A clock recovery technique based on spectral restoration

A clock recovery technique suitable for several families of modulation-demodulation methods is presented. The modulation method should exhibit a timing relationship among the carrier frequency and the symbol rate. Two major examples are phase shift keying (m-PSK) and quadrature amplitude modulation (m-QAM) families. The key feature of the proposed technique when applied to the above modulation formats is the relative ease of synchronization and/or timing recovery. The method is applicable to non return to zero (NRZ) data formats, as well. It is based on the modification of conventional, off-the-self, phase locked loop (PLL) devices.