CDMA
E744870
CDMA (Code Division Multiple Access) is a digital cellular technology that allows multiple users to share the same frequency spectrum simultaneously by assigning unique codes to each communication.
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
digital cellular technology
ⓘ
multiple access scheme ⓘ |
| allows | multiple users to share the same frequency band simultaneously ⓘ |
| appliedIn | 3GPP UMTS as WCDMA ⓘ |
| basedOn | spread-spectrum modulation ⓘ |
| canBe |
asynchronous
ⓘ
synchronous ⓘ |
| contrastedWith |
FDMA
NERFINISHED
ⓘ
TDMA ⓘ |
| developedBy | Qualcomm NERFINISHED ⓘ |
| distinguishesUsersBy | unique spreading codes ⓘ |
| enables | higher user capacity compared to FDMA and TDMA in many scenarios ⓘ |
| feature |
frequency reuse of 1
ⓘ
inherent security through code spreading ⓘ resistance to narrowband interference ⓘ soft capacity limit ⓘ soft handoff ⓘ |
| fullName | Code Division Multiple Access NERFINISHED ⓘ |
| introducedInCommercialSystems | 1990s ⓘ |
| mitigates | multipath fading through diversity combining ⓘ |
| operatesIn | code domain ⓘ |
| requires |
RAKE receivers for multipath combining
ⓘ
power control ⓘ synchronization between base station and mobiles in some variants ⓘ |
| standardizedBy |
3GPP2
NERFINISHED
ⓘ
TIA NERFINISHED ⓘ |
| suffersFrom | near–far problem ⓘ |
| supports |
data communication
ⓘ
packet data services ⓘ voice and data multiplexing on same carrier ⓘ voice communication ⓘ |
| usedIn |
3G mobile systems
ⓘ
GPS spread-spectrum signaling ⓘ cellular networks ⓘ military communication systems ⓘ satellite communication systems ⓘ |
| usedInStandard |
CDMA2000
NERFINISHED
ⓘ
IS-95 NERFINISHED ⓘ WCDMA NERFINISHED ⓘ cdmaOne NERFINISHED ⓘ |
| uses |
Walsh codes in IS-95 downlink
ⓘ
chip rate higher than data rate ⓘ orthogonal codes for downlink in many systems ⓘ pseudorandom noise sequences ⓘ spread spectrum technology ⓘ spreading codes ⓘ |
| variant |
direct-sequence CDMA
ⓘ
frequency-hopping CDMA ⓘ |
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.