CN104768185A - Trade-off method for interference elimination and energy harvesting of two-layer heterogeneous network - Google Patents

Abstract

The invention discloses a trade-off method for interference elimination and energy harvesting of a two-layer heterogeneous network. The downlink of the two-layer heterogeneous network comprises L macrocell base stations, M macrocell user terminals, N Femtocell base stations and F Femtocell user terminals. According to the method, based on the signal to noise ratio between the Femtocell user terminals and the macrocell user terminals, the interference power of the downlink, and interference alignment feasibility condition, the interference elimination and energy harvesting mode is effectively optimized according to the real-time downlink transmission environment of the two-layer heterogeneous network, the coverage rate and reliability of the indoor communication environment are improved, and network energy efficiency is improved.

Description

The interference elimination of two-layer heterogeneous network and energy acquisition compromise algorithm

Technical field

The present invention relates to the information transmission under a kind of two-layer heterogeneous network, interference is eliminated and energy-collecting method, particularly relate in a kind of Femtocell network downstream link based on interference alignment interference elimination and energy acquisition compromise algorithm, belong to wireless communication technology field.

Background technology

There are some researches show about have the enterprise customer of 30% and the domestic consumer of 45% to be faced with poor indoor communications environments in recent years.But along with the application of various new multimedia services and high speed data transfers business, people improve in the urgent need to indoor wireless communication network coverage environment, also have higher requirement to capability of wireless communication system and message transmission rate.

Flying honeycomb (Femtocell) and can provide good in-door covering rate and higher message transmission rate due to low cost, receives the concern of many people in the industry gradually.Since 3GPP promulgates relaease 8, fly honeycomb and be namely defined as the employing physical-layer techniques identical with macrocellular.The Arranging principles different according to it, this by macrocellular with fly the two-layer heterogeneous network that honeycomb forms and can provide good solution for in-door covering.But that can predict along with this two-layer heterogeneous network scale and business tine is growing, not only can introduce comparatively serious interference problem, also can cause problems of energy consumption to a certain degree.Interference alignment techniques effectively can eliminate interference, but in wireless transmission process, interference eradicating efficacy is very easily subject to actual channel state impact.Now, although this signal processing consumes the effect that system resource still likely cannot reach expectation.PulkitGrover and Anant Sahai in 2010 IEEE International Symposium on Information TheoryProceedings publish thesis " shannon meets tesla:wireless information and power transfer " show that wireless communication system can obtain the dual gain of information and Energy Transfer simultaneously.Therefore, how to provide one and be applicable to two-layer heterogeneous network communication environment, and the interference elimination method with high energy efficiency communication feature has great importance.

Summary of the invention

The object of the present invention is to provide a kind of interference elimination and energy acquisition compromise algorithm of two-layer heterogeneous network, improve coverage rate and the reliability of indoor communications environments, promote network energy efficiency.

Object of the present invention is achieved by the following technical programs:

The interference elimination of two-layer heterogeneous network and an energy acquisition compromise algorithm,

Described two-layer heterogeneous network down link comprises L macrocell base stations, a M macrocell user terminal, N number ofly flies cellular basestation, and F flies cellular user terminal, L>=1, M>=1, N>=1,1≤F≤4; Each macrocell base stations antenna number is T _l, respectively flying cell-site antenna number is T _n, respectively flying cellular user terminal antenna number is T _f, each macrocell user terminal antenna number is T _m, above-mentioned all number of antennas are all more than or equal to 1;

The method mainly comprises following steps:

Step one: initialization information is mutual, collects and obtains two-layer heterogeneous network base station ownership, antenna configuration, frequency, position, adjacent area parameter information; Collect the radio spatial channels state information between each layer user terminal and base station;

Step 2: set up two-layer isomery and fly cellular network downlink received signal model, in the downlink transmission of two-layer heterogeneous network, be positioned at the n-th (n ∈ { 1, N}) individual f (the f ∈ { 1 flying cellular access point overlay area,, F}) individual fly cellular user terminal place receive signal vector be expressed as:

$Y_n^f=H_n^{\mathrm{fn}}{X}_n^f+\underset{p\≠f}{\overset{F}{\underset{p=1}{\mathrm{\Σ}}}}{H}_n^{\mathrm{fn}}{X}_n^p+\underset{i\≠n}{\overset{N}{\underset{i=1}{\mathrm{\Σ}}}}\underset{p=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{fi}}{X}_i^p+\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{H}_l^{\mathrm{fl}}{X}_l^m+Z_n^f$

