400-Gb/s Single-Sideband Direct Detection Over 7-Core Fiber With SSBI Cancellation

In this letter, a signal-to-signal beating interference (SSBI) cancellation technique is proposed in direct detection transmission system based on balanced photodiodes. We use a pilot-supported single-sideband direct detection scheme to transmit up to 400-Gb/s signal in three branches through a 10-km 7-core fiber. Using the manner of transmitting the signal in one core and the combination of signal and pilot in another core, the SSBI terms can be efficiently mitigated in both 100-Gb/s and 400-Gb/s direct detection optical orthogonal frequency division multiplexing transmission systems. Compared to the conventional pilot-supported direct detection scheme, no guard band is required based on our proposed SSBI elimination technique. The efficiency of the receiver's bandwidth is significantly enhanced.