CN101895940B - Method for distributing resources between main service cell and coordinate cells - Google Patents

Abstract

The present invention relates to a coordinated multi-point communication technology, and in particular to a method for coordinating resource allocation between a primary serving cell and a coordinated cell in a wireless cellular network, including that a user equipment receives reference signals sent by multiple cell base stations, selects The primary serving cell base station and the coordinated cell base station; the primary serving cell base station negotiates with the coordinated cell base station to select a transmission channel according to the service rate requirements of the user equipment and the channel parameters fed back; the primary serving cell base station and the coordinated Cell base stations negotiate and allocate cooperative power for coordinated multi-point transmission. Based on the existing cellular network architecture, the present invention directly negotiates with the base station of the main serving cell and the base station of the cooperative cell, optimizes the method of negotiation, and reduces the complexity of calculation and the interaction amount of signaling. Therefore, limited spectrum resources and power resources are fully utilized, interference is effectively avoided, and service quality at cell edges is improved.

Description

Method for resource allocation between main serving cell and cooperative cell

technical field

The invention relates to a technique for realizing coordinated multi-point communication, in particular to a method for resource allocation between a main serving cell and a coordinated cell in a wireless cellular network. the

Background technique

Most of the commercial wireless network operators now adopt the cellular network architecture. The cellular network architecture has the characteristics of high spectrum utilization, strong adaptability, and good scalability. However, due to the structural characteristics of the cellular network itself, there are disadvantages of low useful signal strength and high interference power at the edge of the cell. Therefore, how to improve the network service quality at the cell edge is a hot issue in the current wireless communication development. the

The Coordinated Multi-point (CoMP) technology is a key technical point proposed by the 3GPP organization in the LTE-A plan. The basic principle of coordinated multipoint communication technology is shown in Figure 1. In multiple cell base stations C1, C2, and C3, there are central user equipment UE3, UE4 and edge user equipment UE1, UE2, and the edge user equipment UE1 and UE2 have strong interference. , reduce the interference to the cell edge user equipment through joint scheduling, or further increase the receiving power of the cell edge user equipment through joint transmission, so as to improve the experience of the cell edge user equipment. Through the mutual cooperation between base stations, user equipment, base station and relay nodes, and user equipment and relay nodes, this technology solves the problems of co-channel interference between cells and the minimum antenna configuration of user terminal equipment, and can effectively improve the efficiency of the cell. The performance and sector throughput of the edge user equipment, while not bringing a large increase in complexity to the terminal equipment. the

However, although CoMP technology has broad application prospects, there are still many problems to be solved urgently in the technology itself. At present, the research on CoMP technology at home and abroad has just started, and a complete theoretical system has not been formed, and many key technical issues of CoMP have not been studied in depth. the

Due to the introduction of cooperative multipoint communication technology, the network topology of the traditional cellular communication system will be changed, and the original single centralized network structure will develop into a network structure combining centralized and distributed. The traditional coordinated multi-point communication is based on the central architecture, and a central node needs to collect relevant information of the main serving cell base station and the cooperative cell base station at the same time, such as channel conditions, minimum power vectors, etc., so the main serving cell base station and the cooperative cell base station The network transmission overhead caused by the base station transmitting these information to the central node is very heavy. the

In addition, after the central node in the traditional CoMP communication technology receives relevant information such as the channel conditions and the minimum power vector of the base station of the main serving cell and the base station of the cooperative cell, it selects a cooperative power each time and iteratively calculates the main serving cell The utility of the cell is improved and the utility of the cooperative cell is reduced, and the difference between the two is selected as the most appropriate cooperative power. Regardless of whether the compensation utility is greater than the sacrifice utility of the coordinated cell. the

Therefore, although the traditional collaborative communication solution based on a centralized network structure is feasible in theory, it is almost impossible to realize in practice due to its complexity. the

Contents of the invention

The present invention overcomes the above-mentioned shortcomings, and provides a practically feasible resource allocation method between the main serving cell and the cooperative cell with low calculation complexity, less signaling interaction, and a result close to optimal. the

The technical solution adopted by the present invention to solve the technical problem is: a method for resource allocation between the main serving cell and the cooperative cell, comprising the following steps,

The user equipment receives reference signals sent by multiple cell base stations, and selects the main serving cell base station and the coordinated cell base station;

The base station of the primary serving cell negotiates with the base station of the coordinated cell to select a transmission channel according to the service rate requirements of the user equipment and the channel parameters fed back;

Negotiating between the base station of the main serving cell and the base station of the cooperative cell, allocating cooperative power for coordinated multi-point transmission, further comprising,

