How to Reverse Access Channel Work in CDMA?
Reverse Access Channel used by MS Initiate Communication or Respond to Paging Channel. A reverse channel is first spread with WALSH to 307.2Kbps and then becomes 1.2288Mcps after long code…
Tag: cdma
cdma technology optimization
WCDMA Channelization Code
OVSF Code (Orthogonal Variable Spreading Factor) is used as channelization code Orthogonal codes are easily generated by starting with a seed of 1, repeating the 1 horizontally and vertically, and…
What is Work of Paging Channel in CDMA?
The paging channel transmits: System parameters message Access parameters Neighbors list CDMA channels list message The paging channel accomplishes: Paging to MS Assign traffic channel to MS The frame length…
How Sync Channel work in CDMA?
A long code is used for scrambling. However, a long code has too long a period, which cannot be wholly used for scrambling. We can only sample some chips of…
What is Basic work of Pilot Channel in CDMA?
A pilot channel: Assist mobile station to be connected with CDMA network Handles multi-path searching Provide the phase reference for coherent demodulation and help the mobile station estimate the transmission…
Transmit Diversity of CDMA
Diversity technology means that after receiving two or more input signals with mutually uncorrelated fading at the same time, the system demodulates these signals and adds them up. Thus, the…
What is T_ADD,T_DROP and T_TDROP in CDMA?
Pilot Detection Threshold (T_ADD) Any Pilot that is strong but is not in the Handoff Direction Message is a source of interference. This Pilot should be immediately moved into the…
List of Uplink and Downlink Physical Channel of WCDMA
Downlink Physical Channel of WCDMA Downlink Dedicated Physical Channel: Downlink DPCH Downlink Common Physical Channel: Common Control Physical Channel (CCPCH) Synchronization Channel ( SCH) Paging Indicator Channel (PICH) Acquisition Indicator…
Basic Work of WCDMA Physical Channel
A physical channel is defined by a specific carrier frequency, code (scrambling code, spreading code) and relative phase. In UMTS system, the different code (scrambling code or spreading code) can distinguish the…
Specifications of WCDMA
Channel Bandwidth 5 MHz Duplex Mode FDD and TDD Downlink RF Channel Structure Direct Spread (DS) Chip Rate 3.84 Mcps Frame Length 10 ms Spreading Modulation Balanced QPSK (downlink) Dual-channel…
Main Characterictics of WCDMA
Support two basic modes: FDD and TDD modes High chip rate (3.84 Mcps) and data rates (up to 2 Mbps) Employs coherent detection on uplink and downlink based on the…
WiMAX versus 3G and Wi-Fi
How does WiMAX compare with the existing and emerging capabilities of 3G and Wi-Fi? The throughput capabilities of WiMAX depend on the channel bandwidth used. Unlike 3G systems, which have…