A rate feedback and adaptation scheme or system uses a rate of rate feedback
asymmetrical
with the rate of data rate adaptation. In particular, the rate adaptation system
provides a rate of rate feedback slower than the rate of rate adaptation. Thus,
by allowing the base station to change the data rate more frequently than the individual
wireless units reports the rate information, the rate adaptation system can provide
improved flexibility and more efficient use of wireless resources while reducing
the processing and transmission overhead required to report the rate information.
For example, every 3 slots, a wireless unit can calculate and report a rate for
the wireless unit to use on a shared channel to send data. The base station receives
the rates from the wireless units seeking to send data over the shared channel
and selects a wireless unit to use the shared channel. If the base station can
adapt the data rate every slot, the base station can adapt the data rate in accordance
with a rate reported by another wireless unit, thereby improving system performance.
Because of the small slot duration (for example, 0.67 microseconds), the relatively
reduced rate of reporting should not adversely effect system performance since
it is highly unlikely that the achievable data rate will change over a period of
a slot under most operating conditions.