The main serving cell base station allocates the minimum power for the selected transmission channel on the basis of meeting the minimum power requirement, and the cooperative cell base station obtains the cooperative power range that can be provided according to the remaining power;

The cooperative power of the cooperative cell base station is incremented by one power estimation sampling interval each time, and iteratively calculates the user utility and patience factor reduced by the cooperative transmission power provided by the main serving cell base station by the cooperative cell base station;

The base station of the main serving cell adopts the same sampling interval of the power estimation, and iteratively calculates the utility function and patience factor of the base station of the main serving cell;

After the base station of the main serving cell obtains the patience factors obtained by both parties after each sampling interval, it calculates the utility sharing ratio of the main serving cell and the cooperative cell, and calculates when the base station of the main serving cell obtains the maximum utility, the base station of the cooperative cell can obtain compensation utility;

After the coordinated cell base station receives the compensation utility, it judges that if the compensation utility is greater than the reduced user utility, it performs CoMP communication according to the current coordinated power.

The user equipment receives reference signals sent by multiple cell base stations, and the step of selecting the main serving cell base station and the coordinated cell base station may further include,

The user equipment acquires channel parameters and signal-to-interference-noise ratios between different cell base stations and the user equipment by receiving reference signals sent by multiple cell base stations, selects one of them as the main serving cell base station, and then uses the collected cell base stations The channel parameters and signal-to-interference-noise ratio are fed back to the main serving cell base station;

When the main serving cell base station judges that the user equipment is an edge user equipment according to the Signal to Interference plus Noise Ratio (SINR) fed back by the user equipment, select one of the remaining cell base stations as the coordinated cell base station. the

Based on the existing cellular network architecture, the present invention directly negotiates with the base station of the main serving cell and the base station of the cooperative cell, optimizes the method of negotiation, reduces the complexity of calculation and the amount of interaction of signaling, thereby making full use of limited spectrum resources and Power resources, effectively avoiding interference and improving service quality at the edge of the cell. In addition, by fully considering the compensation utility, when the compensation utility is greater than the utility sacrificed by the cooperative cell, the utility of both parties can be maximized, and the complexity of the negotiation algorithm is low, and the base station of the main serving cell and the base station of the cooperative cell need to interact There is less signaling data, which achieves a compromise between optimization and feasibility. the

Description of drawings

Fig. 1 is the schematic diagram of cooperative multi-point communication technology;

Fig. 2 is a flow chart of implementing coordinated multi-point communication by adopting the method of the present invention. the

Detailed ways

The content of the present invention will be described in detail below in conjunction with FIG. 1 . As shown in FIG. 2 , it is a flow chart of realizing coordinated multipoint communication by adopting the resource allocation method between the primary serving cell and the coordinated cell in the present invention. the

Step 1: User equipment UE1, UE2, UE3, and UE4 obtain channel parameters and signal-to-interference and noise ratios between different cell base stations and the user equipment by receiving reference signals sent by multiple cell base stations C1, C2, and C3 (Signal to Interference plus Noise Ratio, SINR, referred to as Signal to Interference and Noise Ratio), choose one of them as the main serving cell base station. Taking Figure 1 as an example, user equipments UE1 and UE4 select the cell where cell base station C2 is located as the main serving cell by comparing the obtained channel performances of base stations in each cell, and then collect the channel parameters sent by base stations in each cell and The SINR is fed back to the main serving cell base station C2. Similarly, the user equipment UE3 selects the cell where the cell base station C1 is located as the main serving cell, and feeds back the collected channel parameters and SINR of each cell base station to the main serving cell base station C1; the user equipment UE2 selects the cell where the cell base station C3 is located as the primary serving cell, and feeds back the collected channel parameters and SINR of each cell base station to the primary serving cell base station C3. the

Step 2: The main serving cell base station C2 judges whether the user equipment belongs to the edge user equipment or the central user equipment according to the SINR fed back by the user equipment. If it is an edge user equipment, choose to adopt the cooperative multipoint communication mode. In Fig. 1, user equipment UE4 is the central user equipment of the primary serving cell base station C2, user equipment UE3 is the central user equipment of the primary serving cell base station C1, user equipment UE1 is the edge user equipment of the primary serving cell base station C2, and user equipment UE2 is The edge user equipment of the main serving cell base station C3. The primary serving cell C2 selects one of the cells other than the primary serving cell as its cooperating cell according to the channel parameters and SINR detected by the edge user equipment UE1, that is, selects the cell base station C1 as the coordinating cell base station ; Similarly, the edge user equipment UE2 selects the cell base station C2 as the coordinated cell base station. the

