A　photonics-assisted　frequency　conversion　and　self-interference　cancellation　approach　is　proposed　and　experimentally　demonstrated　for　in-band　full-duplex　(IBFD)　communication.　Carrier　suppressed　single　sidebands　(CS-SSB)　of　the　intermediate　frequency　(IF)　signal　and　the　local　oscillator　(LO)　signal　are　simultaneously　obtained　through　the　X-DPMZM　in　a　dual-polarization　dual-parallel　Mach-Zehnder　(DP-DPMZM)　modulator.　A　transmit　signal　with　high　purity　is　produced,　and　a　shared　LO　optical　sideband　is　also　provided　for　the　subsequent　downconversion.　The　carrier　suppressed　double　sideband　(CS-DSB)　modulation　for　the　signal　of　interest　(SOI)　is　achieved　via　the　Y-DPMZM.　The　self-interference　signal　is　suppressed　by　adjusting　the　bias　voltage　of　its　main　MZM.　An　optical　bandpass　filter　(OBPF)　is　combined　to　realize　frequency　downconversion.　The　experimental　results　show　that　the　spurious-free　dynamic　range　(SFDR3)　is　102.6　dB/Hz(2/3)　for　frequency　upconversion,　a　cancellation　depth　of　more　than　50　dB　for　single-frequency　self-interference　cancellation　(SIC),　and　more　than　22　dB　for　wideband　SIC.　The　proposed　link　has　superiority　in　multifunctionality,　including　in-band　transmission,　reception,　and　self-interference　cancellation,　with　a　shared　LO.