A method and apparatus for channel estimation in a rake receiver of a CDMA communication system operates with a finite-impulse-response channel estimation filter with L taps and having a fixed delay. A pilot sequence of a received sequence of data from a channel of the communication system on the rake receiver is input. A quality of the channel of the communication system is determined using noise or Doppler measurements. These measurements are used in adjusting a bandwidth of the filter to accommodate the channel quality while keeping the fixed delay, which minimizes the delay buffer size. The filter is then used to operate on the received sequence of data to provide coherent modulation.