INCREASING CHANNEL CAPACITY WITHOUT NEEDING TO REDUCE SIGNAL TO NOISE MARGIN DUE TO INTER-SYMBOL INTERFERENCE (ISI) BY USING THREE STATES +1, -1 AND NO

摘要

Basic idea is that in addition to sending +1 and -1 a third state is sent. This third state is a lack of any transmission whatsoever. Suggests sending frequency 0 for symbol 0, frequency 1 for symbol 1, frequency 2 for symbol 2, frequency 0 & frequency 1 for symbol 3 etc. Also suggests using 2 frequencies and phase modulating each. Frequency 1 has 2 possible phase states and frequency 2 has 2 possible phase states, therefore 4 bits can be coded. If send only frequency 2 with its two phase states, this enables us to send two more bits. If send neither frequency 1, nor frequency 2 this indicates 1 other bit state. Therefore 8 bits can be coded.