Blind Channel Identification Using Interpolation

In most of digital communication systems, low-pass filters are placed at a transmitter to confine the transmitting waveform to an allocated bandwidth and at a receiver to improve signal-to-noise power ratio. Consequently, if the received waveform is sampled with sufficiently fast rate, the resulting discrete-time signal is band-limited and exhibits a smooth waveform. The proposed method exploits this smooth property for estimating the channel impulse response, via an interpolation formula. One block of transmission is sufficient to estimate the channel, making the method suitable for mobile communication environment, in which the channel characteristic changes in a relatively short time span. No knowledge of input statistics or the autocorrelation of the received signals is required.