Be positioned at l (l ∈ 1 ..., L}) individual macrocell base stations overlay area m (m ∈ 1 ..., M}) and the signal vector that receives of individual macrocell user end is expressed as:

$Y_l^m=H_l^{\mathrm{ml}}{X}_l^m+\underset{q\≠m}{\overset{M}{\underset{q=1}{\mathrm{\Σ}}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{j\≠l}{\overset{L}{\underset{j=1}{\mathrm{\Σ}}}}\underset{q=1}{\overset{M}{\mathrm{\Σ}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}\underset{f=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{mi}}{X}_i^f+Z_l^m$

represent and be under the jurisdiction of the Received signal strength that the n-th f of flying cellular basestation flies cellular user terminal, be f the desired signal flying cellular user terminal, represent the white Gaussian noise being under the jurisdiction of the n-th f of flying cellular basestation and flying cellular user terminal and receive, represent f the interference from same community flying cellular user terminal and receive, represent f the same layer interference flying honeycomb from other flying cellular user terminal and receive, represent that macrocell base stations flies the cross-layer interference of cellular user terminal to f; represent the Received signal strength being under the jurisdiction of m macrocell user terminal of l macrocell base stations, represent the desired signal of m macrocell user terminal, represent the white Gaussian noise that m macrocell user terminal receives, be m macrocell user terminal receive from same area interference, the same layer interference from other macrocellulars that m macrocell user terminal receives, represent that flying cellular basestation disturbs the cross-layer of m macrocell user terminal; X _n, X _i, X _land X _jrepresent n-th respectively, i (n, i ∈ 1 ..., N}) fly cellular basestation and l, j (l, j ∈ 1 ..., L}) and the transmission signal of individual macrocell base stations, further represent that xth to fly cellular basestation or the xth macrocell base stations T to y user terminal _x× 1 dimensional signal, T _xfor xth flies cellular basestation or an xth macrocell base stations antenna number; represent n-th respectively, i flies cellular basestation and l macrocell base stations to the individual channel condition information flying cellular user terminal of f; represent that l, j macrocell base stations and i-th fly the channel condition information of cellular basestation to m macrocell user terminal respectively;

Step 3: calculate the signal to noise ratio of m macrocell user terminal received signal that the n-th f flying cellular basestation overlay area to fly cellular user terminal, a l macrocell base stations overlay area

Step 4: based on signal to noise ratio described in step 3 and each user terminal threshold value comparative result is adjudicated, if signal to noise ratio is greater than threshold value, interference described in administration step five is eliminated, if signal to noise ratio is less than threshold value, and energy acquisition described in administration step ten;

Step 5: user terminal obtains the hierarchical information of each unit in heterogeneous network and interference user channel condition information, the same layer interference in the final Received signal strength of macrocell user terminal adopts frequency division means to eliminate;

Step 6: calculate the two-layer heterogeneous network that interference occurs and whether meet interference alignment feasibility condition, to make in two-layer heterogeneous network down link macrocell user terminal and flies cellular user terminal and have identical degree of freedom d;

①T _L-M×d≥0,T _N-F×d≥0,T _M-d≥0,T _F-d≥0

② $\left\{\begin{array}{c}\underset{l:(l,n)\∈I}{\mathrm{\Σ}}(T_L-\mathrm{Md})\mathrm{Md}+\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}(F_d-d)d\≥2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\mathrm{Fd}\underset{k\∈K_n}{\mathrm{\Σ}}d\\ \max \{\underset{l\∈I_A}{\mathrm{\Σ}}{T}_L,\underset{i\∈I_B}{\mathrm{\Σ}}{T}_N,\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}{T}_F\}\≥\underset{l\∈I_A}{\mathrm{\Σ}}d+\underset{i\∈I_B}{\mathrm{\Σ}}d+\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}d\end{array}\right.$

③ $\left\{\begin{array}{c}\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}(T_M-d)d\≥\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\mathrm{Md}\underset{k\∈K_l}{\mathrm{\Σ}}d\\ \max \{\underset{i\∈I_E}{\mathrm{\Σ}}{T}_N,\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}{T}_M\}\≥\underset{i\∈I_E}{\mathrm{\Σ}}d+\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}d\end{array}\right.$

In formula, K _nbe the n-th random subset flying to fly in cellular basestation overlay area cellular user terminal set, K _lit is the random subset of macrocell user terminal set in l macrocell base stations; I represents all random subset producing the set of two different districts of interference, I _a, I _frepresent the random subset of macrocell base stations, I _b, I _c, I _erepresent the random subset flying cellular basestation, and formula 2. middle I _b, I _cwithout occuring simultaneously;

