CN103379638A - Method for distributing resources - Google Patents

Abstract

The present invention provides a resource allocation method with better performance and lower complexity and the corresponding base station and CU. Wherein, the method includes: the base station allocates the resources of a single cell to the subchannels in its own available subchannel set, and after receiving the interference information reported by the user, respectively selects the S subchannels that suffer the most interference from them, and allocates the S subchannels The interference information corresponding to the channel is sent to the central controller (CU); the CU generates an interference list according to the interference information reported by each base station, and determines it in the interference list according to the serving base station ID and the interference base station ID corresponding to each sub-channel recorded in the interference list Record the base stations that perform cooperative transmission on each subchannel, and notify the base stations that perform cooperative transmission; each base station performs cooperative transmission according to the CU's instructions, and deletes these subchannels that require cooperative transmission from its own subchannel set to update Its own set of available subchannels.

Description

A Resource Allocation Method

technical field

The invention relates to wireless communication technology, in particular to a resource allocation method applied to a multi-cell Orthogonal Frequency Division Multiplexing (OFDMA) environment.

Background technique

Currently, resource allocation methods in a multi-cell OFDMA environment mainly include a central resource allocation method and a distributed resource allocation method.

Among them, the centralized resource allocation method requires a central controller (CU) to complete the process of resource allocation. When performing resource allocation, the CU needs to know the channel information of all users on all channels in the entire multi-cell OFDMA network, and then perform unified resource allocation in the entire network according to the channel information of all users on all channels. Obviously, this centralized resource allocation method can achieve good resource utilization and can also realize cooperative transmission between base stations. However, due to bandwidth limitations, feedback delays, and user equipment limitations, in actual applications, CU It is difficult to obtain channel information of all users in the entire network on all channels, which makes the central resource allocation method difficult to use in practical applications. In addition, the above-mentioned centralized resource allocation method has high requirements on the processing capability of the CU, and the larger the network, the higher the complexity of the CU.

In the distributed resource allocation method, the CU does not need to know the channel information of all users in the entire network on all channels, so the distributed resource allocation method is easier to implement than the central resource allocation method, and is more suitable for practical application. Moreover, the distributed resource allocation method can effectively solve the problem of high CU complexity in the central resource allocation method. However, the existing distributed resource allocation methods are either static algorithms with low complexity but poor performance; or quasi-static or dynamic algorithms with good performance but high computational complexity.

At present, the existing commonly used static distributed resource allocation methods mainly include frequency reuse factor 3 (Reuse-3) method and soft frequency reuse method (FFR, fractional frequency reuse). Among them, the main idea of frequency reuse factor 3 is to divide all sub-channels into 3 parts, each cell can get 1/3 of the channel, and the 6 cells surrounding a cell all use sub-channels different from it. In this way, any three adjacent cells use mutually orthogonal sub-channels, and each accounts for 1/3 of the total channel. This method can simply and effectively solve the problem of inter-cell interference, but its disadvantages are also obvious. Compared with the method with a frequency reuse factor of 1, its spectrum utilization rate is only 1/3. The soft frequency reuse method is to divide all users into cell center users and cell edge users according to the distance between the users and the cell base station. All sub-channels are divided into two parts, each occupying 1/2, and all users in the center of the cell share 1/2 of the total channel; the edge users of each cell use 1/3 of the other 1/2 sub-channels, That is, 1/6 of all sub-channels, similar to the method of frequency reuse factor 3, the edge users of any three adjacent cells use different sub-channels. This method is more flexible than the method with a frequency reuse factor of 3, and the frequency reuse factor is a fraction greater than 1 and less than 2, so it is called a soft frequency reuse method.

The existing quasi-static or dynamic distributed resource allocation methods are basically realized by using game theory algorithms. The following briefly describes the resource allocation process of a typical game algorithm based on virtual referees:

The first step, initialization: set the transmission rate Ri of each user, and assume that the transmission channel set Si of each user includes all sub-channels;

进行博弈，即在满足传输速率的基础上，减少用户所在信道的发射功率（通过设定发射功率的值仅取0或1达到信道分配目的）；In the second step, let each user follow the

Play a game, that is, reduce the transmission power of the channel where the user is located on the basis of satisfying the transmission rate (by setting the value of the transmission power to only take 0 or 1 to achieve the purpose of channel allocation);

The third step is to check whether the Nash Equilibrium Point (NEP) has been reached, if yes, then go to the fourth step, otherwise, go back to the second step;

