Design of correlative non-overlapping ISI symbol transmission system over UHF/VHF vacant spread spectrums

Vacant spectrum is the space that remains unutilized during transmission of data. During transmission of signals most of the times in channels, bandwidth is having major attribute. It is important to make efficient use of bandwidth for any good signaling scheme. When there is transmission along any band limited channel, noise such as ISI arise. ISI leads to distortion in the transmitted signal and hence leads to reception of distorted signal. A technique called duobinary signaling also referred to as correlative coding has been used for establishing communication in vacant spread spectrums. Working of correlative coding is to introduce some controlled amount of ISI into the data stream rather than trying to eliminate it completely. A transmission system has been proposed in which correlative coding method has been used in order to reduce ISI and increase the efficiency in vacant spread spectrums.