CN105554805A - In-band full duplex D2D communication link interference elimination method used for cellular network - Google Patents

Abstract

The invention belongs to a full duplex D2D communication link interference elimination method, and particularly relates to an in-band full duplex D2D communication link interference elimination method used for a cellular network. The method includes: a base station, a cellular user, a couple of in-band full duplex D2D communication link users form a cellular network, and an in-band full duplex D2D communication link multiplexes cellular network downlink spectrum resources, and has a capability of simultaneous same-frequency signal sending and receiving; the method includes the cellular network transmitting base station BS of a point-to-point topological structure, the cellular network user USER1, the USER2 and USER3 which multiplex the cellular network downlink spectrum resources and adopt in-band full duplex D2D communication; and the in-band full duplex D2D communication users have the capability of receiving a signal while sending a signal, forward a monitored signal while sending a target signal, and allocate optimal transmitting power of the target signal and received signal, thereby improving communication quality of the in-band full duplex D2D communication link. The method utilizes the characteristic of simultaneous receiving and sending of in-band full duplex, and the overall performance of a cellular communication system is not influenced while D2D communication quality is improved.

Description

For full duplex D2D communication link interference elimination method in the band of cellular network

Technical field

The present invention relates to a kind of duplexing D2D communication link interference elimination method, particularly a kind of for full duplex D2D communication link interference elimination method in the band of cellular network.

Background technology

Along with emerging data service as video share, game on line, contiguous perception etc. continuous increase, the network performance mentioning cellular network becomes wireless communication field major issue urgently to be resolved hurrily.Device-to-Device (D2D) communication is considered to the effective communication technology of one promoting network performance in Next generation cellular net system.D2D communication is a kind of under the control of system, directly carried out the new technique communicated by reuse pattern resource between permission terminal, it can increase frequency spectrum efficiency of cellular communication system, reduces terminal transmit power, solves the problem of wireless communication system frequency spectrum resource scarcity to a certain extent.

D2D communication advantage is: the robustness etc. alleviating the burden of cellular network, reduce the battery power consumption of mobile terminal, increase bit rate, improve network infrastructure fault, can also support the novel service of Point-to-Point Data among a small circle.

One of subject matter of D2D communication is the interference problem that the resource of reuse pattern user is brought.

(1) D2D communicate multiplexing uplink resource time, in system by D2D Communication Jamming is base station, the adjustable D2D in base station communicate transmitted power and multiplexing resource control interference.

(2) D2D communicate multiplexed downlink resource time, by D2D Communication Jamming in system is the user of down link.When after D2D link establishment, the transmitted power that control D2D in base station transmits ensures the communication of system cell user.

In band, full duplex technology is specially adapted to the short haul connections such as D2D communication, and the availability of frequency spectrum can be improved 1 times by it, also can realize frequency spectrum more flexibly and use, be acknowledged as the important directions that 5G mobile communication system fully excavates radio spectrum resources.But when the down link of other user of the multiplexing Cellular Networks of full duplex D2D communication link in being with, although the community user of multiplexed resource and the interior full duplex D2D user of band separate on communication space, but due to the transmitting power that base station is larger, still interference can be caused to full duplex D2D user in band.

Summary of the invention

For the shortcoming of above-mentioned technology, the invention provides a kind of for full duplex D2D communication link interference elimination method in the band of cellular network, solve the transmitting power that base station is larger, the problem of interference is caused to full duplex D2D user in band.

For achieving the above object, of the present invention a kind of for full duplex D2D communication link interference elimination method in the band of cellular network, comprise base station, a phone user, in a pair band, full duplex D2D communication link user, uses BS respectively, USER1, USER2, USER3 represent, form the cellular network of full duplex D2D communication in an embedded, full duplex D2D communication link multiplexing Cellular Networks downlink tone spectrum resource in band, possess the ability of same frequency sending simultaneously and Received signal strength; Adopt user USER2 and USER3 that in the cellular transmission base station BS of point-to-point topological and the band of cellular network User USER1, multiplexing cellular network downlink tone spectrum resource, full duplex D2D communicates; In band, full duplex D2D communication user possesses the ability of Received signal strength while sending signal, by forwarding the signal listened to while sending echo signal, and distribute the transmitting power of echo signal and Received signal strength optimum, improve the communication quality of full duplex D2D communication link in band;