进行博弈，即功率达到最大设定值的情况下，使其传输速率最大。（通过设定发射功率的值仅取0或1达到信道分配目的），如果博弈收敛，跳至第五步，否则跳至第二步；Step 4: For users who still cannot reach the set transmission rate Ri under the maximum set power, make them follow the

The game is played, that is, when the power reaches the maximum set value, the transmission rate is maximized. (The purpose of channel allocation is achieved by setting the value of the transmit power to only take 0 or 1), if the game converges, skip to the fifth step, otherwise skip to the second step;

Step five, follow $(l,j)=\arg \underset{l,j}{\min }\frac{P_j^l{G}_{\mathrm{jj}}^l}{{{\mathrm{\Σ}}_{k\≠j}P}_k^l{G}_{\mathrm{kj}}^l+N_0}$ Eliminate some of the channels allocated to users, and skip to the second step.

The performance of the above resource allocation method is very good, but the complexity is very high, about O(LMNlogN).

Contents of the invention

The embodiment of the present invention proposes a resource allocation method, which is applicable to a multi-cell OFDMA environment, can realize resource allocation in a multi-cell OFDMA environment, and has better performance and lower complexity.

The resource allocation method proposed by the embodiment of the present invention includes: each base station allocates resources for a single cell to the sub-channels in its available sub-channel set; each user reports to its serving base station the channel with the strongest interference. The interference information corresponding to the sub-channel; wherein, the interference information includes: the sub-channel identification ID, the interfering base station ID, and the interference value received; after each base station receives the interference information reported by the user, it selects the most interfered S sub-channels, and send the interference information corresponding to the S sub-channels to the CU; wherein, the S is a natural number; the CU generates an interference list according to the interference information reported by each base station, and records the serving base stations of the T sub-channels that suffer the most interference ID and its corresponding interference information; wherein, the T is a natural number; the CU determines to perform cooperative transmission on each sub-channel recorded in the interference list according to the serving base station ID and the interfering base station ID corresponding to each sub-channel recorded in the interference list base station, and notify the base station for cooperative transmission; and each base station performs cooperative transmission on the sub-channels that need cooperative transmission according to the instruction of CU, and deletes these sub-channels that need cooperative transmission from its own sub-channel set to update its own set of available subchannels.

Another resource allocation method proposed by the embodiment of the present invention includes: each base station performs resource allocation for a single cell to the subchannels in its own available subchannel set; each user reports to its own serving base station The signal-to-interference and noise ratio and the reference signal received power from each base station; each base station selects S subchannels with the smallest SINR from its own subchannels, and divides the subchannel IDs corresponding to these S subchannels by The ID of the base station corresponding to the strongest reference signal received power outside itself and the reference signal received power of the base station are sent to the central controller CU as the subchannel ID, the interfering base station ID and the interference value in the interference information; wherein, the S is a natural number ; The CU generates an interference list according to the interference information reported by each base station, and records the IDs of the serving base stations and the corresponding interference information of the T sub-channels most interfered with; wherein, the T is a natural number; the CU records each sub-channel according to the interference list The ID of the serving base station and the ID of the interfering base station corresponding to the channel determine the base station for cooperative transmission on each sub-channel recorded in the interference list, and notify the base station for cooperative transmission; Cooperative transmission is performed on sub-channels, and these sub-channels requiring cooperative transmission are deleted from its own sub-channel set to update its own available sub-channel set.

Wherein, each base station performs single-cell resource allocation on the sub-channels in its own available sub-channel set, including: each base station uses an adaptive single-cell resource allocation method to perform single-cell resource allocation. Alternatively, each base station uses a greedy algorithm to allocate resources for a single cell.

The above S and T are a predetermined fixed value; or a value dynamically determined according to the total number of interfered sub-channels reported by the user. For example, the above S and T are set as a certain proportion of the total number of interfered sub-channels reported by the user.

The above method further includes: if two adjacent base stations report the interference information of the same sub-channel to the CU at the same time and this sub-channel belongs to T sub-channels with the highest interference, the CU selects the interference information with stronger interference and records it in the interference list middle.

According to the serving base station ID and interfering base station ID corresponding to each subchannel recorded in the interference list, the CU determines the base station for cooperative transmission on each subchannel recorded in the interference list includes: for a subchannel n recorded in the interference list, assuming the serving The base station is base station i, and its interfering base station is base station j, then it is determined that the base stations performing cooperative transmission on sub-channel n are base station i and base station j; and base station i and base station j serve together and use sub-channel n in the cell corresponding to base station i that user.

