We present matlab programming first experimental demonstration and characterization of matlab programming application of optical physical layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share matlab programming same link so one can enhance system throughput, while particular person OFDM frames can be recovered with digital signal processing at matlab programming destined node. To further enhance receiver sensitivity of spectrally effective guard band direct detection optical orthogonal frequency division multiplexing OFDM with twin single side band SSB modulation method, an optical IQ modulator IQM is employed to optimize optical provider to signal power ratio CSPR. The CSPRs for matlab programming guard band twin SSB OFDM signal generated through the use of dual drive Mach Zehnder modulator DD MZM and optical IQM are theoretically analyzed and supported by simulations. The top-rated CSPR for matlab programming two types of guard band twin SSB OFDM are identified. The simulations display that matlab programming error vector value EVM performance of matlab programming IQM enabled guard band twin SSB OFDM is superior by greater than 4 dB compared to that of matlab programming twin SSB OFDM enabled by DD MZM after 80 km single mode fiber SMF transmission.