CN103079211B - Heterogeneous network interference coordination method on basis of carrier aggregation - Google Patents

Abstract

The invention relates to a heterogeneous network interference coordination method on the basis of carrier aggregation. Due to consideration on that interference to Pico edge users is the most serious, and thus, the carrier aggregation characteristic is utilized to enable macro station not to send a control signaling on control channels of part of composition carriers and according to scheduled user information with the worst SINR (Signal Interference Noise Ratio) in the Pico edge users, transmission power of the macro station on data channels of the part of composition carriers is reduced, so that interference of the macro station to the control channels and the data channels of the Pico edge users is reduced to a great degree. Moreover, due to consideration on that reduction of the transmission power of the macro station on part of composition carriers possibly causes reduction of throughput of the macro station, by a cost function consisting of throughput loss of macro users and a throughput gain of the Pico edge users, the data channel transmission power of the macro station on the composition carriers which provide interference protection is determined, so that while the throughput of the Pico edge users is improved, the throughput loss of the macro station is reduced and the total throughput of a system is promoted.

Description

A kind of heterogeneous network disturbance coordination method based on carrier aggregation

Technical field

The invention belongs to the wireless access technology field in mobile communication, relate to the heterogeneous network dl interference coordination approach based on carrier aggregation technology in a kind of wireless communication system.

Background technology

For meeting growing covering and capacity requirement, LTE-A(Long Term Evolution-Advanced) introduce heterogeneous network, slightly stand by covering basic deploy Pico(in macro station), Femto(femto station), Relay(relay station) etc. low-power small station, further user and base station spacing, improve power system capacity and covering power, but meanwhile bring serious interference problem.In addition, in order to load balancing and be macro station load sharing further, its descending coverage is expanded by power bias in small station, but the expansion of this cell range has increased the weight of presence of intercell interference further, is positioned at the interference that cell range expansion area intra domain user is subject to especially serious.Carrier aggregation is another key technology of lte-a system, by continuous or discrete one-tenth sub-carrier multiple in aggregated spectrum for user provides more large bandwidth, and by avoiding presence of intercell interference for neighbor cell allocation heterogeneity carrier wave.Support that between the macro station-Pico of carrier aggregation, interference needs at first to solve.The existing heterogeneous network interference coordination schemes based on carrier aggregation or only consideration control channel interference or data channel interference, or some becomes the transmitted power of sub-carrier to obtain the raising of Pico edge user throughput by reducing macro station, and ignore transmitted power and reduce the macro station and overall system loss of throughput brought.Therefore the present invention proposes a kind of macro station-Pico heterogeneous network disturbance coordination method based on carrier aggregation newly, control channel and data channel interference can be avoided simultaneously, and ensure macro station throughput and overall system throughput while raising Pico edge user throughput.

Summary of the invention

Technical problem: the object of the invention is to propose a kind ofly to solve the control channel and data channel interference that small station edge customer is subject to, and while reducing the interference that small station edge customer is subject to, the loss of throughput of macro station can be reduced, reduce the heterogeneous network disturbance coordination method based on carrier aggregation that overall system performance declines.

Technical scheme: the heterogeneous network disturbance coordination method based on carrier aggregation of the present invention, comprises the steps:

Initialization base station and user: suppose each macro station or slightly stand to may be configured as sub-carrier set identical, be designated as K, each one-tenth sub-carrier has R Resource Block, each time frame comprises control channel and data channel, user's set in macro station overlay area is designated as U, and each user u has a target Signal to Interference plus Noise Ratio γ ^target, in order to ensure the service quality of user;

The first step: user determines Serving cell and user type: the Reference Signal Received Power that user receives from macro station is RSRP _u,M, be RSRP from the Reference Signal Received Power of slightly standing _{u, P}, select its Serving cell according to max (RSRP+bias) criterion, and determine that its user type is macro station user, slight central user of standing still stands edge customer slightly, by the most weak slight station Reference Signal Received Power RSRP _u,Pthe poorest slight station edge customer;