The above method further includes: in the next time slot, returning to the step of each base station performing resource allocation of a single cell to the subchannels in its own available subchannel set and continuing to execute.

The base stations proposed in the embodiments of the present invention include:

a single-cell resource allocation unit, configured to perform single-cell resource allocation on subchannels in its own set of available subchannels;

The interference information receiving unit is used to receive the interference information corresponding to the subchannel with the strongest interference reported by the user it serves; wherein, the interference information includes: subchannel ID, interfering base station ID, and interference value received ;

The interference information reporting unit is used to select the S subchannels that suffer the most interference from the interference information reported by the users served by itself, and send the interference information corresponding to the S subchannels to the central controller CU; wherein, the S is a natural number ;as well as

The cooperative transmission unit is configured to perform cooperative transmission on the subchannels that require cooperative transmission according to the instructions of the CU, and delete these subchannels that require cooperative transmission from its own subchannel set to update its own available subchannel set .

The base station proposed in another embodiment of the present invention includes:

a single-cell resource allocation unit, configured to perform single-cell resource allocation on subchannels in its own set of available subchannels;

The interference information receiving unit is used to receive the signal-to-interference-noise ratio on all sub-channels reported by the user served by itself and the reference signal received power from each base station;

The interference information reporting unit is used to select S subchannels with the smallest signal-to-interference-noise ratio from its own subchannels, and report the subchannel IDs corresponding to these S subchannels and the base station corresponding to the strongest reference signal received power other than itself The ID and the reference signal received power of the base station are sent to the central controller CU as the subchannel ID, the interfering base station ID and the interference value in the interference information; wherein, the S is a natural number; and

The cooperative transmission unit is configured to perform cooperative transmission on the subchannels that require cooperative transmission according to the instructions of the CU, and delete these subchannels that require cooperative transmission from its own subchannel set to update its own available subchannel set .

The CU proposed in the embodiment of the present invention includes:

An interference list generating unit, configured to generate an interference list according to the interference information reported by each base station, and record the serving base station IDs and corresponding interference information of T subchannels most interfered with; wherein T is also a natural number; and

The cooperative transmission determining unit is configured to determine the base station for cooperative transmission on each subchannel recorded in the interference list according to the serving base station ID and the interfering base station ID corresponding to each subchannel recorded in the interference list, and notify the base station for cooperative transmission.

The resource allocation method provided by the embodiment of the present invention is a distributed method. The CU does not need to know the channel information of all users in the entire multi-cell OFDMA network on all channels. Therefore, compared with the existing centralized resource allocation method, It is more suitable for practical application; in addition, it also greatly reduces the complexity of CU. Secondly, in the resource allocation method proposed by the embodiment of the present invention, the CU can generate an interference list according to the interference information reported by each base station, and further determine base stations for cooperative transmission on some sub-channels with strong interference according to the interference list. Since the existing distributed resource allocation method cannot realize cooperative transmission between base stations, the method proposed in the embodiment of the present invention can improve the whole network while eliminating the strongest interference compared with the existing distributed resource allocation method. The throughput of the network.

Description of drawings

FIG. 1 is a flowchart of a resource allocation method according to an embodiment of the present invention;

FIG. 2 is a flowchart of each base station using a greedy algorithm to allocate resources in a single cell in the method described in the embodiment of the present invention;

FIG. 3 is a schematic diagram of an internal structure of a base station according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of an internal structure of a CU according to an embodiment of the present invention; and

Figure 5 shows the average cell throughput under different cell loads when different resource allocation methods are used.

Detailed ways

The resource allocation method proposed in the embodiment of the present invention will be described in detail below through specific examples.

