Efficient Use of Pseudo-Ternary Codes for Data Transmission

By using a simple code-converter for converting a binary data signal into a pseudo-ternary data signal it is possible to obtain a frequency spectrum containing several zeros. These zeros in the spectrum permit the transmission of different pilot signals, which can be used for bit synchronization and for phase reference of a demodulating carrier wave. In this way it is possible to apply single-sideband modulation for data transmission. Another possibility is the use of two channels by applying orthogonal modulation. In the present paper an orthogonal system is described which enables the transmission of 4800 bits per second. The clock signal is transmitted within the information band and the bandwidth occupied by the system ranges from about 700 to 3100 Hz.