类别：
- CDTV
- CDVT
- CEIR
- CELP
- CEPT
- CFNRc
- CFNRy
- CG
- CGF
- CGM
- CHESS
- Chirp
- CI
- CIR
- CIRC
- CLIR
- CMIS
- CMISE
- CMRS
- CN
- COF
- COFDM
- CoLR
- COMSAT
- COO
- COR-PSK
- COT
- CP
- CP
- CPFSK
- CPM
- CPW
- CQT
- CR
- CR
- CRA
- CSA
- CS-ACELP
- CSC
- CSCW
- CT
- CT-2
- CTP
- CTP
- CTR
- CTS
- CUG
- CVSD
- CW
- D/C
- DAC
- DAMA
- DAMPS
- DAV
- DAVID
- DBF
- DBR
- DBS
- dBW
- DCA
- DCCH
- DCF
- DCH
- DCI
- DCN
- DDL
- DDS
- DECT
- Demod
- DEMUX
- DFB
- DFF
- DFH
- 3C
- FCCU