Second step: base station composition allocation of carriers mode is set: macro station side, the control channel of part basic ingredient carrier wave and data channel are all with full power transmissions, another part becomes the control channel of sub-carrier not send control signaling, data channel passes through dynamic-configuration low-power, for the user that slightly stands provides interference protection; Side, slight station, the composition carrier Control channel of interference-free protection is only when being disturbed the control channel protecting into sub-carrier and being not enough, for central user of slightly standing provides control channel, the data channel of the one-tenth sub-carrier of interference-free protection can be used for all users, the composition carrier Control channel being disturbed protection can be used for all users, and its data channel Priority Service is stood edge customer slightly;

3rd step: determine scheduled user: each time slot scheduling, each base station is selected to meet according to its service subscriber information and each Resource Block r across carrier wave proportional fair dispatching method being each sub-carrier k of one-tenth the user that composition allocation of carriers mode requires and is dispatched;

4th step: calculate the patient macro station maximum transmit power of station user slightly: the schedule information determined according to the 3rd step, if there is no Signal to Interference plus Noise Ratio cannot meet the edge customer of slightly standing that is scheduled of business demand, namely then enter the 7th step, otherwise control instruction to slight station feedback power, station is according to the information of the poorest slight station edge customer slightly, calculate this user the patient maximum interference I from around all macro stations ^max,

$I^{\max }=\frac{P_{u,P,k}}{{\mathrm{\γ}}^{t\arg \mathrm{et}}}-N_0---\left(1\right)$

Wherein, k is this user one-tenth sub-carrier used, P _{u, P, k}for power, the N from the carrier wave k slightly stood that receive ₀for noise power;

Recycle the interference I except other macro stations of slightly standing except the macro station of place produce _{m '}and channel gain G between this user and place macro station _u,M, calculate and the one-tenth sub-carrier CC of interference protection be provided _pon, the patient macro station maximum transmit power of this user

$P_{M,{\mathrm{CC}}_p}=\frac{I^{\max }-I_{M^{\′}}}{G_{u,M}}---\left(2\right);$

5th step: the systematic cost p after controlling according to following formula rated output, after ensureing that macro station reduces power, its loss of throughput can not be excessive, and the systematic cost function p after power controls is defined as macro station and reduces before and after power, station edge user throughput gain slightly with macro station loss of throughput difference, that is:

$p={\mathrm{Thr}}_{P\_\mathrm{edge}}^{\mathrm{Gain}}-{\mathrm{Thr}}_M^{\mathrm{Loss}}---\left(3\right);$

6th step: determine that macro station provides interference protection to become the transmitted power of sub-carrier: the systematic cost p after controlling according to the power calculated; systematic cost p>=0 after if power controls; showing that macro station reduces power is the loss that gain that Pico edge customer brings is greater than the user of macro station own, then will the 7th step is entered after providing interference protection to become the transmitted power of sub-carrier as macro station, otherwise, show that macro station loss of throughput is excessive, need to improve to ensure macro station throughput, at this moment get get back to the 5th step as the transmitted power providing interference protection to become sub-carrier, wherein dBm is power unit milliwatt;

7th step: terminate this flow process.

Beneficial effect: the present invention compared with prior art, has the following advantages:

By forbidding that macro station becomes on sub-carrier to send control signaling in a part, and the data channel transmitted power that this part becomes sub-carrier is reduced when the Pico edge customer service quality be scheduled for cannot be met, effectively can avoid the interference to Pico edge customer, and by becoming the edge customer of slightly standing of priority scheduling on sub-carrier to reduce the interference that station edge customer is slightly subject to further in this section.Thus improve Pico edge user throughput.Meanwhile, lose excessive cost by avoiding macro station user throughput and calculate, make macro station loss always be not more than the gain of Pico edge customer, effectively ensure that macro station throughput, and overall system throughput is improved.

Accompanying drawing explanation

Fig. 1 is the heterogeneous network disturbance coordination method entire flow based on carrier aggregation of the present invention.

Embodiment

Heterogeneous network disturbance coordination method based on carrier aggregation of the present invention, first, the user in system selects its Serving cell according to max (RSRP+bias) criterion, and determines its user type; Then for the sub-carrier method of salary distribution is arranged in base station; Then, in each time slot scheduling, according to the user's set determining to be scheduled across carrier wave ratio fair scheduling scheme; Whether next step exists SINR(Signal to Interference plus Noise Ratio according in scheduled user's set) excessively poor Pico(stands slightly) edge customer judges whether to carry out power control, and calculate the patient macro station maximum transmit power of the poorest user; Then the systematic cost after controlling as the transmitted power rated output that macro station provides interference protection to become sub-carrier by this transmitted power; If macro station loss of throughput is greater than the gain of Pico edge user throughput, then increase this transmitted power, recalculate the systematic cost after power control, until macro station loss of throughput is not more than the gain of Pico edge user throughput; Finally the power calculated being set to current time slots macro station provides interference protection to become the transmitted power of sub-carrier.Next time slot scheduling is entered after completing.

