Low power, short range point-to-multipoint communications system

• US 6,553,239 B1
• Filed: 07/27/2000
• Issued: 04/22/2003
• Est. Priority Date: 06/07/1995
• Status: Expired due to Term

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Langston, J. Leland
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Moore, James K
• Application Number:
  US09/626,971
• Time in Patent Office: 999 Days
• Field of Search: 455/62, 455/63, 455/67.1, 455/25, 455/101, 455/103, 455/60, 455/422, 455/517, 455/524, 455/561, 455/562, 455/41, 343/853, 343/797, 343/891, 343/890, 348/6, 342/361, 342/362, 342/363, 342/364, 342/365, 342/366
• US Class Current: 455/562.1
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 52/0203 in the radio access network or backbone network of wireless communication networks
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A point-to-multipoint or two-way communications system is provided by a nodal transmitter located in a node with a plurality of nodal antennas radiating different polarization signals about the node. The system includes subscriber stations with directional antennas adapted to receive signals radiated from the nodal transmitter. The system may additionally include capability for transmitting and radiating subscriber signals to the nodal transmitter location for two-way communications.

Claims

1. A transmitter system for a short range wireless point to multi-point communications system, comprising:

a transmitter operable to broadcast a plurality of channels over a given frequency band, each channel associated with a different one of a plurality of sub-frequency bands of the frequency band;

a plurality of transmitting antennas, each transmitting antenna including a plurality of linear arrays, each linear array having a plurality of radiating elements and a plurality of exciter stubs, each exciter stub being aligned with an associated radiating element, each linear array associated with a different one of the plurality of channels to broadcast information over an associated sub-frequency band of the frequency band, each of the plurality of transmitting antennas having a polarization type different than that of an adjacent transmitting antenna, wherein each exciter stub and associated radiating element are spaced to control a phase between radiating elements.

2. The transmitter system of claim 1, wherein the sub-frequency bands are contiguous to each other.

3. The transmitter system of claim 1, wherein the transmitter includes a plurality of multiplexers, each multiplexer operable to time multiplex channel information for a corresponding channel onto an output stream.

4. The transmitter system of claim 3, wherein the transmitter includes a plurality of modulators, each modulator operable to modulate the channel information for a corresponding channel.

5. The transmitter system of claim 3, wherein the transmitter includes a plurality of up-converters, each up-converter operable to up-convert a corresponding channel to a millimeter frequency.

6. The transmitter system of claim 3, wherein the transmitter includes a plurality of encoders, each encoder operable to perform forward error correction on a corresponding channel.

7. The transmitter system of claim 1, wherein the transmitter includes a plurality of amplifier systems, each amplifier system operable to provide linear amplification to a corresponding channel in order to prevent intermodulation distortion from interfering with other channels.

8. The transmitter system of claim 7, wherein each amplifier system includes a plurality of amplifiers, each amplifier associated with a corresponding radiating element.

9. The transmitter system of claim 1, wherein the transmitter includes a compression unit operable to compress the channel information in order to reduce a number of the plurality of channels required for communication.

10. The transmitter system of claim 1, wherein information for each channel is provided by a central office.

11. A method for providing short range wireless point to multi-point communications, comprising:

receiving channel information corresponding to a plurality of channels;

placing the channel information into the plurality of channels;

associating each of the plurality of channels with a different sub-frequency band of a given frequency band;

polarizing each of a plurality of transmitting antennas such that each transmitting antenna has a polarization type which is different than a polarization type of an adjacent transmitting antenna;

aligning one of a plurality of exciter stubs with an associated one of a plurality of radiating elements in each transmitting antenna;

spacing the plurality of exciter stubs and associated radiating elements in each transmitting antenna to control a phase between radiating elements;

transmitting the plurality of channels over the plurality of transmitting antennas at the given frequency band.

12. The method of claim 11, wherein the plurality of transmitting antennas are orthogonally polarized.

13. The method of claim 11, further comprising:

multiplexing the channel information onto an associated channel.

14. The method of claim 11, further comprising:

modulating each channel.

15. The method of claim 11, further comprising:

up-converting each channel to an appropriate millimeter frequency.

16. The method of claim 11, further comprising:

amplifying each channel according to linear amplification techniques in order to prevent intermodulation distortion from interfering with other channels.

17. The method of claim 11, further comprising:

compressing the channel information to reduce a number of the plurality of channels.

18. The method of claim 11, further comprising:

performing forward error correction on each channel.

19. The method of claim 11, wherein the channel information is received through microwave transmission.

20. The method of claim 11, wherein the channel information is received through fiber optic transmission.