To solve the problem of quality deterioration of optical orthogonal frequency di vision multiplexing (OOFDM) signal after lo ng distance transmission due to the passive effects of chromatic dispersion (CD) and polarization mode dispersion (PMD) of f iber, a novel remote coherent optical orthogonal frequency division multiplexing (CO-OFDM) access system using optical phase div ersity receiver is proposed,theoretically analyzed,and demonstrated by simulation.In this scheme,the dispersion compens ation fiber (DCF) or the dispersion compensating module (DCM) for compensating chromatic dispersion negative effects from optical fiber channel has not been used,since CO-OFDM optical signal transmission can effectively resist the negative effect s caused by chromatic dispersion (CD) and polarization mode dispersion (PMD).Simulation results show that after transmiss ion of optical OFDM signal at 10Gbit/s over 320km SMF-28,the range of phase jitter of received electrical signal by using phase estimation is more limited.A comparison is made between this scheme and the phase modulation optical OFDM method based on s elf carrier extraction,and results show that by using optical phase diversity re ceiver and phase estimation simultaneously,b etter receiver performance can be obtained,the receiver constellation of OFDM signal is more compact,the EVM performance is be tter and the quality of received signal is higher. Hence,this scheme has potential application value for CO-OFDM signal remote a ccess system.