The resource allocation method described in this embodiment is applicable to a multi-cell OFDMA network. Assume that the multi-cell OFDMA network applied in the embodiment of the present invention includes L cells, and each cell has K _l users, where l=1, 2, . . . , L. Therefore, the total number of users in the entire multi-cell OFDMA network is

$\mathrm{<span\; class="notranslate">\; K</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}^{\mathrm{<span\; class="notranslate">\; L</span>}}{\mathrm{<span\; class="notranslate">\; K</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}<span\; class="notranslate">\; .</span>$

代表基站l在子信道n上的发射功率。这样，用户k的吞吐量则可以表示为该用户在所有分配给它的子信道上的函数，如下公式（1.1）所示：For convenience, in this embodiment, it is assumed that all users and base stations in the multi-cell OFDMA network are single-antenna. The entire multi-cell OFDMA network has N subchannels. L, K and N represent cell set, user set and subchannel set respectively. In addition, let l(k) represent the serving base station of user k, and use represents the channel gain (including path loss, shadowing and small-scale fading) of user k and base station l on subchannel n, with

Represents the transmit power of base station l on subchannel n. In this way, the throughput of user k can be expressed as a function of the user on all subchannels allocated to it, as shown in the following formula (1.1):

${\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; \&Element;</span>{\mathrm{<span\; class="notranslate">\; \&Omega;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; k</span>}}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; SINR</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1.1</span>}<span\; class="notranslate">\; )</span>$

Wherein, Ω _{l(k), k} represents the set of subchannels allocated to user k by the serving base station l(k) of user k. Under the serving base station l(k) of user k, the signal-to-interference-noise ratio of user k is shown in the following formula (1.2):

${\mathrm{<span\; class="notranslate">\; SINR</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; G</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; N</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}_{{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; \&NotEqual;</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; G</span>}}_{{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; k</span>}}^{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}}_{{\mathrm{<span\; class="notranslate">\; 1</span>}}^{<span\; class="notranslate">\; \&prime;</span>}}^{\mathrm{<span\; class="notranslate">\; no</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1.2</span>}<span\; class="notranslate">\; )</span>$

Among them, N ₀ is Gaussian white noise.

In order to eliminate the interference within the cell, in this embodiment, it is required that different users served by the same base station cannot use the same subchannel, that is, in this embodiment, the constraints shown in the following formula (1.3) need to be met:

Ω _{l(k), k} ∩Ω _{l(j), j} = Θ (1.3)

l(k)=l(j)

Based on the above research results and assumptions, embodiments of the present invention propose a resource allocation method suitable for multi-cell OFDMA networks, as shown in Figure 1, the method mainly includes the following steps:

In step 101, each base station in the multi-cell OFDMA network performs single-cell resource allocation on subchannels in its own available subchannel set.

In this step, it may be considered to adopt some existing single-cell resource allocation methods, for example, an adaptive single-cell resource allocation method (Adaptive Radio Resource Allocation Mechanism) and the like. For convenience, in this embodiment, each base station may use a Greedy Algorithm to allocate resources for a single cell. At this time, the process flow of each base station using the greedy algorithm to allocate single-cell resources is shown in Figure 2, and the specific description is as follows: each base station i in the multi-cell OFDMA network assigns each sub-channel in its own available sub-channel set N' To perform single-cell resource allocation on a channel, the following operations are performed respectively:

Step 201: Initialize the set M' of unserved users in the cell where the user is located, making it equal to the set M of users in the cell.

Step 202, for a subchannel n in the available subchannel set N', find user k from the unserved user set M' in the cell where the user is located, so that user k has the largest channel gain on subchannel n, And assign subchannel n to user k.

It should be noted that the above available subchannel set N' is a set of subchannels that the base station i can perform single-cell resource allocation. When the above step 101 is executed for the first time, the available subchannel set N' can be initialized as all subchannel sets N of the base station i in advance; and when the subsequent step 101 is executed again, the available subchannel set N' is the updated subchannel set N' from the base station i In all the subchannel sets N of i, the subchannel sets except the subchannels requiring cooperative transmission by the base station.

Step 203, delete subchannel n from the available subchannel set N', and delete user k from the unserved user set M' in the cell where the user is located;

Step 204, if the unserved user set M' in the own cell is empty, then make the unserved user set M' in the own cell equal to the user set M in the cell;

Step 205, judging whether the available sub-channel set N' is empty, if yes, ending the single cell resource allocation; otherwise, returning to step 202.

It can be seen from the above process that the above single-cell resource allocation method is distributed, and each base station only needs to know the information of users in its own cell. After this step, an initial resource allocation result is obtained.

Step 102, each user in the multi-cell OFDMA network reports to its own serving base station the interference information corresponding to the sub-channel with the strongest interference it receives, specifically including: sub-channel ID, the base station causing the strongest interference to the sub-channel ID of the interfering base station (hereinafter referred to as the interfering base station ID) and the received interference value, such as interference power.

In this step, each user may report the above interference information to its own serving base station through an uplink.