For fly cellular user terminal and macrocell user terminal should make its feasibility condition meet respectively formula 1., 2. with formula 1., 3., to ensure the transmitting of desired signal, all kinds of interference of reasonable elimination, now, as meet above-mentioned feasibility condition then administration step seven interference eliminate, if meet; the energy acquisition of administration step ten;

Step 7: calculate that the f flying cellular basestation overlay area with n-th is individual to fly transmitting terminal corresponding to cellular user terminal and disturb pre-coding matrix and the transmitting terminal corresponding with m macrocell user terminal of l macrocell base stations overlay area disturbs pre-coding matrix

Step 8: calculate n-th and to fly in cellular basestation overlay area f and fly the same layer of cellular user terminal, cross-layer dl interference power approximation m macrocell user terminal cross-layer dl interference power approximation in l macrocell base stations overlay area and respectively with threshold value compare; Wherein, the mark of tr (A) representing matrix A;

If dl interference power is less than threshold value, the interference of administration step nine is eliminated, if dl interference power is greater than threshold value, and the energy acquisition of administration step ten;

Step 9: calculate f and fly cellular user terminal and m macrocell user terminal interference cancellation matrix with complete interference and eliminate rear administration step 11;

Step 10: calculate n-th and fly the individual energy acquisition information flying m macrocell user terminal in cellular user terminal, a l macrocell base stations overlay area of f in cellular basestation overlay area and respectively with threshold value compare;

If energy acquisition information is greater than threshold value, complete administration step 11 after energy acquisition, if energy acquisition information is less than threshold value, directly administration step 11;

Step 11: epicycle interference is eliminated and terminated with energy acquisition process, waits for that next cyclic process starts.

Object of the present invention can also be realized further by following technical measures:

The interference elimination of aforementioned two-layer heterogeneous network and energy acquisition compromise algorithm, the pre-coding matrix of step 7 in distributed iterative interference alignment techniques pre-coding matrix initial value is respectively any T _f× d, T _m× d ties up unitary matrice.

The interference elimination of aforementioned two-layer heterogeneous network and energy acquisition compromise algorithm, step 9 is specially calculating n-th and flies in cellular basestation overlay area f and fly cellular user terminal interference cancellation matrix m macrocell user end user terminal in l macrocell base stations overlay area the pre-coding matrix of each user and interference cancellation matrix is made to meet following concerns mandate:

The interference elimination of aforementioned two-layer heterogeneous network and energy acquisition compromise algorithm, when the total number of users of target is less than or equal to three, wherein step 9 is solving employing classical interference alignment techniques in V, U process needed for interference alignment.

The interference elimination of aforementioned two-layer heterogeneous network and energy acquisition compromise algorithm, when the total number of users no requirement (NR) of target, wherein step 9 solve interference alignment needed for V, U process in adopt distributed iterative disturb alignment techniques.

Compared with prior art, the invention has the beneficial effects as follows: align feasibility condition for criterion to fly the signal to noise ratio of cellular user terminal and macrocell user terminal, dl interference power and interference, descending real-time Transmission environment based on two-layer heterogeneous network is effectively optimized its interference elimination and energy acquisition pattern, improve coverage rate and the reliability of indoor communications environments, promote network energy efficiency.

Accompanying drawing explanation

Fig. 1 is system model figure of the present invention;

Fig. 2 is that interference of the present invention is eliminated and energy acquisition flow chart.

Embodiment

Below in conjunction with the drawings and specific embodiments, the invention will be further described.

System model figure of the present invention as shown in Figure 1.Two-layer heterogeneous network down link in figure comprises L macrocell base stations 1, a M macrocell user terminal 2, N number of cellular basestation 3, F that flies fly cellular user terminal 4 and router five.Meanwhile, consider that two-layer heterogeneous network down link the actual scene of interference occurs and flies the actual formulation situation of cellular standards, can L >=1 be made, M >=1, N >=1,1≤F≤4.The each macro base station antenna number of further hypothesis is T _l, respectively flying cell-site antenna number is T _n, respectively flying cellular user terminal antenna number is T _f, each macrocell user terminal antenna number is T _m, wherein all number of antennas are all more than or equal to 1.

The present invention mainly solves the optimization problem of interference elimination under two-layer heterogeneous network and energy acquisition.

The method mainly comprises following steps:

Step one: initialization information is mutual, collects and obtains two-layer heterogeneous network radio configuration parameters information, channel condition information.

