METHOD AND APPARATUS FOR IMPLEMENTING UPLINK TRANSMIT DIVERSITY IN A SWITCHED ANTENNA ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION SYSTEM

• US 20100322328A1
• Filed: 06/22/2009
• Published: 12/23/2010
• Est. Priority Date: 06/22/2009
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Wu, Wei, Schirmacher, Matthew S., Vook, Frederick W.
• Granted Patent: US 8,374,260 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04B 7/0404 the mobile station comprising multiple antennas, e.g. to provide uplink diversity
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0608 Antenna selection according to transmission parameters
• CPC Class Codes: H04B 7/0632 Channel quality parameters, e.g. channel quality indicator [CQI]
• CPC Class Codes: H04B 7/0634 Antenna weights or vector/matrix coefficients
• CPC Class Codes: H04L 27/2626 Arrangements specific to the transmitter only

Abstract

A method and a customer'"'"'s wireless communication device are provided that perform uplink transmit diversity in a switched antenna OFDM communication system. A switching of antennas used by the customer'"'"'s wireless communication device to transmit an uplink signal is restricted to switching time periods that comprise one or more of a transition gap immediately preceding a transmission of a channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but prior to the transmission of the channel quality-related uplink signal, which channel quality-related uplink signal may be used by a serving radio access network to update a channel response and antenna array weights associated with the customer'"'"'s wireless communication device. The customer'"'"'s wireless communication device then switches antennas used for uplink transmissions only during the switching time periods.

Claims

1. A method for providing uplink transmit diversity in a switched antenna Orthogonal Frequency Division Multiplexing communication system, the method comprising:

restricting a switching of antennas for use by a customer'"'"'s wireless communication device to transmit an uplink signal to switching time periods comprising one or more of a transition gap immediately preceding a transmission of a channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but prior to the transmission of the channel quality-related uplink signal, which channel quality-related uplink signal may be used by a serving radio access network to update a channel response and antenna array weights associated with the customer'"'"'s wireless communication device; and

switching, by the customer'"'"'s wireless communication device, from use of a first antenna of a plurality of antennas to use of a second antenna of the plurality of antennas for uplink transmissions only during the switching time periods.

2. The method of claim 1, wherein the channel quality-related uplink signal comprises one or more of a sounding signal and an indicator of a downlink signal quality measured by the customer'"'"'s wireless communication device.

3. The method of claim 1, further comprising:

selecting the first antenna for an uplink transmission;

subsequent to selecting the first antenna, transmitting, via the first antenna, a first channel quality-related uplink signal in a first uplink sub-frame; and

wherein switching comprises;

determining to transmit, via the second antenna, a second channel quality-related uplink signal during a second uplink sub-frame; and

switching to the second antenna during a one or more of a transition gap

immediately preceding a transmission of the second channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but

prior to the transmission of the channel quality-related uplink signal.

4. The method of claim 3, further comprising, subsequent to selecting the first antenna, transmitting uplink data bursts using only the first antenna until switching to the second antenna.

5. The method of claim 3, wherein a plurality of frames pass by, in time, between selecting the first antenna and switching to the second antenna.

6. The method of claim 3, further comprising:

receiving, by a radio access network, the first channel quality-related uplink signal;

estimating a channel response based on the first channel quality-related uplink signal; and

determining a set of antenna weights for downlink transmission based on the estimated channel response.

7. The method of claim 3, wherein the channel response is a first channel response and the set of antenna weights is a first set of antenna weights and wherein the method further comprises:

receiving, by the radio access network, the second channel quality-related uplink signal;

estimating a second channel response based on the second channel quality-related uplink signal; and

determining a second set of antenna weights for downlink transmission based on the estimated second channel response.

8. A customer'"'"'s wireless communication device that is capable of operating in an Orthogonal Frequency Division Multiplexing communication system and that comprises:

a plurality of antennas;

a switching device coupled to the plurality of antennas; and

a processor that is coupled to the switching device and that is configured to cause the switching device to switch from use of a first antenna of the plurality of antennas to use of a second antenna of the plurality of antennas for uplink transmissions only during the switching time periods, wherein the switching time periods are restricted to time periods comprising one or more of a transition gap immediately preceding a transmission of a channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but prior to the transmission of the channel quality-related uplink signal, which channel quality-related uplink signal may be used by a serving radio access network to update a channel response and antenna array weights associated with the customer'"'"'s wireless communication device.

9. The customer'"'"'s wireless communication device of claim 8, wherein the channel quality-related uplink signal comprises one or more of a sounding signal and an indicator of a downlink signal quality measured by the customer'"'"'s wireless communication device.

10. The customer'"'"'s wireless communication device of claim 8, wherein the processor further is configured to select the first antenna for an uplink transmission and subsequent to selecting the first antenna, transmit, via the first antenna, a first channel quality-related uplink signal in a first uplink sub-frame, and wherein the processor is configured to cause the switching device to switch from use of the first antenna to use of the second antenna by determining to transmit, via the second antenna, a second channel quality-related uplink signal during a second uplink sub-frame and switch to the second antenna during a one or more of a transition gap immediately preceding a transmission of the second channel quality-related uplink signal and a time period subsequent to the occurrence of the transition gap but prior to the transmission of the channel quality-related uplink signal.

11. The customer'"'"'s wireless communication device of claim 10, wherein the processor further is configured to, subsequent to selecting the first antenna, transmit uplink data bursts using only the first antenna until switching to the second antenna.

12. The customer'"'"'s wireless communication device of claim 10, wherein a plurality of frames pass by, in time, between selecting the first antenna and switching to the second antenna.

13. A wireless communication system comprising the customer'"'"'s wireless communication device of claim 10 and further comprising a network-based transceiver that is configured to receive the first channel quality-related uplink signal, estimate a channel response based on the first channel quality-related uplink signal, and determine a set of antenna weights for downlink transmission based on the estimated channel response.

14. A wireless communication system comprising the customer'"'"'s wireless communication device of claim 10, wherein the channel response is a first channel response, wherein the set of antenna weights is a first set of antenna weights, and wherein the system further comprises a network-based transceiver that is configured to receive the second channel quality-related uplink signal, estimate a second channel response based on the second channel quality-related uplink signal, and determine a second set of antenna weights for downlink transmission based on the estimated second channel response.