| 摘要 |
<p>PURPOSE:To prevent a hard of hearing state due to the deterioration in articulation caused by a change in a decoded voice occurred when digital cipher communication is applied to the frequency hopping communication system by implementing transmission reception with specific constitution. CONSTITUTION:In the frequency hopping communication system in which a voice signal is digital-coded to a prescribed frame length, a carrier frequency is hopped at a longer period than the length of the frame so as to implement communication, a sender side uses a timing control means to switch the hopping frequency near the middle of the frame for sending the frame and a receiver side decodes a code of a preceding frame as to the frame having the frequency changeover. That is, preceding frames F2, F6 are outputted in the case of frames F'3, F'6 having a changeover at a demodulated digital code (g) to obtain a code (i). Then a voice signal (j) is decoded, a sense of displeasure in a listening sense is prevented and the articulation is improved.</p> |
