System and Method for Dynamic Receive Diversity Allocation

• US 20090232100A1
• Filed: 03/14/2008
• Published: 09/17/2009
• Est. Priority Date: 03/14/2008
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Lantiq Deutschland GMBH (Intel Corporation)
• Inventors: Faber, Christian
• Granted Patent: US 8,085,734 B2
• Time in Patent Office: Days
• US Class Current: 370/334
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0817 with multiple receivers and antenna path selection
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff

Abstract

A system and method for dynamic receive diversity allocation. A communications device comprises a first physical layer (PHY) unit, a second PHY unit, a first signal path coupled to a first antenna and to the first PHY unit, a switchable signal path coupled to a second antenna and switchably coupled to the first PHY unit and the second PHY unit, and a switch control unit coupled to the second antenna. The switch control unit dynamically generates a control signal used to switchably couple the second antenna to either the first PHY unit or the second PHY unit. The second antenna may be used to provided a needed transmit or receive antenna or an extra antenna for use in increasing diversity. Switching antennas reduces the total number of antennas and support hardware, such as digital processing hardware, for wireless communications standards having a high ratio of idle to busy time.

Claims

1. A communications device, the communications device comprising:

a first physical layer (PHY) unit, the first PHY unit configured to encode, transmit, and receive data based on a first wireless communications specification;

a second PHY unit, the second PHY unit configured to encode, transmit, and receive data based on a second wireless communications specification;

a first signal path coupled to a first antenna and to the first PHY unit, the first signal path configured to perform processing on a signal in the first signal path;

a switchable signal path coupled to a second antenna and switchably coupled to the first PHY unit and to the second PHY unit, the switchable signal path configured to perform processing on a signal in the switchable signal path and to switchably couple the second antenna to either the first PHY unit or the second PHY unit based on a control signal; and

a switch control unit coupled to the second antenna, the switch control unit configured to generate the control signal to specify the coupling of the second antenna to either the first PHY unit or the second PHY unit.

2. The communications device of claim 1, wherein the first wireless communications specification and the second wireless communications specification comprise one wireless communications specification utilizing different frequency bands.

3. The communications device of claim 1, wherein the first signal path comprises a first analog hardware unit to perform analog signal processing on a signal in the first signal path.

4. The communications device of claim 3, wherein the first signal path further comprises a first digital hardware unit to perform digital signal processing on the signal in the first signal path.

5. The communications device of claim 1, wherein the switchable signal path comprises a multi-function analog hardware unit coupled to the second antenna, the multi-function analog hardware unit to perform analog signal processing on the signal in the switchable signal path according to either the first wireless communications specification or the second wireless communications specification.

6. The communications device of claim 5, wherein the switchable signal path is configured to additionally perform digital signal processing on the signal in the switchable signal path, and wherein the switchable signal path further comprises a multi-function digital hardware unit coupled to the multi-function analog hardware unit, the multi-function digital hardware unit to perform digital signal processing on the signal in the switchable signal path according to either the first wireless communications specification or the second wireless communications specification.

7. The communications device of claim 1, wherein the switchable signal path comprises:

a radio frequency (RF) switch coupled to the second antenna, the RF switch to switchably couple the switchable signal path to the second antenna based on the control signal;

a second analog hardware unit coupled to the RF switch, the second analog hardware unit to perform analog signal processing on the signal in the switchable signal path based on the first wireless communications specification;

a third analog hardware unit coupled to the RF switch, the third analog hardware unit to perform analog signal processing on the signal in the switchable signal path based on the second wireless communications specification;

a second digital hardware unit to perform digital signal processing on the signal in the switchable signal path according to either the first wireless communications specification or the second wireless communications specification;

a first switch coupled to the second digital hardware unit, to the second analog hardware unit, and to the third analog hardware unit, the first switch to switchably couple the second digital hardware unit to either the second analog hardware unit or the third analog hardware unit based on the control signal; and

a second switch coupled to the second digital hardware unit, the second switch to switchably couple the second digital hardware unit to either the first PHY unit or the second PHY unit based on the control signal.

8. The communications device of claim 7, wherein the second digital hardware unit comprises a Fourier unit configured to compute a time to frequency transform and a frequency to time transform of the signal in the switchable signal path.

9. The communications device of claim 7, wherein the second analog hardware unit and the third analog hardware unit each comprise:

a radio configured to send and receive radio frequency signals based on a respective wireless communications specification;

an analog to digital converter coupled to the radio, the analog to digital converter to convert an analog signal into a digital representation; and

a digital to analog converter coupled to the radio, the digital to analog converter to convert a digital signal into an analog representation.

10. The communications device of claim 1, further comprising a second signal path coupled to a third antenna and to the second PHY layer unit, the second signal path configured to perform processing on a signal in the second signal path.