Provide a kind of embodiment for lte-a system, comprise the steps:

Initialization: suppose that each macro station or Pico(stand slightly) to may be configured as sub-carrier set identical, be designated as K, each one-tenth sub-carrier has R Resource Block, each time frame comprises control channel and data channel, user's set in macro station overlay area is designated as U, and each user u has a target Signal to Interference plus Noise Ratio γ ^target, in order to ensure the service quality of user;

The first step: user determines Serving cell and user type.The Reference Signal Received Power that user receives from macro station is RSRP _u,M, the Reference Signal Received Power from Pico is RSRP _{u, P}, select its Serving cell according to max (RSRP+bias) criterion, and determine that its user type is macro station user, Pico central user or Pico edge customer, by the most weak slight station Reference Signal Received Power RSRP _u,Pthe poorest slight station edge customer.

Second step: base station composition allocation of carriers mode is set.Macro station side, the control channel of a part of basic ingredient carrier wave and data channel are all with full power transmissions; Another part becomes the control channel of sub-carrier not send control signaling, and data channel passes through dynamic-configuration low-power, for Pico user provides interference protection.Pico side, the composition carrier Control channel of interference-free protection is only when being disturbed the control channel protecting into sub-carrier and being not enough, and for Pico central user provides control channel, the data channel of the one-tenth sub-carrier of interference-free protection can be used for all users; The composition carrier Control channel being disturbed protection can be used for all users, its data channel Priority Service Pico edge customer.

3rd step: determine scheduled user.Each time slot scheduling, each base station according to its service subscriber information with across carrier wave proportional fair dispatching method be each sub-carrier k(k ∈ K of one-tenth) each Resource Block r(r ∈ R) select to meet the user that composition allocation of carriers mode requires and dispatch.

4th step: calculate the patient macro station maximum transmit power of Pico user.According to schedule information, if there is no SINR(Signal to Interference plus Noise Ratio) the Pico edge customer that is scheduled of business demand cannot be met, namely then enter the 7th step, otherwise, control instruction to Pico feedback power, Pico according to the poorest Pico edge customer information, calculate this user the patient maximum interference I from around all macro stations ^max,

$I^{\max }=\frac{P_{u,P,k}}{{\mathrm{\γ}}^{t\arg \mathrm{et}}}-N_0---\left(1\right)$

Wherein, k is this user one-tenth sub-carrier used, P _{u, P, k}for power, the N from the carrier wave k slightly stood that receive ₀for noise power;

Recycle except the macro station of Pico place, the interference I that other macro stations produce _{m '}and channel gain G between this user and place macro station _u,M, calculate and the one-tenth sub-carrier CC of interference protection be provided _pon, the patient macro station maximum transmit power of this user

$P_{M,{\mathrm{CC}}_p}=\frac{I^{\max }-I_{M^{\′}}}{G_{u,M}}---\left(2\right)$

5th step: the systematic cost after controlling according to following formula rated output, after ensureing that macro station reduces power, its loss of throughput can not be excessive, and the systematic cost function p after power controls is defined as macro station and reduces before and after power, the gain of Pico edge user throughput with macro station loss of throughput difference, that is:

$p={\mathrm{Thr}}_{P\_\mathrm{edge}}^{\mathrm{Gain}}-{\mathrm{Thr}}_M^{\mathrm{Loss}}---\left(3\right)$

6th step: determine that macro station provides interference protection to become the transmitted power of sub-carrier.Systematic cost p after controlling according to the power that calculates, if p>=0, showing that macro station reduces power is the loss that gain that Pico edge customer brings is greater than the user of macro station own, then will the 7th step is entered after providing interference protection to become the transmitted power of sub-carrier as macro station.Otherwise, show that macro station loss of throughput is excessive, need to improve to ensure macro station throughput, at this moment get get back to the 5th step as the transmitted power providing interference protection to become sub-carrier, wherein dBm is power unit milliwatt, stops when namely the gain of Pico edge user throughput is greater than macro station loss of throughput, will now interference protection is provided to become the transmitted power of sub-carrier as macro station.