Step 103, after receiving the interference information reported by the user, each base station in the multi-cell OFDMA network selects the S subchannels that suffer the most interference, and sends the interference information corresponding to the S subchannels (including: subchannel ID, The interfering base station ID and the received interference value) are sent to the CU.

It should be noted that the above S is a natural number, which can be a predetermined fixed value, or a value dynamically determined according to the total number of interfered sub-channels reported by the user, for example, it can be set as the interfered sub-channel reported by the user A certain percentage of the total, for example 20%. In this case, the amount of interference information reported by each base station to the CU may or may not be equal.

Step 104, the CU generates an interference list according to the interference information reported by each base station, and the interference list records the IDs of serving base stations and the corresponding interference information (including: subchannel ID, Interfering base station ID and received interference value).

Wherein, the aforementioned serving base station ID is the ID of the base station reporting the interference information to the CU. Table 1 shows an example of an interference list generated by the CU in step 104 above.

serial number Subchannel ID Service base station ID Interference base station ID Interference value 1 ... T

Table 1

Similar to the above S, the above T is also a natural number, which can be a predetermined fixed value, or a value dynamically determined according to the total number of interfered sub-channels reported by the user, for example, set as the interfered sub-channel reported by the user A certain percentage of the total number of channels, for example 10%.

It should be noted that the interference list only records the interference information of the T most interfered sub-channels, and if two adjacent base stations report the interference information of the same sub-channel to the CU at the same time and this sub-channel belongs to the T most interfered The CU selects the interference information with stronger interference and records it in the interference list.

Step 105 , the CU determines the base station for cooperative transmission on each subchannel recorded in the interference list according to the serving base station ID and the interfering base station ID corresponding to each subchannel recorded in the interference list, and notifies the base station for cooperative transmission.

In this step, for a subchannel n recorded on the interference list, assuming that the serving base station is base station i and its interfering base station is base station j, it can be determined that the base stations performing cooperative transmission on subchannel n are base station i and base station j. And it can be determined that base station i and base station j together serve the user who uses subchannel n in the cell corresponding to base station i, and the user who originally used subchannel n in the cell corresponding to base station j will no longer be able to continue to use this channel. In this way, although the channel utilization rate is reduced, the strong interference of base station j to the user using subchannel n in the cell corresponding to base station i can be eliminated through cooperative transmission, thereby improving the signal-to-interference-noise ratio of the user and improving the throughput of the user , thereby improving the throughput of the entire multi-cell OFDMA network.

In addition, with regard to cooperative transmission between base stations, many ways can be used, such as beamforming. In this embodiment, for the sake of convenience, only the superposition of power can be considered, that is, two base stations performing cooperative transmission transmit the same content to the same user, and the signal power of the user being served by cooperation is the signal power obtained from the two base stations. The powers received at the cooperative base stations are summed.

Step 106, each base station performs cooperative transmission on sub-channels that require cooperative transmission according to the instruction of the CU, and deletes these sub-channels that require cooperative transmission from its own sub-channel set N to update its own available sub-channel set N'.

In this step, each base station deletes those subchannels that require cooperative transmission from its own subchannel set N to obtain its own updated available subchannel set N'.

After the above steps 101 to 106 are executed, a round of resource allocation is completed. Next, in the next time slot, return to step 101 for the next round of resource allocation.

Since each base station will update its own available subchannel set N' in the above step 106, the next round of resource allocation will be adjusted on the basis of the previous round of resource allocation results. Therefore, it can be seen that the method of this embodiment is a resource allocation method that is continuously updated according to environmental changes.

From the above description process, it can be seen that the resource allocation method proposed in this embodiment is a distributed resource allocation method, and the CU does not need to know the channel information of all users on all channels in the entire multi-cell OFDMA network, so it is different from the central method It is more suitable for practical application than the resource allocation method. In addition, the complexity of the CU is greatly reduced.

Secondly, in the resource allocation method proposed in this embodiment, the CU can generate an interference list according to the interference information reported by each base station, and further determine base stations for cooperative transmission on some sub-channels with strong interference according to the interference list. Since the existing distributed resource allocation method cannot realize cooperative transmission between base stations, the method proposed in the embodiment of the present invention can improve the whole network while eliminating the strongest interference compared with the existing distributed resource allocation method. The throughput of the network.

Again, in the method described in this embodiment, only a small amount of information needs to be exchanged between the user and the base station, and between the base station and the CU, so there is less signaling overhead.

