This article proposes a high-speed framed-pulsewidth modulation (FPWM) transceiver that applies a time-domain modulation scheme for increased spectrum efficiency. The achieved coding gain is 75%, indicating that the minimum pulsewidth is increased by 1.75 times compared to an NRZ scheme with an identical data rate. Such bandwidth reduction renders dispersion tolerance both in copper and optical channels. The encoder and decoder employ successive approximation (SA) and weighted sum (WS) algorithms for power-and-area efficiency. The FPWM demonstrates an 8-dB SNR gain over NRZ at 15-km single-mode fiber (SMF) transmission while maintaining identical back-to-back performance. The FPWM scheme shows 6-dB higher receiver sensitivity at a bit error rate (BER) of 2e-5 than the PAM-4 signaling in 26-Gb/s back-to-back transmission and achieves 4-dB SNR gain at 20-km transmission. The test chip is fabricated in a 28-nm CMOS process and packaged in a flip-chip chip scale package (FCCSP). The test chip occupies $2.2\times2.0$ mm, including bidirectional two lanes and two phase-locked loops (PLLs), while it consumes 262 mW per lane from a 0.9-V supply. The measured Tx random jitter is 265 fs $_{\mathrm {rms}}$ .

中文翻译：

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用于长距离光链路的 26 Gb/s 框架脉宽调制收发器


本文提出了一种高速帧脉宽调制 (FPWM) 收发器，该收发器应用时域调制方案来提高频谱效率。实现的编码增益为75%，表明与相同数据速率的NRZ方案相比，最小脉冲宽度增加了1.75倍。这种带宽的减少使得铜通道和光通道中的色散容限都得到改善。编码器和解码器采用逐次逼近 (SA) 和加权和 (WS) 算法来提高功耗和面积效率。 FPWM 在 15 公里单模光纤 (SMF) 传输中表现出比 NRZ 多 8dB 的 SNR 增益，同时保持相同的背靠背性能。 FPWM 方案在 2e-5 的误码率 (BER) 下显示出比 26 Gb/s 背靠背传输中的 PAM-4 信令高 6 dB 的接收器灵敏度，并在 20 比特误码率 (BER) 下实现了 4 dB SNR 增益。公里传输。测试芯片采用 28 nm CMOS 工艺制造，并采用倒装芯片尺寸封装 (FCCSP) 封装。该测试芯片占用 $2.2\times2.0$ mm，包括双向两个通道和两个锁相环 (PLL)，而每个通道的功耗为 262 mW，电源电压为 0.9V。测得的 Tx 随机抖动为 265 fs $_{\mathrm {rms}}$ 。