11. The communications device of claim 1, wherein the communications device is configurable to support for the first wireless communications specification a transmitting and/or receiving according to at least one of the following techniques,

three independent spatial or time multiplexed data streams, or

two independent spatial or time multiplexed data streams with one antenna for diversity, or

one spatial or time multiplexed data stream with one antenna for diversity and one spatial or time multiplexed data stream, or

one spatial or time multiplexed data stream with two antennas for diversity, or

one spatial or time multiplexed data stream, or

two independent spatial or time multiplexed data streams,

and wherein the communication device is configurable to support for the second wireless communications specification a receiving and/or transmitting according to at least one of the following techniques,

two independent spatial or time multiplexed data streams, or

one spatial or time multiplexed data stream with one antenna for diversity, or

one spatial or time multiplexed data stream.

12. The communications device of claim 1, wherein the communication device is configured to dynamically switch the switchable signal path based on detected parameters related to an operation mode and/or a transmission environment during operation of the communication device.

13. A method for allocating an antenna in a communications device, the method comprising:

determining an operating mode of each physical layer (PHY) unit of a plurality of PHY units in the communications device;

selecting a PHY unit out of the plurality of PHY units to couple to a switchable antenna, to produce a selected PHY unit;

setting a value of a control signal based on the selected PHY unit; and

applying the control signal to switches in the communications device to couple the selected PHY unit to the switchable antenna.

14. The method of claim 13, further comprising prior to determining the operating mode, selecting a default PHY unit.

15. The method of claim 14, wherein selecting the default PHY unit is based on a series of criteria.

16. The method of claim 15, wherein the series of criteria includes one or more of the following:

quality of service restrictions, traffic priority, traffic type, received signal strength, expected performance, data modulation-coding scheme, and performance history.

17. The method of claim 14, wherein selecting the default PHY unit occurs when there is a change in a value of one or more of the criteria in the series of criteria.

18. The method of claim 14, further comprising, after selecting the default PHY unit, setting a value of the control signal based on the default PHY unit.

19. The method of claim 13, wherein a PHY unit may be in a LISTEN, RECEIVE, or TRANSMIT mode, and wherein determining the operating mode comprises tabulating an operating mode of each PHY unit.

20. The method of claim 13, wherein a PHY unit may be in a LISTEN, RECEIVE, or TRANSMIT mode, and wherein selecting the PHY unit comprises:

selecting a first PHY unit in response to a determining that,

the first PHY unit is in the RECEIVE mode and the first PHY unit requires the switchable antenna, or

the first PHY unit is in the TRANSMIT mode and the first PHY unit has been assigned the switchable antenna; and

selecting a second PHY unit in response to a determining that,

the first PHY unit is in the TRANSMIT mode and the first PHY unit has not been assigned the switchable antenna, or

the first PHY unit is in the RECEIVE mode and the first PHY unit does not require the switchable antenna, or

the first PHY unit is in the LISTEN mode.

21. The method of claim 13, further comprising after applying the control signal, repeating the selecting, the setting, and the applying in response to determining a change of operating mode for one or more PHY units.

22. The method of claim 13, wherein the selecting, the setting, and the applying are repeated each time a PHY unit transmits or receives.

23. A communications network comprising:

a first communications device;

a second communications device; and

an access point wirelessly coupled to the first communications device and to the second communications device, the access point having a switchable antenna assignable during transmissions and/or receptions of wirelessly transmitted information with the first communications device or the second communications device, wherein the assignment of the switchable antenna occurs on a transmission and/or reception basis, the access point configured to create a first wireless network with the first communications device using a first wireless communications standard and a second wireless network with the second communications device using a second wireless communications standard.

24. The communications network of claim 23, the access point comprising:

a first physical layer (PHY) unit to provide PHY processing for signals transmitted and/or received over the first wireless communications network;

a second PHY unit, the second PHY unit to provide PHY processing for signals transmitted and/or received over the second wireless communications network;

a switchable signal path coupled to a switchable antenna and switchably coupled to the first PHY unit and to the second PHY unit, the switchable signal path configured to perform analog processing on a signal in the switchable signal path and to switchably couple the switchable antenna to either the first PHY unit or the second PHY unit based on a control signal; and

a processor coupled to the first PHY unit, and to the second PHY unit, the processor configured to process information to be transmitted or information received and to control the switchable signal path, the processor comprising a switch control unit coupled to the switchable antenna, the switch control unit configured to generate the control signal to specify the coupling of the switchable antenna to either the first PHY unit or the second PHY unit.

25. The communications network of claim 24, the access point further comprising a first signal path coupled to a first antenna and to the first PHY unit, the first signal path configured to perform analog processing on a signal in the first signal path.