In addition, the computational complexity of the resource allocation method proposed in the embodiment of the present invention is relatively low, only about O(LMN/2+NlogN).

Finally, in addition to the multi-cell OFDMA network, the resource allocation method of this embodiment can also be applied to a variety of existing network facilities, and can also be combined with technologies such as micro cells and femto cells, and has good compatibility .

Corresponding to the above resource allocation method, the embodiment of the present invention also provides a base station and a CU that should have the above method, wherein the specific structure of the base station is shown in Figure 3, specifically including:

The single-cell resource allocation unit is used to perform single-cell resource allocation on the sub-channels in its own available sub-channel set N'; as mentioned above, but the cell resource allocation unit may consider adopting some existing single-cell resource allocation methods , for example, an adaptive single-cell resource allocation method or a greedy algorithm to allocate resources for a single cell;

The interference information receiving unit is used to receive the interference information corresponding to the sub-channel with the strongest interference reported by the user it serves, specifically including: the sub-channel ID, the ID of the base station that caused the strongest interference to the sub-channel (hereinafter referred to as is the interfering base station ID) and the received interference value, such as interference power, etc.;

The interference information reporting unit is used to select the S subchannels that suffer the most interference from the interference information reported by the users served by itself, and send the interference information corresponding to the S subchannels (including: subchannel ID, interfering base station ID, and received Interference value) sent to the CU; as mentioned above, the above S is a natural number, which can be a predetermined fixed value, or a value dynamically determined according to the total number of interfered sub-channels reported by the user. For example, it can be set as the user A certain percentage of the total number of reported interfered sub-channels, for example 20%; and

The cooperative transmission unit is configured to perform cooperative transmission on the subchannels that require cooperative transmission according to the instructions of the CU, and delete these subchannels that require cooperative transmission from its own subchannel set N to update its own available subchannels Set N'.

The specific structure of the CU is shown in Figure 4, mainly including:

The interference list generation unit is used to generate an interference list according to the interference information reported by each base station, and the interference list records the serving base station IDs and corresponding interference information (including: channel ID, interfering base station ID, and the interference value received); as mentioned above, the above T is also a natural number, which can be a predetermined fixed value, or it can be dynamic according to the total number of interfered sub-channels reported by the user. A determined value, such as being set to a certain percentage of the total number of interfered sub-channels reported by users, such as 10%; and

The cooperative transmission determining unit is configured to determine the base station for cooperative transmission on each subchannel recorded in the interference list according to the serving base station ID and the interfering base station ID corresponding to each subchannel recorded in the interference list, and notify the base station for cooperative transmission.

The technical effect of the resource allocation method in the embodiment of the present invention will be specifically described below through simulation. Table 2 below shows the system parameters used in the simulation.

parameter value Number of cells L 19 Cell radius 500 meters carrier frequency 2GHz bandwidth 10MHz subchannel bandwidth 180kHz path loss 128.1+37.6log10(d)dB Shadowing standard deviation 10dB

Rayleigh fading COST 207,TU Cell edge transmit power 46dBm Transmitting power of cell center 40dBm thermal noise -121dBm

Table 2

Figure 5 shows the average throughput of the cell under different cell loads (number of users) when using different resource allocation methods, where the curve with a star corresponds to the existing centralized resource allocation method; the curve with a square corresponds to The resource allocation method proposed in the embodiment of the present invention; the curve with rhombus corresponds to the existing soft frequency multiplexing resource allocation method; the curve with circle corresponds to the existing Reuse-3 resource allocation method; the curve with triangle corresponds to the existing base station There is no method of collaboration. It can be seen from FIG. 5 that, compared with various existing distributed resource allocation methods, the resource allocation method proposed in the embodiment of the present invention can improve the average throughput of the cell.

It can be seen from the previous description that in the solutions described in the embodiments of the present invention, new signaling needs to be added between the user and the base station to transmit the interference information of the user. In order not to add new signaling, the embodiment of the present invention also proposes an alternative solution, that is, using the signal-to-interference-noise ratio of the user's own subchannel and the reference signal received power of the adjacent cell reported by the user to the serving base station as the above-mentioned user Interference information reported to the base station. Specifically, the user first reports its SINR on each subchannel and the Reference Signal Received Power (RSRP) of each base station to the base station through the existing measurement (measurement) process and signaling; Select S subchannels with the smallest SINR from its own subchannels, and combine the subchannel IDs corresponding to these S subchannels, the ID of the base station corresponding to the strongest reference signal receiving power except itself, and the reference signal receiving power of the base station The power is sent to the central controller CU as the sub-channel ID, interfering base station ID and interference value in the interference information; next, the CU generates an interference list according to the information reported by the base station, and its structure is also shown in Table 1, mainly including: Channel ID, serving base station ID, interfering base station ID and interference value. Then, the CU can directly determine the subchannel for cooperative transmission and the base station for cooperative transmission according to the interference list, and notify the corresponding base station. Since the user reports the SINR to its serving base station and the RSRP of each base station uses existing signaling, no new signaling is needed in this alternative solution.