For full duplex D2D communication link interference elimination method in the band of cellular network, its method step is as follows:

A) in band, full duplex D2D communication user USER2 carries out D2D with user USER3 and communicates, and D2D communicates the frequency spectrum resource of down link that multiplexing base station BS communicates with USER1, and now base station BS just has interference to D2D communication link;

B) at the signal that receives of full duplex D2D communication link user USER2 reception antenna in band after self-interference elimination, the signal obtained will with send to the Signal averaging of D2D user USER3 after together sent by transmitting antenna, the composite signal obtained can be expressed as:

Wherein ω ₁, ω ₂represent power weight,

the phase delay of signal transacting,

Y ₂for the signal received with interior full duplex D2D communication link user USER2 reception antenna eliminates the Received signal strength obtained through self-interference,

S ₂it is the signal that USER2 sends to USER3;

In above formula wherein x ₂ ^*for the estimated value of the self-interference signal of user USER2; ${\tilde{y}}_2=\sqrt{P_1}{h}_{12}{s}_1+h_{22}{x}_2+h_{32}{x}_3+n_2,$

Wherein P ₁the transmitted power of base station,

S ₁the signal that base station sends to Cellular Networks receiving terminal USER1,

X ₃the signal that USER3 sends to USER2,

H ₁₂, h ₂₂, h ₃₂be the channel gain that the channel gain of USER1, the channel gain of USER2 to USER2 and USER3 to USER2 are arrived in base station respectively, user USER2 is n ₂it is white Gaussian noise;

Particularly, the signal that in band, full duplex D2D communication user USER2 reception antenna receives is eliminated through the positive self-interference of simulation, then eliminates through analog-to-digital conversion laggard line number word self-interference, obtains the interference signal y from base station BS ₂, according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂with weights power division, send to USER3 by radiating circuit;

C) signal that full duplex D2D communication link USER3 receives in band obtains after the elimination of self-interference signal: $y_3=h_{23}({\mathrm{\ω}}_1{e}^{j\mathrm{\φ}}\sqrt{P_1}{h}_{13}{s}_1+{\mathrm{\ω}}_2{s}_2+I_{22})+\sqrt{P_1}{h}_{13}{s}_1+I_{33}+n_3,$

Wherein I ₂₂, I ₃₃be the self-interference elimination error of USER2 and USER3 respectively, n3 is white Gaussian noise, and ω 1 and ω 2 is power weight, and h12, h23 and h13 are channel gain; Arriving of finally making base station disturb is offset, the final communication quality improved in D2D communication link.

Wherein full duplex D2D communication user power weights omega in band ₁and ω ₂solve and obtain: according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂, launched by radiating circuit;

Wherein channel gain h ₁₂, h ₂₃uSER2 can directly obtain, channel gain h ₁₃fed back by USER3.

The present invention has following beneficial effect: can make to be with interior full duplex D2D user USER3 to obtain maximized snr gain, ensure that full duplex D2D QoS of customer in band, promotes network performance.Compared with prior art, the method utilizes the characteristic that in band, full duplex is received and dispatched simultaneously, when making to be with interior full duplex D2D user multiplexing cellular network downlink tone spectrum resource, base station does not need the transmitted power controlling self, just can ensure that D2D communication quality does not send the impact of signal by cellular network base stations.Simultaneously owing to being with interior full duplex D2D user to receive and dispatch simultaneously, D2D can being increased in theory and to communicate the throughput of a times.In a word, the method, on the basis of overall performance not affecting cellular communication system, improves the communication quality in full duplex D2D communication link in band.

Accompanying drawing explanation

Fig. 1 is the Cellular Networks structural representation of full duplex D2D communication link in embedded.

Fig. 2 is the circuit design drawing of full duplex D2D communication link transmitting terminal in band.