Step 2: set up two-layer isomery and fly cellular network downlink received signal model.In the downlink transmission of two-layer heterogeneous network, be positioned at n-th (n ∈ 1 ..., N}) individual fly cellular basestation overlay area f (f ∈ 1 ..., F}) individual fly cellular user terminal place receive signal vector can be expressed as:

$Y_n^f=H_n^{\mathrm{fn}}{X}_n^f+\underset{p\≠f}{\overset{F}{\underset{p=1}{\mathrm{\Σ}}}}{H}_n^{\mathrm{fn}}{X}_n^p+\underset{i\≠n}{\overset{N}{\underset{i=1}{\mathrm{\Σ}}}}\underset{p=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{fi}}{X}_i^p+\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{H}_l^{\mathrm{fl}}{X}_l^m+Z_n^f$

Be positioned at l (l ∈ 1 ..., L}) individual macrocell base stations overlay area m (m ∈ 1 ..., M}) and the signal vector that receives of individual macrocell user terminal can be expressed as:

$Y_l^m=H_l^{\mathrm{ml}}{X}_l^m+\underset{q\≠m}{\overset{M}{\underset{q=1}{\mathrm{\Σ}}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{j\≠l}{\overset{L}{\underset{j=1}{\mathrm{\Σ}}}}\underset{q=1}{\overset{M}{\mathrm{\Σ}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}\underset{f=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{mi}}{X}_i^f+Z_l^m$

In formula, represent and be under the jurisdiction of the Received signal strength that the n-th f of flying cellular basestation flies cellular user terminal, be f the desired signal flying cellular user terminal, represent the white Gaussian noise being under the jurisdiction of the n-th f of flying cellular basestation and flying cellular user terminal and receive, represent f the interference from same community flying cellular user terminal and receive, represent f the same layer interference flying honeycomb from other flying cellular user terminal and receive, represent the cross-layer interference that macrocell base stations flies cellular user terminal receive f; represent the Received signal strength being under the jurisdiction of m macrocell user terminal of l macrocell base stations, the desired signal of m macrocell user terminal, represent the white Gaussian noise that m macrocell user terminal receives, be the same area interference that m macrocell user terminal receives, the same layer interference from other macrocellulars that m macrocell user terminal receives, represent the cross-layer interference flying cellular basestation and m macrocell user terminal is received; X _n, X _i, X _land X _jrepresent n-th respectively, i (n, i ∈ 1 ..., N}) fly cellular basestation and l, j (l, j ∈ 1 ..., L}) and the transmission signal of individual macrocell base stations, further represent that xth to fly cellular basestation or the xth macrocell base stations T to y user terminal _x× 1 dimensional signal, T _xfor xth flies cellular basestation or an xth macrocell base stations antenna number; represent n-th respectively, i flies cellular basestation and l macrocell base stations to the individual channel condition information flying cellular user terminal of f; represent that l, j macrocell base stations and i-th fly the channel condition information of cellular basestation to m macrocell user terminal respectively.

Simultaneously, if sending set of signals s is the random vector signal meeting multiple Gaussian Profile, and targeted customer is respectively the n-th f flying cellular basestation flies cellular user terminal, and m macrocell user terminal of l macrocell base stations, then its transmitting terminal signal can be made to be respectively wherein for transmitting terminal pre-coding matrix.

Step 3: calculate the signal noise ratio of m macrocell user terminal received signal that the n-th f flying cellular basestation overlay area to fly cellular user terminal, a l macrocell base stations overlay area

${\mathrm{SNR}}_n^f=\frac{\mathrm{tr}\left(V_n^{\mathrm{fH}}{H}_n^{\mathrm{fnH}}{H}_n^{\mathrm{fn}}{V}_n^f\right)}{{\mathrm{\σ}}_n^{f2}}$ With ${\mathrm{SNR}}_l^m=\frac{\mathrm{tr}\left(V_l^{\mathrm{mH}}{H}_l^{\mathrm{mlH}}{H}_l^{\mathrm{ml}}{V}_l^m\right)}{{\mathrm{\σ}}_l^{m2}}$

In formula, (A) ^hthe conjugate transpose of representing matrix A, the mark of tr (A) representing matrix A, σ ²for user terminal noise variance.

Step 4: based on step 3 signal to noise ratio and each user terminal threshold value comparative result is adjudicated, if signal to noise ratio is greater than threshold value, implements interference and eliminates (step 5), if signal to noise ratio is less than threshold value, implement energy acquisition (step 10).

Step 5: user terminal obtains the hierarchical information of each unit in heterogeneous network and interference user channel condition information.Consider existing macrocellular network work characteristics, namely can avoid by methods such as such as frequency divisions with layer interference sections.For this reason, first same layer interference signal determined whether that macrocellular disturbs with layer, if macrocell user then adopts traditional means to eliminate with layer interference, if not then together continue process with other interference.

