Tag: 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…

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…

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…

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…

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…

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…

Naturally, the first application for which a wireless alternative was developed and deployed was voice telephony. These systems, called wireless local-loop (WLL), were quite successful in developing countries such as…

Reverse power control Open loop power control Closed loop power control Inner loop power control:  800 Hz Outer loop power control Forward power control Message transmission mode: threshold transmission periodic…

The long code is a PN sequence with period of 242-1chips The functions of a long code: Scramble the forward CDMA channel Control the insertion of power control bit Spread…

It can be seen from the figure that the data are read row by row into an interleaver at the transmit end,read column by column out (this process is called…