Electronically configurable transmit and receive paths for FDD wireless communication devices

• US 7,587,177 B1
• Filed: 12/12/2005
• Issued: 09/08/2009
• Est. Priority Date: 12/12/2005
• Status: Active Grant

• Current Assignee: Exalt Wireless Incorporated
• Original Assignee: Exalt, Inc.
• Inventors: Kwong, Kelvin H.
• Primary Examiner(s): Anderson; Matthew D
• Assistant Examiner(s): GONZALES, APRIL GUZMAN
• Application Number:
  US11/301,810
• Time in Patent Office: 1,366 Days
• Field of Search: 455/552.1, 455/553.1, 455/82, 455/78, 455/575.7, 455/101, 455/115.1, 455/132, 455/140, 455/575.9, 455/129, 455/269, 343/702, 343/700
• US Class Current: 455/78
• CPC Class Codes: H04B 1/0057 using diplexing or multiplexing filters for selecting the desired band

Abstract

Methods and systems are provided for allowing an FDD radio to be configured to operate in Rx-high/Tx-low or Rx-low/Tx-high modes of operation. In accordance with one aspect, this is achieved in an FDD radio configuration that includes multiple switches, multiple Rx electronics, and multiple Tx electronics, allowing a diplexing filter to have selectively coupled to its high and low terminals desired Tx or Rx paths, such as to allow the radio to operate in one or another mode.

Claims

1. An apparatus comprising:

a diplexer, having a high terminal and a low terminal;

a high receive path;

a high transmit path;

a low receive path;

a low transmit path;

a first diplexer switch, coupled to the high terminal of the diplexer and further coupled to the high receive path and the high transmit path, the first diplexer switch to selectively couple either the high receive path or the high transmit path to the high terminal of the diplexer;

a second diplexer switch, coupled to the low terminal of the diplexer and further coupled to the low receive path and the low transmit path, the second diplexer switch to selectively couple either the low receive path or the low transmit path to the low terminal of the diplexer;

a modem having a receive port and a transmit port;

a transmit switch, coupled to the transmit port of the modem and further coupled the high transmit path and the low transmit path, the transmit switch to selectively couple either the high transmit path or the low transmit path to the transmit port of the modem; and

a receive switch, coupled to the receive port of the modem and further coupled to the high receive path and the low receive path, the receive switch to selectively couple either the high receive path or the low receive path to the receive port of the modem.

2. The apparatus of claim 1, wherein the receive and transmit switches are configured to operate at lower frequencies relative to the first and second diplexer switches.

3. The apparatus of claim 1, wherein the receive and transmit switches are configured to operate at intermediate frequency (IF) and the first and second diplexer switches are configured to operate at carrier frequency (RF).

4. The apparatus of claim 3, wherein the RF frequency is one of 2.4 Gflz, 5.8 GI-lz and 11 Gflz.

5. The apparatus of claim 1, further comprising a modulator having an input coupled to the transmit port of the modem and an output coupled to the transmit switch.

6. The apparatus of claim 5, further comprising a demodulator having an output coupled to the receive port of the modem and an input coupled to the receive switch.

7. A wireless communication device that allows full duplex communication comprising:

a diplexing filter comprising high and low terminals;

a first transmit path;

a second transmit path;

a first receive path;

a second receive path;

a plurality of switches, controlled by software, to selectively couple one of the first and second receive paths to the high or low terminal of the diplexing filter and to selectively couple one of the first and second transmit paths to the other terminal of the diplexing filter, thereby allowing the device to operate in a first mode for allowing Tx-high and Rx-low or in a second mode for allowing Tx-low and Rx-high; and

processing circuitry that;

(1) determines whether wireless communications received at the wireless communication device from another device are in (a) Tx-low/Rx-high mode or (b) Tx-high/Rx-low mode, (2) automatically sets the plurality of switches to a first configuration that causes the wireless communication device to be in Tx-low/Rx-high mode in response to determining that the received communications are in Tx-high/Rx-low mode, and (3) automatically sets the plurality of switches to a second configuration that causes the wireless communication device to be in Tx-low/Rx-high mode in response to determining that the received communications are in Tx-high/Rx-low mode.

8. The device of claim 7, wherein at least one of the plurality of switches comprises an electronic single pole, double throw (SPDT) switch.

9. The device of claim 8, wherein the plurality of switches includes a set of four SPDT switches.

10. The device of claim 9, wherein at least one of the set of SPDT switches operates at a different frequency relative to at least another one of the set of SPDT switches.

11. The device of claim 10, further comprising a graphical user interface (GUI) for allowing a user to select one of the first and second modes.

12. The device of claim 10, further comprising a mechanical switch for allowing selection of the first and second modes.

13. A method comprising:

receiving, at a first radio device that is in Tx-low/Rx-high mode, transmissions from a second radio device that also is in Tx-low/Rx-high mode;

determining, in response to the receiving, that the second radio device is also in Tx-low/Rx-high mode;

in response to determining that the second radio device is also in Tx-low/Rx-high mode, automatically modifying a set of switches to change configurable paths within the first radio device;

wherein automatically modifying the set of switches to change configurable paths within the first radio device causes the first radio device to leave Tx-low/Rx-high mode and enter Tx-high/Rx-low mode instead.

14. The method of claim 13, wherein the determining and the modifying steps are performed by processing circuitry within the first radio device rather than by a human being.