Step 6: calculate the two-layer heterogeneous network that interference occurs and whether meet interference alignment feasibility condition.Without loss of generality, macrocell user terminal can be made in two-layer heterogeneous network down link and flies cellular user terminal there is identical degree of freedom d.(when each user side has different d, also can obtain corresponding feasibility condition)

①T _L-M×d≥0,T _N-F×d≥0,T _M-d≥0,T _F-d≥0

② $\left\{\begin{array}{c}\underset{l:(l,n)\∈I}{\mathrm{\Σ}}(T_L-\mathrm{Md})\mathrm{Md}+\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}(F_d-d)d\≥2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\mathrm{Fd}\underset{k\∈K_n}{\mathrm{\Σ}}d\\ \max \{\underset{l\∈I_A}{\mathrm{\Σ}}{T}_L,\underset{i\∈I_B}{\mathrm{\Σ}}{T}_N,\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}{T}_F\}\≥\underset{l\∈I_A}{\mathrm{\Σ}}d+\underset{i\∈I_B}{\mathrm{\Σ}}d+\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}d\end{array}\right.$

③ $\left\{\begin{array}{c}\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}(T_M-d)d\≥\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\mathrm{Md}\underset{k\∈K_l}{\mathrm{\Σ}}d\\ \max \{\underset{i\∈I_E}{\mathrm{\Σ}}{T}_N,\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}{T}_M\}\≥\underset{i\∈I_E}{\mathrm{\Σ}}d+\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}d\end{array}\right.$

In formula, K _nbe the n-th random subset flying to fly in cellular basestation overlay area cellular user terminal set, K _lit is the random subset of macrocell user terminal set in l macrocell base stations.I represents all random subset producing the set of two different districts of interference.I _a, I _frepresent the random subset of macrocell base stations, I _b, I _c, I _erepresent the random subset flying cellular basestation, and formula 2. middle I _b, I _cwithout occuring simultaneously.

For fly cellular user terminal and macrocell user terminal should make its feasibility condition meet respectively formula 1., 2. with formula 1., 3., to ensure the transmitting of desired signal, rationally eliminate all kinds of interference.Now, then implementing interference elimination (step 7) as met above-mentioned feasibility condition, if do not meet, implementing energy acquisition (step 10).

Step 7: calculate that the f flying cellular basestation overlay area with n-th is individual flies transmitting terminal pre-coding matrix corresponding to cellular user terminal and the transmitting terminal pre-coding matrix corresponding with m macrocell user terminal of l macrocell base stations overlay area (in distributed iterative interference alignment techniques, the two initial value can be made to be respectively any T _f× d, T _m× d ties up unitary matrice).

Step 8: calculate n-th and to fly in cellular basestation overlay area f and fly cellular user terminal dl interference power approximation m macrocell user terminal down link interference power approximation in l macrocell base stations overlay area and respectively with threshold value compare.

$\mathrm{tr}\left(Q_n^f\right)=\mathrm{tr}\left(\underset{p\≠f}{\overset{F}{\underset{p=1}{\mathrm{\Σ}}}}{V}_n^{\mathrm{pH}}{H}_n^{\mathrm{fnH}}{H}_n^{\mathrm{fn}}{V}_n^p\right)+\mathrm{tr}\left(\underset{i\≠n}{\overset{N}{\underset{i=1}{\mathrm{\Σ}}}}\underset{p=1}{\overset{F}{\mathrm{\Σ}}}{V}_i^{\mathrm{pH}}{H}_i^{\mathrm{fiH}}{H}_i^{\mathrm{fi}}{V}_i^p\right)+\mathrm{tr}\left(\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{V}_l^{\mathrm{mH}}{H}_l^{\mathrm{flH}}{H}_l^{\mathrm{fl}}{V}_l^m\right)$

$\mathrm{tr}\left(Q_l^m\right)=\mathrm{tr}\left(\underset{q\≠m}{\overset{M}{\underset{q=1}{\mathrm{\Σ}}}}{V}_l^{\mathrm{qH}}{H}_l^{\mathrm{mlH}}{H}_l^{\mathrm{ml}}{V}_l^q\right)+\mathrm{tr}\left(\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\underset{f=1}{\overset{F}{\mathrm{\Σ}}}{V}_n^{\mathrm{fH}}{H}_n^{\mathrm{mnH}}{H}_n^{\mathrm{mn}}{V}_n^f\right)$

In formula expression n-th, individual f, p of flying cellular basestation overlay area of i fly transmitting terminal pre-coding matrix corresponding to cellular user terminal, represent the transmitting terminal pre-coding matrix that m, q macrocell user terminal of l macrocell base stations overlay area is corresponding.

