摘要 |
<p>Messages are transmitted on pairs of frequencies that are orthogonal, that is the frequencies have no least common denominator. A message is transmitted on the first of the pair of frequencies (F1, F2) and, simultaneously, its compliment is transmitted on the second of said pair of frequencies (F1, F2). The message is then retransmitted on another pair of orthogonal frequencies. A processor is provided for collecting information on the data error rates at each receiver. This information is periodically transmitted to a central frequency controller which collects this error information and determines the error rates on the frequencies being used.</p> |