Orthogonal Code Usage – Coding & Decoding in WCDMA
How Orthogonal Code works in WCDMA? 1.Coding By spreading, each symbol is multiplied with all the chips in the orthogonal sequence assigned to the user. The resulting sequence is processed…
Category: WCDMA
Here You Get how 3G work, Go inside WCDMA Technology and wcdma rf optimization.
WCDMA Network Architecture
WCDMA including the RAN (Radio Access Network) and the CN (Core Network). The RAN is used to process all the radio-related functions, while the CN is used to process all…
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,…
Emergence of Standards-Based Technology
In 1998, the Institute of Electrical and Electronics Engineers (IEEE) formed a group called 802.16 to develop a standard for what was called a wireless metropolitan area network, or wireless…
Spreading Technology in WCDMA
Spreading consists of 2 steps: Channelization operation, which transforms data symbols into chips Scrambling operation is applied to the spreading signal Spreading means increasing the bandwidth of the signal beyond…
Spectrum Analysis of Spreading & Dispreading in WCDMA-3G
How Spreading & Dispreading in WCDMA-3G ? Traditional radio communication systems transmit data using the minimum bandwidth required to carry it as a narrowband signal. CDMA system mix their input…
Correlation in WCDMA
How Correlation works in WCDMA ? Correlation measures similarity between any two arbitrary signals. Identical and Orthogonal signals: Correlation is used to measure similarity of any two arbitrary signals. It…
WCDMA Interleaving
How WCDMA Interleaving ? Effect Interleaving is used to reduce the probability of consecutive bits error Longer interleaving periods have better data protection with more delay Channel coding works well…
WCDMA Channel Coding
Effect Enhance the correlation among symbols so as to recover the signal when interference occurs Provides better error correction at receiver, but brings increment of the delay Channel Types No…
WCDMA Block Coding – CRC
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…
WCDMA Source Coding
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…
Processing Procedure of WCDMA System
Source coding can increase the transmitting efficiency. Channel coding can make the transmission more reliable. Spreading can increase the capability of overcoming interference. Through the modulation, the signals will transfer…