Now, if dl interference power is less than threshold value, implements interference and eliminate (step 9), if dl interference power is greater than threshold value, implement energy acquisition (step 10).

Step 9: calculate n-th and to fly in cellular basestation overlay area f and fly cellular user terminal interference cancellation matrix m macrocell user end user terminal in l macrocell base stations overlay area the pre-coding matrix of each user and interference cancellation matrix is made to meet following concerns mandate:

Wherein, classical interference alignment techniques (be limited to the total number of users of target and be less than or equal to three) or distributed iterative interference alignment techniques (the total number of users no requirement (NR) of target) can be adopted solving in V, U process needed for interference alignment.Complete interference and eliminate rear administration step 11.

Step 10: calculate n-th and fly the individual energy acquisition information flying m macrocell user terminal in cellular user terminal, a l macrocell base stations overlay area of f in cellular basestation overlay area and respectively with threshold value compare.

$E_n^f=\mathrm{tr}(\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{V_i}^H{H}_i^{\mathrm{fiH}}{H}_i^{\mathrm{fi}}{V}_i+\underset{l=1}{\overset{L}{\mathrm{\Σ}}}{V_l}^H{H}_l^{\mathrm{flH}}{H}_l^{\mathrm{fl}}{V}_l+{\mathrm{\σ}}^2)$

$E_l^m=\mathrm{tr}(V_l^{\mathrm{mH}}{H}_l^{\mathrm{mlH}}{H}_l^{\mathrm{ml}}{V}_n^m+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{V_i}^H{H}_i^{\mathrm{miH}}{H}_i^{\mathrm{mi}}{V}_i+\underset{j\≠l}{\overset{L}{\underset{j=1}{\mathrm{\Σ}}}}{H}_j^{\mathrm{mj}}{H}_j^{\mathrm{mj}}+{\mathrm{\σ}}^2)$

If energy acquisition information is greater than threshold value, complete administration step 11 after energy acquisition, if energy acquisition information is less than threshold value, directly administration step 11.

Step 11: epicycle interference is eliminated and terminated with energy acquisition process, waits for that next cyclic process starts.

In addition to the implementation, the present invention can also have other execution modes, and all employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop in the protection range of application claims.

Claims (5)

1. the interference elimination of two-layer heterogeneous network and an energy acquisition compromise algorithm,

Described two-layer heterogeneous network down link comprises L macrocell base stations, a M macrocell user terminal, N number ofly flies cellular basestation, and F flies cellular user terminal, L>=1, M>=1, N>=1,1≤F≤4; Each macrocell base stations antenna number is T _l, respectively flying cell-site antenna number is T _n, respectively flying cellular user terminal antenna number is T _f, each macrocell user terminal antenna number is T _m, above-mentioned all number of antennas are all more than or equal to 1;

It is characterized in that, the method mainly comprises following steps:

Step one: initialization information is mutual, collects and obtains two-layer heterogeneous network base station ownership, antenna configuration, frequency, position, adjacent area parameter information; Collect the radio spatial channels state information between each layer user terminal and base station;

Step 2: set up two-layer isomery and fly cellular network downlink received signal model, in the downlink transmission of two-layer heterogeneous network, be positioned at the n-th (n ∈ { 1, N}) individual f (the f ∈ { 1 flying cellular access point overlay area,, F}) individual fly cellular user terminal place receive signal vector be expressed as:

$Y_n^f=H_n^{\mathrm{fn}}{X}_n^f+\underset{\underset{p\≠f}{p=1}}{\overset{F}{\mathrm{\Σ}}}{H}_n^{\mathrm{fn}}{X}_n^p+\underset{\underset{i\≠n}{i=1}}{\overset{N}{\mathrm{\Σ}}}\underset{p=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{fi}}{X}_i^p+\underset{l=1}{\overset{L}{\mathrm{\Σ}}}\underset{m=1}{\overset{M}{\mathrm{\Σ}}}{H}_l^{\mathrm{fl}}{X}_l^m+Z_n^f$

Be positioned at l (l ∈ 1 ..., L}) individual macrocell base stations overlay area m (m ∈ 1 ..., M}) and the signal vector that receives of individual macrocell user end is expressed as:

