Techniques for estimating thermal noise and rise-over-thermal (RoT) in a communication system are described. In an aspect, thermal noise in a sideband may be measured and used to estimate thermal noise in a signal band. In one design, received power in the sideband may be measured, e.g., by computing total power of FFT transform coefficients within the sideband. Thermal noise may be estimated based on (e.g., by filtering) the measured received power in the sideband. Received power in the signal band may also be measured. Total received power may be estimated based on (e.g., by filtering) the measured received power in the signal band. RoT may then be estimated based on the estimated thermal noise and the estimated total received power. The estimated RoT may be used to estimate an available load for a cell, which may be used to admit and/or schedule users in the cell.