Judging whether the user equipment belongs to the edge user equipment may, but not limited to, adopt the following method. the

Select a threshold value SINR_threshold, if the SINR of the user equipment is greater than SINR_threshold, it belongs to the central user equipment, otherwise it belongs to the edge user equipment. the

The method for selecting the coordinated cell may be, but not limited to, a cell with the best channel performance fed back by the user equipment among the cells other than the primary serving cell where it is located. the

Step 3: The base station of the main serving cell selects a suitable transmission channel for the user equipment according to the service rate requirement of the user equipment and the channel parameters fed back. the

The frequency band used by the central user equipment UE3 is independently determined by the main serving cell base station C2. The frequency band used by the edge user equipment UE1 is commonly used by edge user equipments of multiple coordinated cell sets. Therefore, for an edge user equipment UE1, assuming that the ID of its primary serving cell base station C2 is k, and the ID of the selected coordinated cell base station C1 is l, its primary serving cell base station C2 needs to negotiate with the coordinated cell base station C1 as a user equipment The channel frequency resource provided by UE1 selects a channel that is not occupied by base stations in each cell. The method for coordinating resource allocation between the primary serving cell and the coordinated cell will be described in detail below by taking the edge user equipment UE1 , the base station of the primary serving cell C2 , and the base station of the cooperative cell C1 as examples. the

Step 4: According to the channel parameters fed back by the user equipment UE1, the main serving cell base station C2 obtains the minimum power requirement of the user equipment UE1 for signal transmission, and then allocates the channel allocated for the user equipment UE1 after negotiation on the basis of meeting the minimum power requirement The minimum power is also allocated to each channel occupied by all other edge user equipments and central user equipments in the current main serving cell base station C2. At the same time, after the coordinated cell base station C1 allocates the minimum power to all edge user equipments and central user equipments using the cell as the main serving cell, it obtains the range of cooperative power that can be provided according to the remaining power. According to the same method, cell base station C2 also obtains the range of cooperative power it can provide. the

The method of calculating the minimum power condition can be calculated by the following formula

The method of allocating power to each channel may be, but not limited to, adopt the following water filling algorithm. the

A calculation method that provides a feasible range of cooperative power may be adopted, but not limited to, the minimum value is zero, and the maximum value is the difference between the total power and the allocated power. the

Step 5: After the coordinated cell base station C1 and the main serving cell base station C2 have negotiated the frequency resources provided to the user equipment UE1, within the feasible cooperative power range obtained in step 4, select an appropriate cooperative power estimation sampling interval (hereinafter referred to as sampling interval). The selection of the cooperation power starts from a minimum value, increments by one sampling interval each time, and then re-distributes power with the remaining power. Wherein, the minimum value of the sampling interval and the cooperative power may be preset, and the minimum value of the cooperative power may be set to 0. The power allocation adopts the same method as step 4. Then, corresponding to each increment of a sampling interval, iteratively calculate the user utility function (also called sacrifice utility) and patience factor that the cooperative cell base station C1 provides cooperative transmission power to the main serving cell base station C2. the

After the cooperative cell base station C1 iteratively calculates the entire feasible cooperative power range, it transmits the calculated patience factor and feasible cooperative power range to the main serving cell base station C2. the

user utility function It refers to the improvement or reduction of the user service quality caused by the increase or decrease of the transmission power of the user equipment, and the calculation method may be, but not limited to, the following formula.

The patience factor δ _slaving (t) of the cooperative cell refers to the degree to which the cooperative cell tolerates the sacrifice of utility. The calculation method can be, but not limited to, use the following formula to calculate.

Step 6: After receiving the feasible cooperative power range, the main serving cell base station C2 adopts the same power estimation sampling interval as the cooperative cell base station C1. Iteratively calculate the transmit power that the primary serving cell base station C2 can reduce for the edge user equipment UE1 due to the cooperative power provided by the coordinated cell base station C1. This part of the corresponding power is re-used in the main serving cell base station C2 for power allocation, which can bring about an improvement in the utility function of the user. Then, corresponding to each sampling interval, the user utility function and patience factor for each promotion are calculated. the

采用和步骤5相同的计算方法。  User's utility function

Use the same calculation method as step 5.

The patience factor δ _serving (t) of the main serving cell refers to the desire degree of the main serving cell for improving utility, and the calculation method may be but not limited to the following formula.

