公开(公告)号：US5351148A

公开(公告)日：1994-09-27

申请号：US67217

申请日：1993-05-26

申请人： Kazuki Maeda ,  Naoki Ishiyama ,  Hiroaki Nakata

发明人： Kazuki Maeda ,  Naoki Ishiyama ,  Hiroaki Nakata

IPC分类号： H04B10/516 ,  H04B10/2507 ,  H04B10/54 ,  H04B10/556 ,  H04B10/61 ,  H04B14/00 ,  H04J14/02 ,  H04L5/06 ,  H04N7/22

CPC分类号： H04N7/22 ,  H04B10/504 ,  H04B10/5053 ,  H04B10/541 ,  H04B10/58 ,  H04J14/0298 ,  H04L5/06

摘要： An optical transmission system provides digital signals which have added bits for error correction by an encoder which are converted into 16-QAM signals with a predetermined carrier frequency by a modulator, and then frequency division muitiplexed with an AM signal so as to be inputted to an optical-electric converter. When the total sum of the light modulation indices of signals to be transmitted is over 1, a light modulation index of an M-QAM signal is set by calculating the light modulation index that marks the onset of diverging from the error rate given by a ratio between receiver noise power and the M-QAM signal power while considering a light modulation index corresponding to a usable transmission margin. The multiplexed signals are transmitted via optical fiber and converted into electric signals by a photo receiver, demodulated by a demodulator, and then outputted after having their errors corrected by an error corrector.

摘要翻译： 光传输系统提供数字信号，该信号已经由编码器添加了用于纠错的比特，其通过调制器被转换成具有预定载波频率的16-QAM信号，然后与AM信号进行频分复用以被输入到 光电转换器。 当要发送的信号的光调制指数的总和超过1时，通过计算从由比率给出的误码率来标记发散开始的光调制指数来设置M-QAM信号的光调制指数 在接收机噪声功率和M-QAM信号功率之间考虑与可用传输余量对应的光调制指数。 多路复用信号通过光纤传输并通过光接收机转换成电信号，由解调器解调，然后在由误差校正器校正其误差之后输出。