Embodiment

Interference elimination method of the present invention comprises base station, a phone user, full duplex D2D communication link user in a pair band, use BS respectively, USER1, USER2, USER3 represent, form the cellular network of full duplex D2D communication in an embedded, full duplex D2D communication link multiplexing Cellular Networks downlink tone spectrum resource in band, possess the ability of same frequency sending simultaneously and Received signal strength; Adopt user USER2 and USER3 that in the cellular transmission base station BS of point-to-point topological and the band of cellular network User USER1, multiplexing cellular network downlink tone spectrum resource, full duplex D2D communicates; In band, full duplex D2D communication user possesses the ability of Received signal strength while sending signal, by forwarding the signal listened to while sending echo signal, and distribute the transmitting power of echo signal and Received signal strength optimum, improve the communication quality of full duplex D2D communication link in band.

Interference elimination method concrete steps are as follows:

A) in band, full duplex D2D communication user USER2 carries out D2D with user USER3 and communicates, and D2D communicates the frequency spectrum resource of down link that multiplexing base station BS communicates with USER1, and now base station BS just has interference to D2D communication link;

B) at the signal that receives of full duplex D2D communication link user USER2 reception antenna in band after self-interference elimination, the signal obtained will with send to the Signal averaging of D2D user USER3 after together sent by transmitting antenna, the composite signal obtained can be expressed as:

Wherein ω ₁, ω ₂represent power weight,

the phase delay of signal transacting,

Y ₂for the signal received with interior full duplex D2D communication link user USER2 reception antenna eliminates the Received signal strength obtained, s through self-interference ₂it is the signal that USER2 sends to USER3;

In above formula wherein x ₂ ^*for the estimated value of the self-interference signal of user USER2; ${\tilde{y}}_2=\sqrt{P_1}{h}_{12}{s}_1+h_{22}{x}_2+h_{32}{x}_3+n_2,$

Wherein P ₁the transmitted power of base station,

S ₁the signal that base station sends to Cellular Networks receiving terminal USER1,

X ₃the signal that USER3 sends to USER2,

H ₁₂, h ₂₂, h ₃₂be the channel gain that the channel gain of USER1, the channel gain of USER2 to USER2 and USER3 to USER2 are arrived in base station respectively, user USER2 is n ₂it is white Gaussian noise;

Particularly, the signal that in band, full duplex D2D communication user USER2 reception antenna receives is eliminated through the positive self-interference of simulation, then eliminates through analog-to-digital conversion laggard line number word self-interference, obtains the interference signal y from base station BS ₂, according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂with weights power division, send to USER3 by radiating circuit;

C) signal that full duplex D2D communication link USER3 receives in band obtains after the elimination of self-interference signal: $y_3=h_{23}({\mathrm{\ω}}_1{e}^{j\mathrm{\φ}}\sqrt{P_1}{h}_{13}{s}_1+{\mathrm{\ω}}_2{s}_2+I_{22})+\sqrt{P_1}{h}_{13}{s}_1+I_{33}+n_3,$ Wherein I ₂₂, I ₃₃be the self-interference elimination error of USER2 and USER3 respectively, n3 is white Gaussian noise; Arriving of finally making base station disturb is offset, the final communication quality improved in D2D communication link.

In band, full duplex D2D communication user transmits as x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂, in another band, the Received signal strength of full duplex D2D communication user after self-interference is eliminated is: wherein optimal power weights omega ₁, ω ₂solve as follows:

$\underset{{\mathrm{\ω}}_1,{\mathrm{\ω}}_2}{MAX}{\mathrm{SINR}}_{3,FD}=\frac{\left|h_{23}{|}^2\right|{\mathrm{\ω}}_2{|}^2}{P_1|h_{23}{h}_{12}{e}^{j\mathrm{\θ}}{\mathrm{\ω}}_1+h_{13}{|}^2+{\mathrm{\σ}}_n^2}$

Be limited by: $|{\mathrm{\ω}}_1{|}^2\left(P_1\right|h_2{|}^2+{\mathrm{\σ}}_I^2+{\mathrm{\σ}}_n^2)+|{\mathrm{\ω}}_2{|}^2\≤P_2,$

x ₂＝ω ₁e ^jθy ₂+ω ₂s ₂

Each parameter is defined as follows:

SINR _{3, FD}: the signal interference ratio of full duplex D2D communication link user USER3 Received signal strength in band;

P ₁: cellular transmission base station BS sends to the signal s of cellular network User USER1 ₁power;

P ₂: full duplex D2D communication link user maximum transmit power in band;

S ₁: cellular transmission base station BS sends to the signal of cellular network User USER1;

S ₂: the echo signal of full duplex D2D communication user USER2 to user USER3 in band;

X ₂: the signal of full duplex D2D communication user USER2 to user USER3 in band;

Y ₂: in band, full duplex D2D communication user USER2 is through eliminating the signal received of self-interference;

Y ₃: in band, full duplex D2D communication user USER3 is through eliminating the signal received of self-interference;

ω ₁, ω ₂: in band, full duplex D2D communication user USER2 sends the weights of the component in signal;

H ₁₃: full duplex D2D communication link user USER3 channel gain in cellular transmission base station BS to band;

H ₁₂: full duplex D2D communication link user USER2 channel gain in cellular transmission base station BS to band;

H ₂₃: full duplex D2D communication user USER2 to user USER3 channel gain in band;

H ₃₂: full duplex D2D communication user USER3 to user USER2 channel gain in band;

the mean square error that self-interference signal is eliminated;

the mean square error of Gaussian noise;

If then | ω ₂| ²value is maximum, makes SINR _{3, FD}there is maximum; And only have ω ₁phase potential energy affect P ₁| h ₂₃h ₁₂e ^{j θ}ω ₁+ h ₁₃| ²value, we consider P ₁| h ₂₃h ₁₂e ^{j θ}ω ₁+ h ₁₃| ²>=P ₁| h ₂₃h ₁₂e ^{j θ}ω ₁-h ₁₃| ², then h ₂₃h ₁₂e ^{j θ}ω ₁>=-λ h ₁₃, λ > 0, optimum then demand fulfillment:

$\frac{{\mathrm{\ω}}_1^{*}}{\left|{\mathrm{\ω}}_1^{*}\right|}=\frac{h_{13}\left|h_{23}\right|\left|h_{12}\right|e^{-j\mathrm{\θ}}}{\left|h_{13}\right|h_{23}{h}_{12}}$

Then:

$|{\mathrm{\ω}}_1{|}^2\left(P_1\right|h_{12}{|}^2+{\mathrm{\σ}}_I^2+{\mathrm{\σ}}_n^2)+|{\mathrm{\ω}}_2{|}^2\≤P_2$

Solve to obtain ω ₁optimal value:

$\begin{array}{c}\left|{\mathrm{\ω}}_1^{*}\right|=\frac{P_2|h_{23}{|}^2+P_1|h_{23}{|}^2+\sqrt{{\left(P_2\right|h_{23}{|}^2+P_1\left|h_{23}{|}^2\right)}^2-\frac{4P_2\left|h_{23}{|}^2{P_1}^2\right|h_{23}{|}^2\left|h_{12}{|}^2\right|h_{13}{|}^2}{P_1\left|h_{23}{|}^2\right|h_{12}{|}^2}}}{2P_1\left|h_{23}\right|\left|h_{12}\right|\left|h_{13}\right|}\\ =\frac{\min \left(P_2\right|h_{23}{|}^2,P_1\left|h_{13}{|}^2\right)}{2P_1\left|h_{23}\right|\left|h_{12}\right|\left|h_{13}\right|}\end{array}$

$\left|{\mathrm{\ω}}_2^{*}\right|=\sqrt{P_2-|{\mathrm{\ω}}_1^{*}{|}^2\left(P_1\right|h_{12}{|}^2+{\mathrm{\σ}}_I^2+{\mathrm{\σ}}_n^2)}$