Claims (1)

1., based on a heterogeneous network disturbance coordination method for carrier aggregation, it is characterized in that, the method comprises the following steps:

Initialization base station and user: suppose each macro station or slightly stand to may be configured as sub-carrier set identical, be designated as K, each one-tenth sub-carrier has R Resource Block, each time frame comprises control channel and data channel, user's set in macro station overlay area is designated as U, and each user u has a target Signal to Interference plus Noise Ratio γ ^target, in order to ensure the service quality of user;

The first step: user determines Serving cell and user type: the Reference Signal Received Power that user receives from macro station is RSRP _u,M, be RSRP from the Reference Signal Received Power of slightly standing _u,P, select its Serving cell according to max (RSRP+bias) criterion, and determine that its user type is macro station user, slight central user of standing still stands edge customer slightly, by the most weak slight station Reference Signal Received Power RSRP _u,Pas the poorest slight station edge customer, the bias wherein in max (RSRP+bias) represents biased;

Second step: base station composition allocation of carriers mode is set: macro station side, the control channel of part basic ingredient carrier wave and data channel are all with full power transmissions, another part becomes the control channel of sub-carrier not send control signaling, data channel passes through dynamic-configuration low-power, for the user that slightly stands provides interference protection; Side, slight station, the composition carrier Control channel of interference-free protection is only when being disturbed the control channel protecting into sub-carrier and being not enough, for central user of slightly standing provides control channel, the data channel of the one-tenth sub-carrier of interference-free protection can be used for all users, the composition carrier Control channel being disturbed protection can be used for all users, and its data channel Priority Service is stood edge customer slightly;

3rd step: determine scheduled user: each time slot scheduling, each base station is selected to meet according to its service subscriber information and each Resource Block r across carrier wave proportional fair dispatching method being each sub-carrier k of one-tenth the user that composition allocation of carriers mode requires and is dispatched;

4th step: calculate the patient macro station maximum transmit power of station user slightly: the schedule information determined according to the 3rd step, if there is no Signal to Interference plus Noise Ratio cannot meet the edge customer of slightly standing that is scheduled of business demand, namely u _{p_edge}for edge customer of slightly standing, then enter the 7th step, otherwise control instruction to slight station feedback power, station is according to the information of the poorest slight station edge customer slightly, calculate this user the patient maximum interference I from around all macro stations ^max,

$I^{\max }=\frac{P_{u,P,k}}{{\mathrm{\γ}}^{t\arg \mathrm{et}}}-N_0---\left(1\right)$

Wherein, k is this user one-tenth sub-carrier used, P _{u, P, k}for power, the N from the carrier wave k slightly stood that receive ₀for noise power;

Recycle the interference I except other macro stations of slightly standing except the macro station of place produce _m'and channel gain G between this user and place macro station _u,M, calculate and the one-tenth sub-carrier CC of interference protection be provided _pon, the patient macro station maximum transmit power of this user

$P_{M,{\mathrm{CC}}_p}=\frac{I^{\max }-I_{M^{\′}}}{G_{u,M}}---\left(2\right);$

5th step: the systematic cost p after controlling according to following formula rated output, after ensureing that macro station reduces power, its loss of throughput can not be excessive, and the cost function p of system is defined as macro station and reduces before and after power, station edge user throughput gain slightly with macro station loss of throughput difference, that is:

$p={\mathrm{Thr}}_{P\_\mathrm{edge}}^{\mathrm{Gain}}-{\mathrm{Thr}}_M^{\mathrm{Loss}}---\left(3\right);$

6th step: determine that macro station provides interference protection to become the transmitted power of sub-carrier: the systematic cost p after controlling according to the power calculated; systematic cost p>=0 after if power controls; showing that macro station reduces power is the loss that gain that Pico edge customer brings is greater than the user of macro station own, then will the 7th step is entered after providing interference protection to become the transmitted power of sub-carrier as macro station, otherwise, show that macro station loss of throughput is excessive, need to improve to ensure macro station throughput, at this moment get get back to the 5th step as the transmitted power providing interference protection to become sub-carrier, wherein dBm is power unit milliwatt;

7th step: terminate this flow process.