Spectrally efficient communication is studied for short-reach fiber-optic links with chromatic dispersion (CD) and receivers that employ direction-detection and oversampling. Achievable rates and symbol error probabilities are computed by using auxiliary channels that account for memory in the sampled symbol strings. Real-alphabet bipolar and complex-alphabet symmetric modulations are shown to achieve significant energy gains over classic intensity modulation. Moreover, frequency-domain raised-cosine (FD-RC) pulses outperform time-domain RC (TD-RC) pulses in terms of spectral efficiency for two scenarios. First, if one shares the spectrum with other users then inter-channel interference significantly reduces the TD-RC rates. Second, if there is a transmit filter to avoid interference then the detection complexity of FD-RC and TD-RC pulses is similar but FD-RC achieves higher rates.
翻译:光谱高效通信用于研究与色谱分散(CD)和接收器的短距离光纤连接,这些光纤连接使用方向检测和过度取样。可用辅助渠道计算出率和符号误差概率,这些渠道在样本符号字符串中考虑到内存情况。双极和复合α对称调制式显示,在典型的强度调制制器中取得显著的能量增益。此外,频率-多面加热(FD-RC)脉冲在光谱效率方面高于RC(TD-RC)时空脉冲。首先,如果与其他用户分享频谱,则频道间干扰会显著降低TD-RC的速率。第二,如果有传输过滤器,则发现FD-RC和TD-RC脉冲的复杂性是相似的,但FD-RC的速率更高。