${\mathrm{SINR}}_{3,FD}\≈\frac{P_1{P}_2\left|h_{13}{|}^2\right|h_{23}{|}^2-\min \left(P_1\right|h_{13}|,P_2|h_{23}\left|\right)}{{\left(\min \right(P_1\left|h_{13}\right|,P_2\left|h_{23}\right|)-P_1|h_{13}{|}^2)}^2+(\frac{\min \left(P_1\right|h_{13}|,P_2|h_{23}\left|\right)}{P_1|h_{12}{|}^2}+P_1|h_{13}{|}^2){\mathrm{\σ}}_n^2}$

Full duplex D2D communication user transmitting power weight optimal value ω in band is calculated by above-mentioned ₁and ω ₂; In band full duplex D2D communication user through self-interference eliminate the Received signal strength that obtains will with send to the echo signal of user according to formula together sent by transmitting antenna after superposition, then in another band full duplex D2D communications-user-receipt to signal be the superposition of echo signal, known self-interference signal and base station interference signal, through actively the elimination of simulation self-interference signal and digital adaptation are eliminated, interference signal is offset, the final communication quality improved in band in full duplex D2D communication link.

Below in conjunction with Figure of description an example of the present invention made and further describing:

As shown in Figure 1, for full duplex D2D communication link interference elimination method in the band of cellular network, comprise base station, a phone user, in a pair band, full duplex D2D communication user, uses BS respectively, and USER1, USER2, USER3 represent.Suppose a cell scenario, channel is rayleigh fading channel, and in band, the transmitting power of full duplex D2D communication link is less relative to the transmitting power of base station, does not affect the communication of phone user USER1.The identical resource in different communication region is given in base station, and the down link that base station BS communicates with USER1 just has interference to being with interior full duplex D2D communication link.

The elimination base station interference elimination method step based on full duplex of D2D communication is as follows:

A) in band, full duplex D2D communication link user USER2 carries out D2D with user USER3 and communicates, and D2D communicates the frequency spectrum resource of down link that multiplexing base station BS communicates with USER1, and now base station BS just has interference to D2D communication link;

B) at the signal that receives of full duplex D2D communication link user USER2 reception antenna in band after self-interference elimination, the signal obtained will with send to the Signal averaging of user USER3 after together sent by transmitting antenna, the composite signal obtained can be expressed as: wherein ω ₁, ω ₂represent power weight, the phase delay of signal transacting, y ₂for the signal received with interior full duplex D2D communication link user USER2 reception antenna eliminates the Received signal strength obtained, s through self-interference ₂it is the signal that USER2 sends to USER3; In above formula wherein x ₂ ^*for the estimated value of the self-interference signal of user USER2; wherein P ₁the transmitted power of base station, s ₁the signal that base station sends to Cellular Networks receiving terminal USER1, x ₃the signal that USER3 sends to USER2, h ₁₂, h ₂₂, h ₃₂be the channel gain that the channel gain of USER1, the channel gain of USER2 to USER2 and USER3 to USER2 are arrived in base station respectively, user USER2 is n ₂it is white Gaussian noise.Particularly, the signal that in band, full duplex D2D communication user USER2 reception antenna receives is eliminated through the positive self-interference of simulation, then eliminates through analog-to-digital conversion laggard line number word self-interference, obtains the interference signal y from base station BS ₂, according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂with weights power division, send to USER3 by radiating circuit.

C) signal that full duplex D2D communication link USER3 receives in band obtains after the elimination of self-interference signal: $y_3=h_{23}({\mathrm{\ω}}_1{e}^{j\mathrm{\φ}}\sqrt{P_1}{h}_{13}{s}_1+{\mathrm{\ω}}_2{s}_2+I_{22})+\sqrt{P_1}{h}_{13}{s}_1+I_{33}+n_3,$ Wherein I ₂₂, I ₃₃the self-interference elimination error of USER2 and USER3 respectively, n ₃for white Gaussian noise.Arriving of finally making base station disturb is offset, the final communication quality improved in the interior full duplex D2D communication link of band.

According to above-mentioned for full duplex D2D communication link interference elimination method in the band of cellular network, wherein full duplex D2D communication user optimal transmit power weights omega in band ₁and ω ₂solve and obtain: according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂, launched by radiating circuit;

According to above-mentioned for full duplex D2D communication link interference elimination method, wherein channel gain h in the band of cellular network ₁₂, h ₂₃uSER2 can directly obtain, h ₁₃fed back by USER3.

