Method and apparatus for synchronizing WLAN in a multi-mode radio system

A method of controlling a multi-mode wireless communication device, the method comprising:

• determining a time that a first sub-system is active, the first sub-system configured to enable the multi-mode wireless communication device to communicate with a first wireless communication system;
• generating an energy signal in a baseband portion of the first sub-system during at least a portion of the time that the first sub-system is active, the energy signal configured to exceed a predetermined Clear Channel Assessment (CCA) threshold;
• and
• coupling the energy signal to a receive signal path of a baseband portion of a Wireless Local Area Network (WLAN) sub-system within the multi-mode wireless communication device to control the multi-mode wireless communication device, the WLAN sub-system implementing collision avoidance based on the CCA threshold.

A multi-mode wireless communication apparatus, the apparatus comprising:

• a radio portion;
• a Wireless Local Area Network (WLAN) baseband portion coupled to the radio portion and configured to determine a transmit channel availability using a Clear Channel Assessment (CCA) mechanism;
• and
• a sub-system baseband portion coupled to the radio portion and configured to support communications over a wireless communication system, the sub-system baseband portion distinct from the WLAN baseband portion, and configured to determine a time that communications with the wireless communication system is active, generate an energy signal during at least a portion of the time that communications with the wireless communication system is active, and couple the energy signal to a receive input of the WLAN baseband portion.

A multi-mode wireless communication apparatus, the apparatus comprising:

• a radio portion configured to generate an energy signal based on an operating state of the radio portion and output the energy signal at an energy signal output;
• a Wireless Local Area Network (WLAN) baseband portion having a receive signal input coupled to the radio portion and energy signal output, and configured to support communications with a WLAN communication system and to determine a transmit channel availability using a Clear Channel Assessment (CCA) mechanism;
• and
• a sub-system baseband portion coupled to the radio portion and configured to support communications with a wireless communication system distinct from the WLAN communication system.