Low frequency suppression of baseband coded sequences
Louis Botha, Hendrik Christoffel Ferreira · 2002
Two classes of sequences with favourable low frequency spectral suppression are considered. They are sequences with higher order zeroes at zero frequency and sequences which comply to restrictions on the time between crossings of the average RDS value. It is shown how these sequences can be used to transmit a conventional analog speech channel on the same channel as a digital signal, but totally independent from it. An optimization problem regarding the choice of a code sequence for a specific application is then considered, and finally a new code with suppressed low frequencies is presented.>