In this case, the structure of the base station implementing the above method is also shown in Figure 3, mainly including the following components:

a single-cell resource allocation unit, configured to perform single-cell resource allocation on subchannels in its own set of available subchannels;

The interference information receiving unit is used to receive the signal-to-interference-noise ratio on all sub-channels reported by the user served by itself and the reference signal received power from each base station;

The interference information reporting unit is used to select S subchannels with the smallest signal-to-interference-noise ratio from its own subchannels, and report the subchannel IDs corresponding to these S subchannels and the base station corresponding to the strongest reference signal received power other than itself The ID and the reference signal received power of the base station are sent to the central controller CU as the subchannel ID, the interfering base station ID and the interference value in the interference information; wherein, the S is a natural number; and

The cooperative transmission unit is configured to perform cooperative transmission on the subchannels that require cooperative transmission according to the instructions of the CU, and delete these subchannels that require cooperative transmission from its own subchannel set to update its own available subchannel set .

Those skilled in the art can understand that the advantage of this alternative solution is that signaling overhead is saved, but

Yes, since the poor signal-to-interference-noise ratio may be caused by small channel gain rather than large interference, therefore,

The performance of this alternative is not comparable to that described in the above examples.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the present invention. within the scope of protection.

Claims (12)

1. a resource allocation methods is characterized in that, comprising:

Each base station is distributed the resource that the subchannel in the set of self available subchannels carries out single residential quarter respectively;

Each user is disturbed interfere information corresponding to the strongest subchannel to the serving base stations report self of self respectively; Wherein, described interfere information comprises: subchannel sign ID, interference base station ID and suffered interference value;

Each base station therefrom select respectively the maximum S sub-channels that is interfered, and the interfere information that this S sub-channels is corresponding sends to master controller CU after receiving the interfere information of reporting of user; Wherein, described S is natural number;

The interfere information that CU reports according to each base station generates one and disturbs tabulation, records serving BS ID and the corresponding interfere information thereof of the maximum T sub-channels that is interfered; Wherein, described T is a natural number;

CU determines that according to disturbing corresponding serving BS ID and the interference base station ID of each sub-channels that record of tabulation institute each sub-channels that records carries out the base station that cooperation is transmitted in disturbing tabulation, and notifies the base station of cooperating and transmitting; And

Each base station is according to the instruction of CU, in the needs subchannel of the transmission transmission of cooperating of cooperating, and these subchannels that need to cooperate transmission deleted from the sets of sub-channels of self with the available subchannels of upgrading self gather.

2. a resource allocation methods is characterized in that, comprising:

Each base station is distributed the resource that the subchannel in the set of self available subchannels carries out single residential quarter respectively;

Each user is the Signal to Interference plus Noise Ratio on all subchannels of serving base stations report self of self and from the Reference Signal Received Power of each base station respectively;

The subchannel of S Signal to Interference plus Noise Ratio minimum is selected respectively in each base station from the subchannel of self, and the subchannel ID that this S sub-channels is corresponding, the ID of the strongest Reference Signal Received Power institute respective base station and the Reference Signal Received Power of this base station send to master controller CU as the subchannel ID in the interfere information, interference base station ID and interference value except self; Wherein, described S is natural number;

The interfere information that CU reports according to each base station generates one and disturbs tabulation, records serving BS ID and the corresponding interfere information thereof of the maximum T sub-channels that is interfered; Wherein, described T is a natural number;

CU determines that according to disturbing corresponding serving BS ID and the interference base station ID of each sub-channels that record of tabulation institute each sub-channels that records carries out the base station that cooperation is transmitted in disturbing tabulation, and notifies the base station of cooperating and transmitting; And

Each base station is according to the instruction of CU, in the needs subchannel of the transmission transmission of cooperating of cooperating, and these subchannels that need to cooperate transmission deleted from the sets of sub-channels of self with the available subchannels of upgrading self gather.

