Signal Fading
A transmitted signal changes as it travels to the receiver. The effect of these changes is commonly referred to as fading. The fading results from the superimposition of transmitted signals,…
Telecom Techniques Guide
Here You Get how 3G work, Go inside WCDMA Technology and wcdma rf optimization.
A transmitted signal changes as it travels to the receiver. The effect of these changes is commonly referred to as fading. The fading results from the superimposition of transmitted signals,…
3G is new upgraded cdma technology, in simple word its Wide band Code Devision Multiple Access Technology (WCDMA). This is first technology in which video call possible means voice and…
The 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunication associations, to make a globally applicable third generation 3G mobile phone system specification within the scope of…
A data-modulation scheme defines how the data bits are mixed with the carrier signal, which is always a sine wave. There are three basic ways to modulate a carrier signal…
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…
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…
Different modulation methods corresponding to different transmitting abilities in air interface. R99/R4: QPSK HSDPA: QPSK or 16QAM The UTRAN air interface uses QPSK modulation in the downlink, although HSDPA may…