$Y_l^m=H_l^{\mathrm{ml}}{X}_l^m+\underset{q\≠m}{\overset{M}{\underset{q=1}{\mathrm{\Σ}}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{j\≠l}{\overset{L}{\underset{j=1}{\mathrm{\Σ}}}}\underset{q=1}{\overset{M}{\mathrm{\Σ}}}{H}_j^{\mathrm{mj}}{X}_j^q+\underset{i=1}{\overset{N}{\mathrm{\Σ}}}\underset{f=1}{\overset{F}{\mathrm{\Σ}}}{H}_i^{\mathrm{mi}}{X}_i^f+Z_l^m$

represent and be under the jurisdiction of the Received signal strength that the n-th f of flying cellular basestation flies cellular user terminal, be f the desired signal flying cellular user terminal, represent the white Gaussian noise being under the jurisdiction of the n-th f of flying cellular basestation and flying cellular user terminal and receive, represent f the interference from same community flying cellular user terminal and receive, represent f the same layer interference flying honeycomb from other flying cellular user terminal and receive, represent that macrocell base stations flies the cross-layer interference of cellular user terminal to f; represent the Received signal strength being under the jurisdiction of m macrocell user terminal of l macrocell base stations, represent the desired signal of m macrocell user terminal, represent the white Gaussian noise that m macrocell user terminal receives, be m macrocell user terminal receive from same area interference, the same layer interference from other macrocellulars that m macrocell user terminal receives, represent that flying cellular basestation disturbs the cross-layer of m macrocell user terminal; X _n, X _i, X _land X _jrepresent n-th respectively, i (n, i ∈ 1 ..., N}) fly cellular basestation and l, j (l, j ∈ 1 ..., L}) and the transmission signal of individual macrocell base stations, further represent that xth to fly cellular basestation or the xth macrocell base stations T to y user terminal _x× 1 dimensional signal, T _xfor xth flies cellular basestation or an xth macrocell base stations antenna number; represent n-th respectively, i flies cellular basestation and l macrocell base stations to the individual channel condition information flying cellular user terminal of f; represent that l, j macrocell base stations and i-th fly the channel condition information of cellular basestation to m macrocell user terminal respectively;

Step 3: calculate the signal to noise ratio of m macrocell user terminal received signal that the n-th f flying cellular basestation overlay area to fly cellular user terminal, a l macrocell base stations overlay area

Step 4: based on signal to noise ratio described in step 3 and each user terminal threshold value comparative result is adjudicated, if signal to noise ratio is greater than threshold value, interference described in administration step five is eliminated, if signal to noise ratio is less than threshold value, and energy acquisition described in administration step ten;

Step 5: user terminal obtains the hierarchical information of each unit in heterogeneous network and interference user channel condition information, the same layer interference in the final Received signal strength of macrocell user terminal adopts frequency division means to eliminate;

Step 6: calculate the two-layer heterogeneous network that interference occurs and whether meet interference alignment feasibility condition, to make in two-layer heterogeneous network down link macrocell user terminal and flies cellular user terminal and have identical degree of freedom d:

①T _L-M×d≥0，T _N-F×d≥0，T _M-d≥0，T _F-d≥0

② $\left\{\begin{array}{c}\underset{l:(l,n)\∈I}{\mathrm{\Σ}}(T_L-\mathrm{Md})\mathrm{Md}+\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}(T_F-d)d\≥2\×\underset{n:(n,l)\∈I}{\mathrm{\Σ}}\mathrm{Fd}\underset{k\∈K_n}{\mathrm{\Σ}}d\\ \max \{\underset{l\∈I_A}{\mathrm{\Σ}}{T}_L,\underset{i\∈I_B}{\mathrm{\Σ}}{T}_N,\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}{T}_F\}\≥\underset{l\∈I_A}{\mathrm{\Σ}}d+\underset{i\∈I_B}{\mathrm{\Σ}}d+\underset{n\∈I_C}{\mathrm{\Σ}}\underset{k\∈K_n}{\mathrm{\Σ}}d\end{array}\right.$

③ $\left\{\begin{array}{c}\underset{n:(n,l)\∈I}{\mathrm{\Σ}}(T_N-\mathrm{Fd})\mathrm{Fd}+\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}(T_M-d)d\≥\underset{l:(l,n)\∈I}{\mathrm{\Σ}}\mathrm{Md}\underset{k\∈K_l}{\mathrm{\Σ}}d\\ \max \{\underset{i\∈I_E}{\mathrm{\Σ}}{T}_N,\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}{T}_M\}\≥\underset{i\∈I_E}{\mathrm{\Σ}}d+\underset{l\∈I_F}{\mathrm{\Σ}}\underset{k\∈K_l}{\mathrm{\Σ}}d\end{array}\right.$

