# US 2014/0155079 A1 · Method for spectrum allocation based on interference suppression and user difference bandwidth requirements

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- Number: US 2014/0155079 A1
- Document ID: US20140155079A1
- Status: Published application
- Kind: A1
- Application number: 13/907,448
- Filed: 2013-05-31
- Published: 2014-06-05
- Earliest claimed: 2012-12-04
- Assignees: Beijing University of Posts and Telecommunications
- Inventors: Xiaodong Xu; Xiaofeng Tao; Zhou Xu; Huixin Zhang; Ping Zhang
- Web page: https://patentgrep.com/patent/US20140155079A1

## CPC

- H04L 5/0073: {Allocation arrangements that take into account other cell interferences}
- H04L 5/0037: {Inter-user or inter-terminal allocation}
- H04L 5/0064: {Rate requirement of the data, e.g. scalable bandwidth, data priority}
- H04L 5/0067: {Allocation algorithms which involve graph matching}
- H04L 5/0075: {Allocation using proportional fairness}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

The present invention relates to the technical field of wireless communication and of mobile communication, and more particularly to a method for spectrum resource allocation and interference avoidance of femtocell in a heterogeneous environment consisting of macro cell and femtocell, and specifically to a spectrum allocation method based on interference suppression and user difference bandwidth requirements. According to the spectrum allocation method based on interference suppression and user difference bandwidth requirements of the present invention, spectrum resource can be allocated reasonably according to the priority level of bandwidth requirements in combination with graph coloring algorithm and chromaticity preference algorithm. In this manner, in-layer interference among femtocells and cross-layer interference among femtocells and macro cells can be effectively suppressed, the difference bandwidth requirements of femtocell users can be satisfied, and the efficiency of frequency utilization and the whole throughput of system can be also optimized to the maximum extent.

## Claims

### Claim 1

A spectrum allocation method based on interference suppression and user difference bandwidth requirements, comprising:
Step 1, collecting overhead information detected by femtocell users in a regular manner;
Step 2, establishing an interference topology graph based on the overhead information and determining an available spectrum resource set;
Step 3, coloring the interference topology graph based on the priority level of bandwidth requirements of the femtocell users through chromaticity preference algorithm; and
Step 4, according to the coloring results from Step 3, establishing a corresponding relationship between available spectrum resource set and color so as to allocate spectrum resource to the femtocell users.

### Claim 2 (depends on 1)

The method of claim 1, wherein the overhead information comprises the spectrum resource occupation status of a macro cell where the femtocell users are located and the ID numbers of neighboring femtocells that may be suffered from co-channel interference.

### Claim 3 (depends on 1)

The method of claim 1, wherein in Step 2, the bandwidth requirements are classified into a plurality of priority levels according to different bandwidth usage of the femtocell users.

### Claim 4 (depends on 3)

The method of claim 3, wherein in Step 2, the bandwidth requirements are classified into two priority levels according to different bandwidth usage of the femtocell users.

### Claim 5 (depends on 1)

The method of claim 1, wherein Step 2 further comprises:
Step 201, establishing an interference topology graph, wherein each node represents a femtocell and the connecting line between nodes represents that use of co-channel signal will generate interference in the femtocells connected by the connecting line; and
Step 202, the topology graph consisting of a plurality of clusters which are not connected with each other; defining the number of the nodes in a cluster as N, then a set consisting of all nodes in the cluster is V={v1, v2, . . . , vN}N×1 defining the available spectrum detected by node vm is Im, then the available spectrum in the cluster is
I
=
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m
=
1
m
=
N
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I
m
,
wherein the available spectrum of all clusters forms an available spectrum resource set.

### Claim 6 (depends on 5)

The method of claim 5, wherein Step 3 further comprises
Step 301, calculating degree of each node in a cluster, and adding all the nodes in the cluster into set U;
S302, allocating a color notation to the node with the largest degree in set U according to the priority level of bandwidth requirements so as to complete coloring, and then removing the node from set U;
S303, calculating the chromaticity value of the nodes not being colored in Set U, selecting a node with the largest chromaticity value therefrom, coloring said node according to the bandwidth requirement priority level based on the lowest color notation, and removing said node from set U after coloring;
S304, if set U is empty, proceeding to Step 4; otherwise, proceeding to Step 303.

### Claim 7 (depends on 6)

The method of claim 6, wherein Step 303 comprises, if there exists more than one nodes with the largest chromaticity value, selecting the node with the largest degree therefrom.

### Claim 8 (depends on 6)

The method of claim 6, wherein coloring said node according to the bandwidth requirement priority level based on the lowest color notation of Step 303 further comprises:
determining whether all the neighboring cells of said node are colored by the color with a color notation j;
if yes, coloring said node with the color notation j and the bandwidth requirement priority level;
if not, modifying the value of j to j+1, and repeating the above steps, wherein the initial value of j is 1.

### Claim 9 (depends on 6)

The method of claim 6, wherein the coloring result includes the largest color notation, the color usage frequency matrix and the coloring recording matrix that are used during coloring.

### Claim 10 (depends on 6)

The method of claim 6, wherein establishing a corresponding relationship between available spectrum resource set and color of Step 4 further comprises:
Step 401, setting a proportion adjusting factor λ;
Step 402, dividing the available spectrums of all clusters into K groups according to proportion λ+c1:λ+c2: . . . :λ+cK, wherein K represents the largest color notation during the coloring of the cluster, and ci represents the usage frequency of the ith color during the coloring of the cluster.