ and home location register store, user location distribution figure in an observing time section can be obtained, utilize K-means algorithm user to be assigned in n groove, the candidate relay namely belonged in this groove of user distance in certain groove is nearest.According to point groove number n, a K-means function representation in community be:

$\begin{array}{cc}min\underset{k=1}{\overset{n}{\Σ}}|X_i-R_k|,& \∀X_i\∈C_k\end{array}---\left(3\right)$

In formula, C _krepresent a kth groove, X _ithe coordinate of user i, R _kthe position coordinates of a kth initial candidate relay station, represent the coordinate of the user i belonged to arbitrarily in a kth groove, user in groove can be obtained thus and, to the minimum range of a kth initial candidate relay station, namely find all users be connected with each initial candidate relay station accordingly.

4. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, it is characterized in that, step 3) in, in order to create equally distributed groove, must calculate the distance of each candidate relay and all users, user joins corresponding groove according to the minimum range between candidate relay, when carrying out the t time iteration, if k is nearest for user i distance candidate relay, then user i will add a kth groove.Belong to C _kall user coordinates computational methods be:

$C_k^{\left(t\right)}=\left\{\begin{array}{cc}{X}_i:|X_i-R_k^{\left(t\right)}|\≤|X_i-R_{k^{*}\backslash k}^{\left(t\right)}|& \∀k^{*}=1,2,...,n\end{array}\right\}---\left(4\right)$

In formula, represent kth groove during the t time iteration, X _ithe coordinate of user i, the position coordinates of kth candidate relay when being the t time iteration, when being the t time iteration except a kth candidate relay position coordinates of remaining candidate relay.

5. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, it is characterized in that, step 4) in, each user can only add a groove, when user being assigned to after in corresponding groove, next the user coordinates that certain iteration belongs in respective grooves is sued for peace, then average, as the coordinate of new candidate relay, constantly carry out iteration, obtain the coordinate of the candidate relay that iteration each time obtains, until the coordinate of candidate relay no longer changes or the difference of coordinate is less than an accuracy value ε, then iteration terminates, the position coordinates of final candidate relay can be obtained

$\begin{array}{cc}{R}_k^{(t+1)}=\frac{{\mathrm{\ΣX}}_i}{\left|C_k^{\left(t\right)}\right|},& \∀X_i\∈C_k^{\left(t\right)}\end{array}---\left(5\right)$

In formula, t is the number of times of iteration, be the candidate relay position coordinates of the t time iteration gained, X _ithe coordinate of user i, Σ X _irepresent and the user coordinates belonged in a kth groove sued for peace, the total number of users amount that the t time iteration falls in a kth groove, represent the coordinate of the user i belonged to arbitrarily in a kth groove, represent kth groove during the t time iteration, the condition that iteration terminates is:

$R_k^{(t+1)}-R_k^{\left(t\right)}\≤\mathrm{\ϵ}---\left(6\right)$

In formula, be the difference of the candidate relay position coordinates of the t time iteration gained and the candidate relay position coordinates of the t-1 time iteration gained, ε is accuracy value;

Position due to certain user is constantly change, the user distribution in multiple observing time can be chosen, obtain the coordinate of the candidate relay in each observing time, finally the coordinate of the relay station in repeatedly observing time is averaged, the position coordinates of metastable candidate relay can be obtained.

6. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, it is characterized in that, step 6) in, in a community, all relay stations share a frequency band to improve the availability of frequency spectrum, neighbor cell uses different frequency bands, channeling can be considered in non-conterminous community, the relay station that method described like this can expand to multiple cell is disposed, co-channel interference can be caused each other when relay station transmits simultaneously, in order to avoid or the interference that reduces between relay station, distance between any two relay stations must be greater than a predefined interference threshold distance value d _tbecause lower deployment cost is limited, the cost of the relay station of institute subordinate must within deployment budget space, want the lifting cell throughout of maximum possible simultaneously, ensure the spectrum efficiency of system, in addition, spectrum efficiency is defined as the ratio of throughput and bandwidth, energy efficiency is defined as the ratio of throughput and power consumption, and system bandwidth used is W

The total throughout of system is

$R=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·R_{C_k}+R_B---\left(7\right)$

In formula, k=1,2 ... n represents the throughput of a kth candidate relay, RS _ka binary variable,

represent the total throughout of selected all candidate relay, R _brepresent the total throughout of all users be connected with base station;

The total power consumption of system is

$P=\underset{k=1}{\overset{n}{\Σ}}{\mathrm{RS}}_k\·({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}---\left(8\right)$

In formula, represent in the quantity of disposing the selected candidate relay of budget limitations, be set to N _r; Δ _band Δ _rrepresent the power amplification efficiency of base station and relay station respectively, P _band P _rrepresent the transmitting power of base station and relay station respectively, P _b0and P _r0represent the quiescent dissipation of base station and relay station respectively,

Based on the above condition, the basic model of maximum energy efficiency is:

maxη _EE

$\begin{array}{cc}s.t.& \left\{\begin{array}{c}{\mathrm{\η}}_{SE}\≥\mathrm{\τ}\\ \underset{k=1}{\overset{n}{\Σ}}R{S}_k\·D{C}_{RS}\≤T{D}_b\\ \begin{array}{cc}{d}_{{\mathrm{kk}}^{*}}>d_T& \∀k,k^{*}\∈(1,n),k\≠k^{*}\end{array}\end{array}\right.\end{array},$

Wherein, for system energy efficiency, for system spectral efficiency, τ is the desired value of system spectral efficiency, represent in the quantity of disposing the selected candidate relay of budget limitations, be N _r, DC _rSthe lower deployment cost of each relay station, TD _balways dispose budget, k and k ^*represent any two relay stations, represent any two selected candidate relay k and candidate relay k ^*between distance, d _tit is predefined interference threshold distance value.

7. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, is characterized in that, step 7) in, the coverage of candidate relay is certain, supposes that the covering radius of each candidate relay is R _r, in order to ensure spectrum efficiency η _sE>=τ, for the selection of candidate relay, is defined as follows criterion:

First consider to select to cover the more candidate relay of user, the candidate relay that namely throughput is larger;

Secondly consider the distance between candidate relay, the interference namely between candidate relay, on the impact of systematic function, can also be taked the mode needing to introduce the deployment of relay station greediness of maximum energy efficiency, select position and the quantity of relay station.

8. AF panel according to claim 1 and energy-conservation Cellular Networks relay station dispositions method, is characterized in that, the mode that described greediness is disposed, and comprises the steps:

A: select the relay station that in community, in candidate relay, throughput is maximum, be designated as C ₁, a spectrum efficiency during calculating deployment relay station and energy efficiency, i.e. N _rwhen=1, ${\mathrm{\η}}_{SE}=\frac{R_{C_1}+R_B}{W},$ ${\mathrm{\η}}_{EE}=\frac{R_{C_1}+R_B}{({\mathrm{\Δ}}_R{P}_R+P_{R0})+{\mathrm{\Δ}}_B{P}_B+P_{B0}},$ Then residue lower deployment cost TD is upgraded _b-DC _rSn _rif not, zero, then perform second step;

B: remove and C ₁there is the candidate relay of interference, the relay station selecting throughput larger from remaining candidate relay, is designated as C ₂, spectrum efficiency during calculating deployment two relay stations and energy efficiency, i.e. N _rwhen=2, continue to upgrade residue lower deployment cost TD _b-DC _rSn _rif not, zero, then the selection of other candidate relay on the basis that candidate relay is above selected by that analogy, the spacing of relay station must be greater than d between two _tto ensure there is not interference between relay station, until residue lower deployment cost TD _b-DC _rSn _rtill≤0.