3. method according to claim 1 and 2, it is characterized in that the resource that single residential quarter is carried out to the subchannel in the set of self available subchannels respectively in each base station is distributed and comprised: each base station adopts respectively the single cell resource allocation method of self adaptation to carry out single local resource to distribute.

4. method according to claim 1 and 2 is characterized in that, the resource that single residential quarter is carried out to the subchannel in the set of self available subchannels respectively in each base station is distributed and comprised: the resource that each base station adopts respectively greedy algorithm to carry out single residential quarter is distributed.

5. method according to claim 1 and 2 is characterized in that, described S and T are a predetermined fixing numerical value; Perhaps be the dynamic value of determining of the subchannel that is interfered sum according to reporting of user.

6. method according to claim 5 is characterized in that, described S and T are set to the certain proportion of the subchannel sum that is interfered of reporting of user.

7. method according to claim 1 and 2, it is characterized in that, further comprise: if two adjacent base stations report the interfere information of same subchannel and this sub-channels to belong to T subchannel that disturbs maximum to CU simultaneously, then CU therefrom selects wherein to disturb stronger interfere information to be recorded in the interference tabulation.

8. method according to claim 1 and 2, it is characterized in that, described CU according to disturb tabulation corresponding serving BS ID and the interference base station ID of each sub-channels that records, determine that the base station that in disturbing tabulation each sub-channels that record carries out the cooperation transmission comprises: for disturbing a sub-channels n who tabulates and record, suppose that serving BS is base station i, its interference base station is base station j, then determine subchannel n cooperate the transmission the base station be base station i and base station j; And base station i and base station j together serve that user who uses subchannel n in base station i institute respective cell.

9. method according to claim 1 and 2 is characterized in that, further comprises: at next time slot, return each base station and respectively the subchannel in the set of self available subchannels is carried out the step that the resource of single residential quarter distributes and continue to carry out.

10. a base station is characterized in that, comprising:

Single local resource allocation units are used for the subchannel that the available subchannels of self is gathered is carried out the resource distribution of single residential quarter;

The interfere information receiving element, its that be used for to receive that self institute's service-user reports is disturbed interfere information corresponding to the strongest subchannel; Wherein, described interfere information comprises: subchannel sign ID, interference base station ID and suffered interference value;

Interfere information reports the unit, be used for selecting the maximum S sub-channels that is interfered from the interfere information that self institute's service-user reports, and the interfere information that this S sub-channels is corresponding sends to master controller CU; Wherein, described S is natural number; And

The cooperation transmission unit is used for the instruction according to CU, in the needs subchannel of the transmission transmission of cooperating of cooperating, and these subchannels that need to cooperate transmission is deleted from the sets of sub-channels of self with the available subchannels of upgrading self gather.

11. a base station is characterized in that, comprising:

Single local resource allocation units are used for the subchannel that the available subchannels of self is gathered is carried out the resource distribution of single residential quarter;

The interfere information receiving element, the Signal to Interference plus Noise Ratio on self all subchannel that be used for to receive that self institute's service-user reports and from the Reference Signal Received Power of each base station;

Interfere information reports the unit, be used for selecting from the subchannel of self subchannel of S Signal to Interference plus Noise Ratio minimum, and the subchannel ID that this S sub-channels is corresponding, the ID of the strongest Reference Signal Received Power institute respective base station and the Reference Signal Received Power of this base station send to master controller CU as the subchannel ID in the interfere information, interference base station ID and interference value except self; Wherein, described S is natural number; And

The cooperation transmission unit is used for the instruction according to CU, in the needs subchannel of the transmission transmission of cooperating of cooperating, and these subchannels that need to cooperate transmission is deleted from the sets of sub-channels of self with the available subchannels of upgrading self gather.

12. a master controller CU is characterized in that, comprising:

Disturb the generation unit of tabulating, the interfere information that is used for reporting according to each base station generates one and disturbs tabulation, records serving BS ID and the corresponding interfere information thereof of the maximum T sub-channels that is interfered; Wherein, described T also is a natural number; And

Cooperation transmission determining unit is used for determining that each sub-channels that records carries out the base station that cooperation is transmitted in disturbing tabulation, and notifying the base station of cooperating and transmitting according to disturbing corresponding serving BS ID and the interference base station ID of each sub-channels that record of tabulation institute.

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