Wireless communication system having antenna diversity

• US 5,491,723 A
• Filed: 04/14/1994
• Issued: 02/13/1996
• Est. Priority Date: 05/06/1993
• Status: Expired due to Term

• Current Assignee: NCR Corporation
• Original Assignee: NCR Corporation
• Inventors: Diepstraten, Wilhelmus J. M.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Le, Amanda T.
• Application Number:
  US08/209,099
• Time in Patent Office: 670 Days
• Field of Search: 455/52.1, 455/52.2, 455/52.3, 455/73, 455/78, 455/82, 455/89, 455/269, 455/277.1, 455/277.2, 455/13.3, 455/19, 455/83, 455/24, 455/33.3, 455/54.1, 455/54.2, 455/101 , 455/69, 375/100, 375/267, 375/299, 375/347, 370/32, 370/38, 370/24, 343/876
• US Class Current: 375/267
• CPC Class Codes: H04B 7/061 using feedback from receiving side
• CPC Class Codes: H04B 7/0811 during preamble or gap period

Abstract

A wireless communication system includes a plurality of stations each having a plurality of antennas. A first packet, containing a training signal portion is transmitted from a transmitting station using a first selected antenna and received at a receiving station using a second selected antenna which is selected as the antenna giving the best received signal quality, determined during the training signal period. Following transmission of the first packet, a control signal (ACKCNTL) is generated in both the transmitting station and the receiving station to condition these stations for the transmission from the receiving station of a response packet via the same antenna pair used for the information packet transmission. Thus, the response packet need have only a relatively short training signal portion.

Claims

1. A wireless communication system, comprising:

a first station having a first plurality of antennas, said first station further having a first antenna select switching means which is controlled to select a default antenna of the first plurality of antennas for transmitting an information packet; and

a second station having a second plurality of antennas, said second station further having a second antenna select switching means which is controlled to select a second antenna of the second plurality of antennas to receive the transmitted information packet at said second station,

wherein said second switching means is controlled to enable transmission of a response packet utilizing said second antenna after receipt of the transmitted information packet in response to the second antenna being selected to receive the transmitted information packet, and

wherein said first switching means is controlled to enable receipt of the transmitted response packet utilizing said default antenna in response to the default antenna being selected to transmit the information packet.

2. A wireless communication system according to claim 1, wherein said information packet includes a training signal portion having a first duration, and said response packet includes a training signal portion having a second duration which is less than the first duration.

3. A wireless communication system according to claim 1, wherein said first station includes a first switch control means adapted to control the operation of the first antenna select switching means, and wherein said second station includes a second switch control means adapted to control the operation of the second antenna select switching means, and further wherein a control signal is adapted to be generated in each of said first and second stations for application to the respective first or second switch control means thereof, for conditioning the respective first or second station for receipt or transmission respectively of said response packet.

4. A wireless communication system according to claim 3, wherein said control signal is generated in response to completion of transmission of said information packet.

5. A wireless communication system according to claim 1, wherein said response packet is an acknowledgment packet.

6. A method of operating a wireless communication system having a plurality of stations with each station having a plurality of antennas, comprising the steps of:

identifying a default antenna within a first plurality of antennas at a first station;

selecting the default antenna for transmitting a first packet from the first station;

selecting a second antenna of a second plurality of antennas at a second station for receiving the first packet at the second station, wherein the second antenna selecting step comprises the step of testing received signal quality of the first packet on each of the second plurality of antennas at the second station in order to determine on which antenna to receive the first packet;

transmitting the first packet from the default antenna at the first station and receiving the first packet with the second antenna at the second station;

in response to the second antenna being selected in the second antenna selecting step, selecting to transmit an acknowledgment packet from only the second antenna of the second plurality of antennas at the second station after the first packet transmitting and receiving step, and

in response to the default antenna being selected in the default antenna selecting step, selecting to receive the acknowledgment packet with only the default antenna of the first plurality of antennas at the first station.

7. The method of claim 6, wherein the first packet has a training signal portion having a first duration, and said response packet has a training signal portion having a second duration which is less than the first duration.