WCDMA
Passive Distributed Antenna Systems in 3G Various internal antenna solution can meet the different needs of the deployment. DAS solution distributes a plurality of antenna nodes throughout the coverage area. Each antenna assembly can transmit and receive signals 3G. The uplink signals from all the antenna units are collected in a central point, the point … Read more
WCDMA Network Architecture The Wideband Code Division Multiple Access (WCDMA) network architecture: 1. User Equipment (UE): The UE, often a mobile phone or data card, is the device used by the end-user to access the WCDMA network. 2. UMTS Terrestrial Radio Access Network (UTRAN): UTRAN is the radio access network in WCDMA, consisting of NodeB … Read more
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, in which differences in attenuation, delay and phase shift have occurred. Slow fading: In case shadow effect is caused by obstacles, and the receiving signal … Read more
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 data simultaneously transmitted and received between mobile or data card and BTS – Base Transmission Station. WCDMA Having Below Characterictics Support two basic modes: FDD and … Read more
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 China, India, Indonesia, Brazil, and Russia, whose high demand for basic telephone services could not be served using existing infrastructure. In fact, WLL systems based … Read more
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 the International Mobile Telecommunication-2000 project of the International Telecommunication Union (ITU). 3GPP specifications are based on evolved Global Systel for Mobile Communication (GSM) specifications. 3GPP … Read more
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 use of pilot symbols Inter-cell asynchronous operation Fast adaptive power control in the downlink based on SIR Provision of multirate services Packet data Seamless inter-frequency … Read more
How Process Gain works in 3G? Process Gain = 10 Log (Chip rate/Bit Rate) Process gain differs for each service. If the service bit rate is greater, the process gain is smaller, UE needs more power for this service, then the coverage of this service will be smaller, vice versa. For common services, the bit … Read more
AMR (Adaptive Multi-Rate) Speech A integrated speech codec with 8 source rates The AMR bit rates can be controlled by the RAN depending on the system load and quality of the speech connections Video Phone Service H.324 is used for VP Service in CS domain Includes: video codec, speech codec, data protocols, multiplexing and etc. … Read more
Block coding is used to detect if there are any uncorrected errors left after error correction. The cyclic redundancy check (CRC) is a common method of block coding. Adding the CRC bits is done before the channel encoding and they are checked after the channel decoding. During the transmission, there are many interferences and fading. … Read more