A Standalone Receiver With Multiple Access Interference Rejection, Clock and Data Recovery, and FEC for 2-D OCDMA

We demonstrate a standalone (no global clock) receiver for two-dimensional wavelength-time optical code-division multiple-access. The receiver provides the following functions: quantization (to eliminate multiple access interference), clock and data recovery, return-to-zero to nonreturn-to-zero conversion (for optical code-division multiple-access compatibility with digital logic), framing (for byte synchronization), and forward-error correction (FEC) using a (255, 239) Reed-Solomon decoder. The receiver more than doubles the number of supported users at a bit-error rate <10^-10. The receiver supports an information rate of 156.25 Mb/s. We performed the measurements at a bit rate of 167.4 Mb/s and a chip rate of 1.339 Gb/s (eight chips per bit) to account for FEC overhead