Demonstration of Delay Distortion Correction by Time-Reversal Techniques

Experiments relating to methods of correcting delay distortion by time-reversal have been made utilizing a slow-speed picture transmission system. The improvements in picture quality by phase correction of a 3 KC telephone loop 30.4 miles long and a 5 KC loop from Murray Hill, N. J., to Los Angeles, Calif., and back are demonstrated. The total distance that the signal was transmitted over the 5 KC loop was 16,600 miles and there were 16 type L carrier links involved. By way of an introduction, the improvement in the impulse response of networks and transmission circuits is discussed.