Transmission power control is essential in systems of the third-generation
(3G) in order to optimize the bandwidth utilization, which is critical when
variable data rates are used. One remaining problem is oscillations in the
output powers, due to round-trip delays in the power control loops togethe
r with the power up-down command device. The oscillations are naturally qua
ntified using discrete time-describing functions, which are introduced and
applied, More importantly, time-delay compensation (TDC) is proposed to mit
igate the oscillations. When employing TDC, the power control algorithm exh
ibits greater stability, which is important from a network perspective. Sim
ulations illustrate the oscillations and the benefits of TDC, Moreover, the
fading tracking capability is improved, and thus, less fading margin is ne
eded. The results apply not only to wideband code division multiple access
(WCDMA), but to other direct-sequence (DS) CDMA systems power controlled in
a similar manner as well.