For a IEEE conference paper, all fonts must be embedded in the pdf file.
The solution is print the non-embedded pdf file to the other pdf file.
One is CUPS-PDF, but the output file is strangely larger, and the version of the pdf is 1.3, which is lower than the standard.
The other driver comes from envince document reader, which is the default reader on UBUNTU. You can directly print the file as a pdf or ps file. The surprising thing is the size of the output file is small and all fonts are embedded.
Of course, the most simple one is use ps2pdf in the latex, use follow command:
"ps2pdf -dCompatibilityLevel=1.4 -dMAxSubsetPct=100 -dSubsetFonts=true -dEmbedAllFonts=true -sPAPERSIZE=letter -dPDFSETTINGS=/printer ".