Method and apparatus for interference-aware resource-sharing scheme for multiple D2D group communications underlaying cellular networks

1. A method for interference-aware resource-sharing scheme for multiple device-to-device (D2D) communications, the method comprising:

initializing the D2D communication request and deciding the number of D2D pairs and cellular users (CUEs);

grouping D2D pairs according to the decided number of the D2D pairs and CUEs;

selecting target CUEs for the grouped D2D pairs to share frequency resources;

applying interference alignment to the D2D groups;

updating the set of CUEs and D2D pairs;

moving the rest of the D2D pairs to orthogonal group.

2. The method of claim 1 , wherein the initializing of the D2D communication request and the deciding of the number of the D2D pairs and CUEs comprises:

determining whether 3≤L max ≤N and if 3≤L max ≤N, determining whether the number of the CUEs is zero;

determining whether 3≤N≤L max and if 3≤N≤L max , determining whether the number of CUEs is zero;)

determining whether 0<N≤2 and if 0<N≤2, determining whether the number of the CUEs is zero;

if N=0, terminating the process of interference-aware resource-sharing scheme for the multiple D2D group communications,

wherein N is an integer greater than or equal to 0 as the number of D2D pairs, and L max is an integer greater than or equal to 3 as a predetermined upper bound of the number of D2D pairs.

3. The method of claim 2 , wherein the grouping of D2D pairs according to the decided number of the D2D pairs and CUEs comprises:

if 3≤L max ≤N and unless the number of the CUEs is zero, selecting two nearest D2D pairs as the first D2D pair and the second D2D pair and selecting other D2D pairs until an L max 'th D2D pair in the order of distance;

if 3≤N≤L max and unless the number of the CUEs is zero, selecting two nearest D2D pairs as the first D2D pair and the second D2D pair and selecting other D2D pairs until the N'th D2D pair in the order of distance;

if 0<N≤2 and unless the number of the CUEs is zero, selecting one D2D pair and calculating angles between the D2D pair and all of the CUEs.

4. The method of claim 1 , wherein the selecting of the target CUEs for the grouped D2D groups to share frequency resources comprises:

calculating angles between the D2D pair and all of the CUEs and if the angles satisfy the condition, selecting corresponding CUEs for frequency resource-sharing candidates, and calculating distances between the D2D pair and the CUEs that are selected as the resource-sharing candidates.

5. The method of claim 4 , wherein if the angles disagree with the condition, the corresponding D2D moves to the orthogonal group.

6. The method of claim 3 , wherein, if 0<N≤2 and unless the number of the CUEs is zero, the selecting of said one D2D pair, and the calculating of the angles between the D2D pair and all of the CUEs comprises:

if the angles satisfies the condition, selecting corresponding CUEs for frequency resource-sharing candidates and calculating distances between the D2D pair and the CUEs that are selected as the resource-sharing candidates.

7. The method of claim 6 , wherein if the angles dissatisfy with the condition, a corresponding D2D moves to the orthogonal group.

8. The method of claim 1 , wherein the updating of the set of the CUEs and the D2D pairs comprises:

finding a CUE, which has the furthest distance from the D2D pairs, and selecting the CUE for sharing frequency resources with the D2D pairs.

9. The method of claim 1 , wherein the moving of the rest of the D2D pairs to the orthogonal group comprises:

moving the rest of the D2D pairs, which are permitted to use independent and periodic frequency resources, and performing the PF scheduling in consideration for the resource allocation among the D2D pairs.

10. An apparatus for interference-aware resource-sharing for multiple group communications, the apparatus comprising:

an initializing and detecting part configured to initialize a device-to-device (D2D) communication request and to decide the number of D2D pairs and cellular users (CUEs);

a grouping part configured to group D2D pairs according to the decided number of the D2D pairs and CUEs;

a selecting part configured to select target CUEs for the grouped D2D pairs to share frequency resources;

an interference removing part configured to apply interference alignment to the D2D groups;

an updating part configured to update a set of the CUEs and D2D pairs;

a sharing part configured to move the rest of the D2D pairs to the orthogonal group.