Step 7: After obtaining the patience factors obtained by both parties after each sampling interval, base station C2 of the primary serving cell calculates the utility sharing ratio of the primary serving cell and the cooperative cell according to the negotiated share. Calculate the maximum utility that the main serving cell base station C2 can share according to the sharing ratio and user utility, and then calculate the compensation utility that the cooperative cell base station C1 can get when the main serving cell base station C2 gets the maximum utility. The primary serving cell base station C2 sends the compensation utility information that can be obtained by the coordinated cell base station C1 to the coordinated cell base station C1. the

The calculation of the utility sharing ratio between the main serving cell base station C2 and the cooperative cell base station C1 can be, but not limited to, be calculated using the following formula. the

Then, according to the following formula, from the utility division after each sampling interval, the maximum value of utility allocated by the main serving cell base station C2 is obtained. the

The compensation utility of the cooperative cell base station C1 can be calculated by, but not limited to, the following formula

Step 8: After receiving the compensation utility, the base station C1 of the coordinated cell judges whether the compensation utility m is greater than the reduced user utility, that is, in step 5, when corresponding to the maximum value of the utility obtained by the main serving cell base station C2, the coordinated cell Cooperative power reduction of base stations for user utility. If it is greater than this value, the current CoMP request is successful, and the Cooperative Multipoint communication is performed according to the agreed power and frequency band; otherwise, the Coordinated Multipoint communication request is rejected. The coordinated cell base station C1 feeds back the request result to the main serving cell base station C2. the

Step 9: The main serving cell base station C2 receives the feedback request result. If the request is successful, the coordinated multi-point coordinated communication is provided for the user equipment on the negotiated frequency band and power resource with the base station C1 of the coordinated cell. If unsuccessful, keep the original transmission mode unchanged. the

The method for resource allocation between the main serving cell and the cooperative cell provided by the present invention has been introduced in detail above. In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The descriptions of the above embodiments are only used to help Understand the method of the present invention and its core idea; At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification It should not be construed as a limitation of the invention. the

Claims (2)

1. A method for resource allocation between a primary serving cell and a coordinated cell, characterized in that: comprising the following steps, The user equipment receives reference signals sent by multiple cell base stations, and selects the main serving cell base station and the coordinated cell base station; The base station of the main serving cell negotiates with the base station of the coordinated cell to select a transmission channel according to the service rate requirements of the user equipment and the channel parameters fed back; Negotiating between the primary serving cell base station and the coordinated cell base station, allocating cooperative power for coordinated multi-point transmission, further comprising: The main serving cell base station allocates minimum power to the selected transmission channel on the basis of meeting the minimum power requirement, and the cooperative cell base station obtains the cooperative power range that can be provided according to the remaining power; The cooperative power of the cooperative cell base station is incremented by one power estimation sampling interval each time, and iteratively calculates the user utility and patience factor reduced by the coordinated transmission power provided by the cooperative cell base station to the main serving cell base station; The primary serving cell base station uses the same power estimation sampling interval to iteratively calculate the utility function and patience factor of the primary serving cell base station; After the base station of the main serving cell obtains the patience factors obtained by both parties after each sampling interval, it calculates the utility sharing ratio of the main serving cell and the cooperative cell, and calculates when the base station of the main serving cell obtains the maximum utility, the base station of the cooperative cell can obtain Compensation effect; After receiving the compensation utility, the base station of the coordinated cell judges that if the compensation utility is greater than the reduced user utility, the coordinated multi-point communication is performed according to the current coordinated power; Wherein, the utility function represents the improvement or reduction of the user service quality caused by the increase or decrease of the transmission power of the user equipment, the patience factor of the cooperative cell represents the tolerance degree of the cooperative cell to the reduction of utility, and the main serving cell The patience factor of represents the desire degree of the main serving cell for utility improvement; the division ratio of the patience factor is used to represent the distribution of user utility, and further represents the distribution of power. 2. The method for resource allocation between the primary serving cell and the coordinated cell according to claim 1, wherein the user equipment receives reference signals sent by multiple cell base stations, and selects the primary serving cell base station and the coordinated cell base station The steps further include, The user equipment acquires channel parameters and signal-to-interference-noise ratios between different cell base stations and the user equipment by receiving reference signals sent by multiple cell base stations, selects one of them as the main serving cell base station, and then uses the collected cell base stations The channel parameters and signal-to-interference-noise ratio are fed back to the main serving cell base station; The main serving cell base station selects one of the remaining cell base stations as the coordinated cell base station when judging that the user equipment is an edge user equipment according to the SINR fed back by the user equipment.

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