A coder for halving the bandwidth of signals
A.R. Billings · The proceedings of the Institution of Electrical Engineers. Part B, Radio and electronic engineering, including communication engineering · 1958
It is shown that it is possible to code a continuous message of finite bandwidth into a continuous signal of smaller bandwidth, provided that sufficient signal power is available. A possible practical system capable of performing this coding is described and it is shown that the exchange of bandwidth for power occurs in the same manner as for Shannon's ideal system.