Estimation of time-varying channels is a common challenge for receiver architectures in wireless communications. Coherent receivers may require good knowledge of the channel impulse response for demodulation of the received symbols, after equalization of a dense multipath channel. However, very few methods for single-band transmission can offer a very fast estimation process that avoids using digital complex algorithms with matrix inversion or FFT. In this paper, we propose a new channel estimation scheme implemented in the continuous time domain, so as to feed a selective equalizer with information about reflected components delays and amplitudes. The principle relies on the evaluation of the spreading in time of the energy of multipath components and the approximation of their time of arrival. The robustness of our method gives a fast overview of the channel impulse response with an accurate and short-time estimation process. Analysis and simulations are performed to demonstrate the enhancement of the BER performance of a coherent receiver after equalization with the proposed method. ADC and equalizer implementation issues are also discussed.