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 against random errors, but it is quite vulnerable to bursts of errors, which are typical in mobile radio systems. The especially fast moving UE in … Read more
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 Coding Convolutional Coding (1/2, 1/3) Turbo Coding (1/3) UTRAN employs two FEC schemes: convolutional codes and turbo codes. The idea is to add redundancy … 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
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
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 to radio signals from digital signals. Bit, Symbol, Chip Bit : data after source coding Symbol: data after channel coding … Read more
Formulated by the European standardization organization 3GPP, the core networkevolves on the basis of GSM/GPRS and can thus be compatible with the existingGSM/GPRS networks. It can be based on the TDM, ATM and IP technologies toevolve towards the all-IP network architecture. Based on the ATM technology, theUTRAN uniformly processes voice and packet services and evolves … Read more
There are different band in different country but most of commonly used band we will discuss here. Main bands : means basic band when 3G commercial launch by Private or public sector. 1920 ~ 1980MHz / 2110 ~ 2170MHz Supplementary bands: different country maybe different as per government selling in auction. 1850 ~ 1910 MHz / 1930 MHz … Read more
How 3G Spectrum Allocation? 3G Spectrum Allocation is different in different country but mainly its all having as per below figure. ITU has allocated 3G Spectrum Allocation 230 MHz frequency for the 3G mobile communication system IMT- 2000: 1885 ~ 2025MHz in the uplink and 2110~ 2200 MHz in the downlink. Of them, the frequency … Read more
In Long-Term Evolution (LTE), the channel architecture refers to the organization and allocation of different types of channels used for communication between the User Equipment (UE) and the Evolved NodeB (eNB). LTE employs a flexible and efficient channel architecture to support various services and optimize resource utilization. Here are key components of the channel architecture … Read more
How MAC Protocol Work In LTE? The MAC protocol provides the following services: Logical Channel to Transport channel mapping Scheduling: There is no dedicated channel allocated to a UE. Time and frequency resources are dynamically shared between the users in DL and UL. The scheduler is part of the MAC layer and controls the assignment … Read more