Apparatus and methods efficiently estimate signal-to-noise ratios of a received signal irrespective of intentional adjustments to transmitting power due to fluctuating data rates. For example, in one embodiment, the variation in power due to the change in data rate is decoupled from environmental sources for variations in power. In one embodiment, the signal to noise ratio is adjusted for the data rate. In another embodiment, another signal is used as a reference for the signal to noise computation. This advantageously permits a system to efficiently and accurately control power in a power control loop for efficient use of spectral bandwidth and for relatively good grade of service (GoS).