In formula, K _nbe the n-th random subset flying to fly in cellular basestation overlay area cellular user terminal set, K _lit is the random subset of macrocell user terminal set in l macrocell base stations; I represents all random subset producing the set of two different districts of interference, I _a, I _frepresent the random subset of macrocell base stations, I _b, I _c, I _erepresent the random subset flying cellular basestation, and formula 2. middle I _b, I _cwithout occuring simultaneously;

For fly cellular user terminal and macrocell user terminal should make its feasibility condition meet respectively formula 1., 2. with formula 1., 3., to ensure the transmitting of desired signal, all kinds of interference of reasonable elimination, now, as meet above-mentioned feasibility condition then administration step seven interference eliminate, if meet; the energy acquisition of administration step ten;

Step 7: calculate that the f flying cellular basestation overlay area with n-th is individual to fly transmitting terminal corresponding to cellular user terminal and disturb pre-coding matrix and the transmitting terminal corresponding with m macrocell user terminal of l macrocell base stations overlay area disturbs pre-coding matrix

Step 8: calculate n-th and to fly in cellular basestation overlay area f and fly the same layer of cellular user terminal, cross-layer dl interference power approximation m macrocell user terminal cross-layer dl interference power approximation in l macrocell base stations overlay area and respectively with threshold value compare; Wherein, the mark of tr (A) representing matrix A;

If dl interference power is less than threshold value, the interference of administration step nine is eliminated, if dl interference power is greater than threshold value, and the energy acquisition of administration step ten;

Step 9: calculate f and fly cellular user terminal and m macrocell user terminal interference cancellation matrix with complete interference and eliminate rear administration step 11;

Step 10: calculate n-th and fly the individual energy acquisition information flying m macrocell user terminal in cellular user terminal, a l macrocell base stations overlay area of f in cellular basestation overlay area and respectively with threshold value compare;

If energy acquisition information is greater than threshold value, complete administration step 11 after energy acquisition, if energy acquisition information is less than threshold value, directly administration step 11;

Step 11: epicycle interference is eliminated and terminated with energy acquisition process, waits for that next cyclic process starts.

2. the interference elimination of two-layer heterogeneous network as claimed in claim 1 and energy acquisition compromise algorithm, is characterized in that, the pre-coding matrix of step 7 in distributed iterative interference alignment techniques pre-coding matrix initial value is respectively any T _f× d, T _m× d ties up unitary matrice.

3. the interference elimination of two-layer heterogeneous network as claimed in claim 1 and energy acquisition compromise algorithm, is characterized in that, step 9 is specially calculating n-th and flies in cellular basestation overlay area f and fly cellular user terminal interference cancellation matrix m macrocell user end user terminal in l macrocell base stations overlay area the pre-coding matrix of each user and interference cancellation matrix is made to meet following concerns mandate:

$\begin{array}{c}{U_n}^{\mathrm{fH}}{H_l}^{\mathrm{fl}}{V}_l^m=0,\∀l=1...L,m=1...M\\ {U_n}^{\mathrm{fH}}{H_i}^{\mathrm{fi}}{V}_i^p=0,\∀i\≠n,p=1...F\\ {U_n}^{\mathrm{fH}}{H_n}^{\mathrm{fn}}{V_n}^p=0,\∀p\≠f\\ \mathrm{rank}\left({U_n}^{\mathrm{fH}}{H_n}^{\mathrm{fn}}{V_n}^f\right)=d\end{array}$ With $\begin{array}{c}{U_l}^{\mathrm{mH}}{H_n}^{\mathrm{mn}}{V_n}^f,\∀n=1...N,f=1...F\\ {U_l}^{\mathrm{mH}}{H_l}^{\mathrm{ml}}{V_l}^q=0,\∀q\≠m\\ \mathrm{rank}\left({U_l}^{\mathrm{mH}}{H_l}^{\mathrm{ml}}{V_l}^m\right)=d\end{array}$

4. the interference elimination of two-layer heterogeneous network as claimed in claim 1 and energy acquisition compromise algorithm, is characterized in that, when the total number of users of target is less than or equal to three, described step 9 adopts classical interference alignment techniques solving in V, U process needed for interference alignment.

5. the interference elimination of two-layer heterogeneous network as claimed in claim 1 and energy acquisition compromise algorithm, it is characterized in that, when the total number of users no requirement (NR) of target, described step 9 solve interference alignment needed for V, U process in adopt distributed iterative disturb alignment techniques.