Bit timing transmission and spectral shaping of digital signals

For bit timing or bit synchronisation of non-return-to-zero (NRZ) and multi-level random data, conventional non-linear processing of the signal is usually performed at the receiver. A novel method for bit timing transmission, in which the non-linear processing is performed at the transmitter, is presented. The transmitted signal then becomes a modified NRZ or multi-level signal, having asymmetric and finite rise and fall times and faster spectral roll-off than conventional NRZ signals. The received signal can then be processed by linear methods to recover the timing data.