Cellular frequency reuse cell plan

• US 5,247,699 A
• Filed: 04/12/1990
• Issued: 09/21/1993
• Est. Priority Date: 04/12/1990
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hartman, Paul A.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): FAILE, ANDREW I
• Application Number:
  US07/508,921
• Time in Patent Office: 1,258 Days
• Field of Search: 455/33, 455/33.1, 455/33.2, 455/33.3, 455/33.4, 379/58-60
• US Class Current: 455/447
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/32 Hierarchical cell structures

Abstract

A frequency reuse plan for a cellular radio communications system includes a plurality of antenna sites which implement twelve groups of frequencies among four antenna sites. The same frequencies are reused by other groups of four antenna sites. Each antenna site serves three hexagon shaped cells arranged in a clover-leaf shaped pattern by three groups of antennas, each of which group is separated by a pointing angle of 120 degrees.

Claims

1. In a cellular radio communications system including a plurality of radio transceivers each of which are connected to antennas for communicating with a plurality of mobile subscriber units operating within said system, an antenna system comprising:

a plurality of antenna sites spaced from one another throughout said system in a predetermined repeating pattern, each of said antenna sites operating on a specific group of radio frequencies to serve an associated plurality of hexagon-shaped cells within said system and in which no two contiguous sites use the same group of frequencies but frequency groups are reused among arrays of four sites; and

means for implementing twelve groups of frequencies among each of said arrays of four antenna sites where each of said twelve groups of frequencies is comprised of N/12 channels, where N is the number of available voice channel frequencies in the cellular system.

2. A system as recited in claim 1, wherein each site lies along a first generally linear path extending in a first direction, comprising an i shift parameter direction, said first linear path being laterally spaced from adjacent generally parallel linear paths on which other sites are positioned, said sites being located on said parallel paths at positions intersected by second generally linear parallel paths extending in a second direction and extending at a non-orthogonal angle to said first direction, comprising a j shift parameter direction, and with each most nearly adjacent site which reuses the same frequencies being spaced from one another a first selected distance in said first i shift parameter direction and a second selected distance in a second j shift parameter direction, both distances being expressed in terms of integral multiples of the distance along said first and second directions between each adjacent site without regard to the frequencies used thereby, and wherein the shift parameter distances, i and j, between sites which reuse the same frequencies are two and zero, respectively.

3. A system as recited in claim 1, wherein said associated plurality of hexagon-shaped cells comprises a group of three cells.

4. A system as recited in claim 3, wherein each group of three cells is served by three groups of antennas mounted at a pointing angle of 120 degrees to one another.

5. A system as recited in claim 3, wherein said three hexagon-shaped cells in each group are arranged in a cloverleaf fashion with one side of each cell being generally contiguous to one side of each of the other two cells in said group and said antenna site being generally located at the point of intersection of each of said contiguous sides.

6. A system as recited in claim 1 wherein said specific group of frequencies in use at each site are divided into three frequency sub-groups, each sub-group containing 1/12 of the total number of said available voice channel frequencies in the system.

7. A system as recited in claim 4, wherein each of said three groups of antennas comprises at least one 60°

transmit antenna and two diversity receive antennas all with the same pointing azimuths.

8. In a cellular radio communications system including a plurality of radio transceivers each of which are connected to antennas for communicating with a plurality of mobile subscriber units operating within said system, an antenna system comprising:

a plurality of antenna sites spaced from one another throughout said system in a predetermined repeating pattern, each of which sites including antennas operating on a specific group of radio frequencies and each of which antenna sites serve an associated three hexagon-shaped cells within said system and in which no two contiguous sites use the same group of frequencies but frequency groups are reused among individual arrays of four sites; and

means for implementing twelve groups of frequencies among each of said arrays of four antenna sites, each of said twelve groups consisting of N/12 channels, where N is the number of available frequencies in the system.

9. A system as recited in claim 8, wherein each antenna site is spaced from its adjacent site a first selected distance in a first i shift parameter direction and a second selected distance in a second j shift parameter direction at a non-orthogonal angle to said first i shift parameter direction, each of said sites being in linear alignment with other sites in the i direction, and wherein the sites which reuse the same frequencies are spaced from one another in the i shift parameter direction two time said first selected distance.

10. A system as recited in claim 8, wherein each of said associated three cells are served by a group of at least three antennas.

11. A system as recited in claim 10, wherein each group of three cells is served by groups of at least three antennas with each group mounted at a pointing angle of 120 degrees to one another.

12. A system as recited in claim 10, wherein said three cells in each group are arranged in a cloverleaf fashion with one side of each cell being generally contiguous to one side of each of the other two cells in said group and said site being generally located at the point of intersection of each of said contiguous sides.

13. A system as recited in claim 11, wherein each of said three groups of antennas comprises at least one 60°

transmit antenna and at least two diversity receive antennas all with the same pointing azimuths.