What is a scrambling code?
Scrambling Codes are used to identify and distinguish cells from one another in WCDMA networks. These SCs are reported by the mobile users to the network to declare which cells they are able to connect to.
What are channelisation codes used for?
The channelization codes are Orthogonal Variable Spreading Factor (OVSF) codes. They are used to preserve orthogonality between different physical channels. They also increase the clock rate to 3.84 Mcps.
What is channelization code and scrambling code?
Channelization codes are generated recursively to form a binary tree structure (see Figure 15.20). Spreading is used in combination with scrambling. Scrambling is used on top of spreading to separate mobile terminals or cells from each other. Scrambling does not change the chip rate nor the bandwidth.
What are the two different types of code used in Wcdma?
The first using the OSVF code and the second using a scrambling PN code. These codes are used to provide different levels of separation. The OVSF spreading codes are used to identify the user services in the uplink and user channels in the downlink whereas the PN code is used to identify the individual node B or UE.
Why scrambling is used in 5g?
There are two main reasons why scrambling is used: To enable accurate timing recovery on receiver equipment without resorting to redundant line coding.
What is scrambling code in LTE?
It is “Scrambling Code”. By using the scrambling code, NodeB can separate signals coming simultaneously from many different UEs and UE can separate signals coming simultaneously from many different NodeB. A specific bit sequence which is used for scrambling is called ‘Scrambling code’.
What does WCDMA mean for phones?
Wideband Code Division Multiple Access
WCDMA (Wideband Code Division Multiple Access) UMTS standard for 3G digital mobile networks, using CDMA technology. It is the evolution path for GSM and EDGE to UMTS and offers increased voice capacity and theoretical peak data speeds of up to 2 Mbps.
What is difference between WCDMA and LTE?
In general, WCDMA is considered as 3G technology while LTE is considered as 4G technology. LTE provides higher data rates than WCDMA by achieving higher spectral efficiency. Also, LTE technology provide more flat architecture that is mainly focused on IP packet based services than that of the WCDMA.
Why we perform Channelisation or spreading before scrambling?
spreading vs scrambling Both are basically used to spread energy over the band. This helps in preventing unathorized access of the signal by intruders. This is because signal goes below noise power level. User having known spreading code(PN code or channelization code) can despread the spreaded signal.
What is scrambling in LTE?
Is WCDMA 2G or 3G?
WCDMA is the 3G network that uses radiofrequency to transfer data in the form of calls, messages, or the internet which is also called UMTS. GSM represents 2G networks that were developed way before WCDMA and helps to transfer data through radio technology in the system.
What is the difference between WCDMA and CDMA?
The main difference between WCDMA and CDMA is that they are designed to work with different networks. WCDMA is a 3G technology designed to work alongside the 3G GSM network. CDMA, on the other hand, is a 2G technology that is a direct competitor to GSM.
How are channelization codes defined in the code tree?
Each level in the code tree defines channelization codes of length Spreading Factor (SF), corresponding to a spreading factor of SF. All codes within the code tree cannot be used simultaneously within one cell.
How many bits are there in the channelization code set?
and the channelization code set consists of seven bits xccs,1, xccs,2, …, xccs,7. The first three bits ( code group indicator) are determined as the unsigned binary representation of the following expression
What are channelization codes in WCDMA?
Channelization codes are generated recursively to form a binary tree structure. In a WCDMA system, isolation between users in the downlink is accomplished through the combination of user-specific channelization codes and cell-specific scrambling codes.
Why Over Channelization should be avoided?
Over Channelization should be avoided because it could create confusion and worsen operations. Channelization – It is the separation or regulation of conflicting traffic movements into definite paths of travel by traffic islands or pavement marking to facilitate the safe and orderly movements of both vehicles and pedestrians.