Claims (3)

1. one kind for full duplex D2D communication link interference elimination method in the band of cellular network, it is characterized in that: interference elimination method comprises base station, a phone user, full duplex D2D communication link user in a pair band, use BS respectively, USER1, USER2, USER3 represent, form the cellular network of full duplex D2D communication in an embedded, full duplex D2D communication link multiplexing Cellular Networks downlink tone spectrum resource in band, possesses the ability of same frequency sending simultaneously and Received signal strength; Adopt user USER2 and USER3 that in the cellular transmission base station BS of point-to-point topological and the band of cellular network User USER1, multiplexing cellular network downlink tone spectrum resource, full duplex D2D communicates; In band, full duplex D2D communication user possesses the ability of Received signal strength while sending signal, by forwarding the signal listened to while sending echo signal, and distribute the transmitting power of echo signal and Received signal strength optimum, improve the communication quality of full duplex D2D communication link in band.

2. according to claim 1 a kind of for full duplex D2D communication link interference elimination method in the band of cellular network, it is characterized in that: interference elimination method concrete steps are as follows:

A) in band, full duplex D2D communication user USER2 carries out D2D with user USER3 and communicates, and D2D communicates the frequency spectrum resource of down link that multiplexing base station BS communicates with USER1, and now base station BS just has interference to D2D communication link;

B) at the signal that receives of full duplex D2D communication link user USER2 reception antenna in band after self-interference elimination, the signal obtained will with send to the Signal averaging of D2D user USER3 after together sent by transmitting antenna, the composite signal obtained can be expressed as:

Wherein ω ₁, ω ₂represent power weight,

the phase delay of signal transacting,

Y ₂for the signal received with interior full duplex D2D communication link user USER2 reception antenna eliminates the Received signal strength obtained, s through self-interference ₂it is the signal that USER2 sends to USER3;

In above formula wherein x ₂ ^*for the estimated value of the self-interference signal of user USER2; ${\tilde{y}}_2=\sqrt{P_1}{h}_{12}{s}_1+h_{22}{x}_2+h_{32}{x}_3+n_2,$

Wherein P ₁the transmitted power of base station,

S ₁the signal that base station sends to Cellular Networks receiving terminal USER1,

X ₃the signal that USER3 sends to USER2,

H ₁₂, h ₂₂, h ₃₂be the channel gain that the channel gain of USER1, the channel gain of USER2 to USER2 and USER3 to USER2 are arrived in base station respectively, user USER2 is n ₂it is white Gaussian noise;

Particularly, the signal that in band, full duplex D2D communication user USER2 reception antenna receives is eliminated through the positive self-interference of simulation, then eliminates through analog-to-digital conversion laggard line number word self-interference, obtains the interference signal y from base station BS ₂, according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂with weights power division, send to USER3 by radiating circuit;

C) signal that full duplex D2D communication link USER3 receives in band obtains after the elimination of self-interference signal: $y_3=h_{23}({\mathrm{\ω}}_1{e}^{j\mathrm{\φ}}\sqrt{P_1}{h}_{13}{s}_1+{\mathrm{\ω}}_2{s}_2+I_{22})+\sqrt{P_1}{h}_{13}{s}_1+I_{33}+n_3,$ Wherein I ₂₂, I ₃₃be the self-interference elimination error of USER2 and USER3 respectively, n3 is white Gaussian noise; Arriving of finally making base station disturb is offset, the final communication quality improved in D2D communication link.

3. according to claim 2 a kind of for full duplex D2D communication link interference elimination method in the band of cellular network, it is characterized in that: described power weights omega ₁and ω ₂solve and obtain: according to formula x ₂=ω ₁e ^{j θ}y ₂+ ω ₂s ₂, launched by radiating circuit; Described channel gain h ₁₂, h ₂₃uSER2 can directly obtain, described channel gain h ₁₃fed back by USER3.