Diversity transceiver for a wireless local area network

• US 7,636,344 B2
• Filed: 05/31/2006
• Issued: 12/22/2009
• Est. Priority Date: 03/19/2001
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Weste, Neil, O'Sullivan, John
• Primary Examiner(s): Duong; Frank
• Application Number:
  US11/421,204
• Publication Number:
  US 20070049348A1
• Time in Patent Office: 1,301 Days
• Field of Search: None
• US Class Current: 370/338
• CPC Class Codes: H04B 7/0814 based on current reception conditions, e.g. switching to different antenna when signal level is below threshold
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only
• CPC Class Codes: H04L 27/2647 Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A wireless local area network system comprises a 5.0+ GHz radio transceiver with two receiving antennas and one transmitting antenna. A transmitter power amplifier output is connected to the transmitting antenna through a 6-8 pole filter to control spurious signal output. Each receiving antenna is fitted with its own low-noise amplifier followed by a simple bandpass filter. Each bandpass filter feeds a diversity switch with a single output to a single receiver. The radio system constitutes a physical-layer (PHY) part of a wireless local-area network.

Claims

1. A method of operating a wireless station of a wireless network, the wireless station including a receive path with a first stage of radio frequency amplification, the method comprising the steps of:

separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

providing at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein a transmit/receive switch and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification.

2. A method as recited in claim 1, wherein the providing provides at least two receiver antennas and at least one transmitter antenna, such that the wireless station includes at least two receiver antennas and at least one transmitter antenna and is configured to operate with diversity for reception, the method further comprising receiving via one of the receiver antennas selected according to radio signal quality.

3. A method as recited in claim 2, further comprising switching to a first low noise receiving amplifier coupled to the one selected receiving antenna from a second low noise receiving amplifier coupled to another one of the receiver antennas.

4. A method as recited in claim 1, wherein the providing provides at least two transmitter antennas and at least two receiver antenna, such that the wireless station includes at least two receiver antennas and at least two transmitter antennas and is configured to operate with diversity for transmission by selecting one of the transmitter antennas according to a response to the wireless station transmitting a test transmission and to operate with diversity for reception by selecting one of the receiver antennas according to radio signal quality.

5. A method as recited in claim 1, wherein the transmission and reception signals are OFDM signals.

6. A method as recited in claim 1, wherein the providing provides at least two transmitter antennas and at least one receiver antenna, such that the wireless station includes at least two transmitter antennas and at least one receiver antenna and is configured to operate with diversity for transmission, the method further comprising transmitting via one of the transmitter antennas selected according to a response to the wireless station transmitting a test transmission.

7. A method as recited in claim 6, further comprising switching power to a first power amplifier coupled to the one selected transmitter antenna from a second power amplifier coupled to another one of the transmitter antennas.

17. A means for increasing the available radio signal as recited in claim 5, wherein the at least two transmitter antennas and/or at least two receiver antennas include at least two receiver antennas and at least one transmitter antenna, such that the means for increasing the available radio signal can operate with diversity for reception, the means for increasing the available radio signal further comprising

means for selecting one of the receiver antennas for receiving according to radio signal quality;

and

means for receiving via the one receiver antenna selected by the means for selecting.

18. A means for increasing the available radio signal as recited in claim 17, wherein the means for selecting includes means for switching to a first low noise receiving amplifier coupled to the one selected receiving antenna from a second low noise receiving amplifier coupled to another one of the receiver antennas.

8. A method of operating a wireless station of a wireless network, the wireless station including a receive path with a first stage of radio frequency amplification, the method comprising the steps of:

separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

providing at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a multi-pole bandpass filter for said radio transmission signals and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification.

9. A method operating a wireless station of a wireless network, the wireless station including a receive path with a first stage of radio frequency amplification, the method comprising the steps of:

separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

providing at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a first stage of radio-frequency amplification is placed in a path after an antenna receiving wireless local area network transmission signals and before a simple bandpass filter for said radio reception signals and its concomitant signal insertion loss.

10. A method of operating a wireless station of a wireless network, the wireless station including a receive path with a first stage of radio frequency amplification, the method comprising the steps of:

separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

providing at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a transmit/receive switch and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals an a first stage of radio-frequency amplification;

wherein, a multi-pole bandpass filter for said radio transmission signals and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification; and

wherein, a first stage of radio-frequency amplification is placed in a path after an antenna receiving wireless local area network transmission signals and before a simple bandpass filter for said radio reception signals and its concomitant signal insertion loss.

11. A means for increasing the available radio signal in a wireless local area network, comprising:

means for separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

means for multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a multi-pole bandpass filter for said radio transmission signals and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification.

12. A means for increasing the available radio signal in a wireless local area network, comprising:

means for separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

means for multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a first stage of radio-frequency amplification is placed in a path after an antenna receiving wireless local area network transmission signals and before a simple bandpass filter for said radio reception signals and its concomitant signal insertion loss.

13. A means for increasing the available radio signal in a wireless local area network, the means for increasing the available radio signal comprising:

means for separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

means for multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein, a transmit/receive switch and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals an a first stage of radio-frequency amplification;

wherein, a multi-pole bandpass filter for said radio transmission signals and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification; and

wherein, a first stage of radio-frequency amplification is placed in a path after an antenna receiving wireless local area network transmission signals and before a simple bandpass filter for said radio reception signals and its concomitant signal insertion loss.

14. A means for increasing the available radio signal in a wireles local area network, comprising:

means for separating radio transmission signals for transmission and reception signals received into corresponding one or more transmitter antennas and signals from corresponding one or more receiving antennas;

at least three antennas including at least two transmitter antennas and at least one receive antenna, or including at least two receiver antennas and at least one transmit antenna, such there is transmit and/or receive diversity without a transmit/receive switch; and

means for multiplexing between said at least two receive antennas with a receiver diversity switch and/or between said at least two transmit antennas with a transmitter diversity switch;

wherein a transmit/receive switch and its concomitant signal insertion loss is eliminated from a path between an antenna receiving wireless local area network transmission signals and a first stage of radio-frequency amplification.

15. A means for increasing the available radio signal as recited in claim 14, wherein the at least two transmitter antennas and/or at least two receiver antennas include at least two transmitter antennas and at least one receiver antenna, such that the means for increasing the available radio signal can operate with diversity for transmission, the means for increasing the available radio signal further comprising,

means for selecting one of the transmitter antennas for transmission according to a response to the means for increasing the available radio signal'"'"'s transmitting a test transmission;

and

means for transmitting via the one transmitter antenna selected by the means for selecting.

16. A means for increasing the available radio signal as recited in claim 15, further comprising means for switching power to a first power amplifier coupled to the one transmitter antenna selected by the means for selecting from a second power amplifier coupled to another one of the transmitter antennas.

19. A means for increasing the available radio signal as recited in claim 14, wherein the at least two transmitter antennas and/or at least two receiver antennas include at least two transmitter antennas and at least two receiver antennas, such that the means for increasing the available radio signal can operate with diversity for transmission and diversity for reception, the means for increasing the available radio signal farther comprising,

means for selecting one of the transmitter antennas for transmission according to a response to the means for increasing the available radio signal'"'"'s transmitting a test transmission;

means for transmitting via the one transmitter antenna selected by the means for selecting one of the transmitter antennas;

means for selecting one of the receiver antennas for receiving according to radio signal quality; and

means for receiving via the one receiver antenna selected by the means for selecting one of the receiver antennas.

20. A means for increasing the available radio signal as recited in claim 14, wherein the transmission and reception signals are OFDM signals.