Antenna system for a cellular telephone network

• US 5,983,118 A
• Filed: 06/12/1997
• Issued: 11/09/1999
• Est. Priority Date: 04/02/1991
• Status: Expired due to Term

• Current Assignee: Cellco Partnership, Inc. (Verizon Communications Inc.)
• Original Assignee: Airtouch Communications, Inc. (Vodafone Group PLC)
• Inventors: Lee, William Chien-Yeh
• Primary Examiner(s): Le, Thanh Cong
• Application Number:
  US08/873,756
• Time in Patent Office: 880 Days
• Field of Search: 455/426, 455/436, 455/432, 455/433, 455/434, 455/435, 455/450, 455/452, 455/453, 455/455, 455/456, 455/457, 455/458, 455/507, 455/517, 455/524, 455/62, 455/67.1, 455/550 , 455/560, 455/561, 455/562, 455/575, 455/FOR 100, 455/FOR 101, 455/FOR 102, 455/FOR 113-115, 370/329, 370/331, 370/334
• US Class Current: 455/562.1
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0491 using two or more sectors, i.e. sector diversity
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0837 using pre-detection combining H04B7/0868 takes precedence
• CPC Class Codes: H04B 7/26 at least one of which is mobile
• CPC Class Codes: H04W 16/00 Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A cellular telephone system is described of the type wherein a plurality of contiguous cells, each having an assigned set of identification codes, are arranged with means for maintaining continuous communication with mobile telephones moving from cell to cell. The system allows multiple access by including means for assigning at least one of the in the assigned set of identification codes to more than one mobile telephone. A unique identification code is assigned to a mobile telephone located in the cell. A signal having a unique identification code is generated for identifying the mobile telephone. The signal is coupled to the zones. A combiner is also provided for combining signals from all of the zones in the cell. A receiver is coupled to the combiner for retrieving the signals having the code. According to another aspect of the invention, the signal coupled to the zones is delayed so that the transmission of the signal among the plurality of antenna sets is delayed by a preselected amount so as to reduce interference caused by successive reception of signals.

Claims

1. An antenna system for a cellular telephone system, wherein the cellular telephone system comprises a plurality of cells, each of the cells being comprised of at least one zone, each of the cells having an assigned set of identification codes, and each of the identification codes being used to encode radio frequency (RF) signals communicated to a mobile telephone within the cell, comprising:

a plurality of antennae coupled to a transceiver for transmitting and receiving the RF signals at assigned frequencies for communicating with mobile telephones within the cell, wherein a plurality of the mobile telephones simultaneously use an identical assigned frequency and a different one of the identification codes assigned to the cell;

a directionality apparatus, coupled to the antennae, for maintaining communications with the mobile telephones by selectively coupling the transceiver to the antennae as the mobile telephones move about the cell while using the same identification codes for each of the mobile telephones; and

circuitry, coupled to the antennae, for maintaining communications with the mobile telephones by changing the identification codes for each of the mobile telephones as they move from cell to cell.

2. The antenna system of claim 1, wherein the directionality apparatus selectively couples more than one antennae in the cell to the transceiver.

3. The antenna system of claim 1, wherein the directionality apparatus selectively couples more than one antennae in the zone to the transceiver.

4. The antenna system of claim 1, wherein the antennae for the cell are located within the cell.

5. The antenna system as set forth in claim 1, wherein the antenna is located on a periphery of the zone and is pointed into the zone to substantially limit propagation of signals to the zone.

6. The antenna system as set forth in claim 1, wherein the directionality apparatus further comprises:

a monitor for measuring one or more characteristics of a signal received by the antennae; and

a switch/combiner for selectively coupling the transceiver to the antennae based on the measured characteristic.

7. The antenna system as set forth in claim 1, wherein the zones are arranged in a manner to create linear coverage for the cell.

8. A method for communicating within a cellular telephone system, comprising the steps of:

dividing an area into cells, each cell having a transceiver and a plurality of antennae;

dividing each cell into zones, each cell containing at least one zone;

assigning a set of frequencies and a set of identification codes to each cell, each of the identification codes being used to encode radio frequency (RF) signals communicated to a mobile telephone within the cell;

coupling the antennae to the transceiver;

transmitting and receiving the RF signals from the transceiver to the mobile telephones at the assigned frequencies for the cell, wherein a plurality of the mobile telephones simultaneously use an identical assigned frequency and a different one of the identification codes assigned to the cell;

selectively coupling the antennae to the transceiver to maintain communications between the transceiver and the mobile telephones as the mobile telephones move about the cell while using the same identification codes for each of the mobile telephones; and

changing the identification codes for each of the mobile telephones as they move from cell to cell to maintain communications with the mobile telephones.

9. The method of claim 8, wherein the step of selectively coupling couples more than one antenna in the cell to the transceiver.

10. The method of claim 8, wherein the antenna for the cell are located within the cell.

11. The method of claim 8, wherein the antenna is located on a periphery of the zone and is pointed into the zone to substantially limit propagation of signals to the zone.

12. The method of claim 8, further comprising the steps of:

monitoring the signal received by the antenna for one or more characteristics of the signal; and

selectively coupling the transceiver to at least one antenna based on the measured characteristic.

13. An antenna system for a cellular telephone system, wherein the cellular telephone system comprises a plurality of cells, each of the cells having an assigned set of identification codes, and each of the identification codes being used to encode radio frequency (RF) signals communicated to a mobile telephone within the cell, comprising:

a first antenna and a second antenna, coupled to a transceiver for transmitting and receiving the RE signals at assigned frequencies for communicating with mobile telephones within the cell, wherein a plurality of the mobile telephones simultaneously use an identical assigned frequency and a different one of the identification codes assigned to the cell;

means, coupled to the first antenna and second antenna, for measuring one or more characteristics of a signal received by the first antenna and the second antenna;

means, coupled to the antenna, for selecting the first antenna and the second antenna and for coupling the first antenna and the second antenna to the transceiver to maintain communications with the mobile telephones as the mobile telephones move about the cell while using the same identification codes for each of the mobile telephones, the selection and coupling of the first and second antenna based on the measured characteristic; and

means, coupled to the antenna, for maintaining communications with the mobile telephones by changing the identification codes for each of the mobile telephones as they move from cell to cell.

14. The antenna system of claim 13, wherein the first antenna and the second antenna are co-located.

15. The antenna system of claim 14, wherein the first antenna and the second antenna are co-located within the cell.

16. The antenna system of claim 13, wherein the first antenna and the second antenna are not co-located.

17. The antenna system as set forth in claim 13, wherein the means for coupling further comprises:

means for monitoring or more characteristics of a signal received by the first antenna and the second antenna; and

means for selectively coupling the transceiver to the first antenna and the second antenna based on the measured characteristic.