Patent ID: 7205859

Claim:
An apparatus for processing a communication signal comprising a continuous phase modulated waveform containing information symbols of an M-ary alphabet comprising: an analog to digital converter; an interpolator for reconstructing the waveform; and, a demodulator for extracting the information symbols from the reconstructed waveform; wherein the ADC operates at a sample frequency at or less than the symbol rate of the communication signal, wherein the waveform is: where Φ(t,α) is a continuous function, expressed as: s ⁡ ( t ) = 2 ⁢ E s T s ⁢ cos ⁡ ( 2 ⁢ π ⁢ ⁢ f o ⁢ t + Φ ⁡ ( t , α ) + ϕ 0 ) Φ ⁡ ( t , α ) = 2 ⁢ π ⁢ ⁢ h ⁢ ∑ k = - ∞ ∞ ⁢ ⁢ α k ⁢ q ⁡ ( t - k ⁢ ⁢ T s ) ⁢ where h is the modulation index, q(t) is the phase pulse shape and α k are the information symbols. T s is the symbol rate.