System and method for access terminal transition between a MIMO reverse-link mode and a non-MIMO reverse-link mode

An access terminal that is operable in a multiple input multiple output (MIMO) reverse-link mode and in a non-MIMO reverse-link mode, the access terminal comprising:

• a processor within the access terminal, wherein the access terminal is operable to transmit reverse-link communications via a first reverse-link and to receive forward-link communications via a forward-link;
• and
• a data storage device that contains first computer-readable program instructions and second computer-readable program instructions that are executable by the processor,
• wherein execution of the first program instructions causes the processor to determine reverse-link-activity indicators that indicate activity levels occurring on the first reverse-link monitored by the access terminal, and to determine whether the reverse-link-activity indicators indicate the activity levels on the first reverse-link exceeds a threshold level of activity or indicate the activity levels on the first reverse-link do not exceed the threshold level of activity,
• wherein, while the access terminal operates in the non-MIMO mode instead of the MIMO reverse-link mode, if the processor executes the first program instructions and determines that a first reverse-link-activity indicator indicates that an activity level occurring on the first reverse-link does not exceed the threshold level of activity, then the access terminal continues to operate in the non-MIMO reverse-link mode instead of the MIMO reverse-link mode,
• wherein, while the access terminal operates in the non-MIMO mode instead of the MIMO reverse-link mode, if the processor executes the first program instructions and determines that the first reverse-link-activity indicator indicates that the activity level on the first reverse-link monitored by the access terminal exceeds the threshold level of activity, then the processor executes the second program instructions, and
• wherein execution of the second program instructions causes the access terminal to transition from operating in the non-MIMO reverse-link mode to the MIMO reverse-link mode.

At an access terminal operable in a multiple input multiple output (MIMO) reverse-link mode and in a non-MIMO reverse-link mode, a method comprising:

• determining, by the access terminal while the access terminal operates in the non-MIMO reverse-link mode via a first reverse-link instead of the MIMO reverse-link mode, (i) a reverse-link-activity indicator that indicates an activity level occurring on a second reverse-link that is monitored by the access terminal, and (ii) a first determination indicating the activity level on the second reverse-link exceeds a threshold level of activity or indicating the activity level on the second reverse-link does not exceed the threshold level of activity, wherein the access terminal is operable to transmit reverse-link communications via the first reverse-link and to receive forward-link communications via a forward-link;
• continuing, by the access terminal, operation of the access terminal in the non-MIMO reverse-link mode via the first reverse-link instead of the MIMO reverse-link mode if the first determination indicates the activity level on the second reverse-link does not exceed the threshold level of activity;
• and
• transitioning, by the access terminal, operation of the access terminal from the non-MIMO reverse-link mode via the first reverse-link instead of the MIMO reverse-link mode to the MIMO reverse-link mode via the first reverse-link instead of the non-MIMO reverse-link mode on the first reverse-link if the first determination indicates the activity level on the second reverse-link exceeds the threshold level of activity.