Tag Archives: cdma

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

Forward Traffic Channel of CDMA

Forward Traffic Channel is used to Transmit Data and Signaling Information. Symbol repetition makes symbol streams at different rates adapted to those at the rate of 19.2k. The original symbol

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

Ranging in Wimax

Since each MS has a unique distance from the base station, it is critical in the uplink to synchronize the symbols and equalize the received power levels among the various