What is a channelization code?
The channelization codes are Orthogonal Variable Spreading Factor codes that preserves the orthogonality between a user’s different physical channels. The OVSF codes can be defined using a code tree.
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. The OVSF codes are defined using a code tree.
What are the two different types of code used in WCDMA?
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.
What are the 3 parameters based on which scrambling code is generated?
The Scramble Type field has three modes: Standard, Right Alternate, and Left Alternate. The standard scramble type has a value of zero and does not contribute to the scramble code. Selecting the right alternate adds 16384 to the actual scramble code; the left alternate adds 8192.
What is scrambling in LTE?
In telecommunications and recording, a scrambler (also referred to as a randomizer) is a device that manipulates a data stream before transmitting. The manipulations are reversed by a descrambler at the receiving side. Scrambling is widely used in satellite, radio relay communications and PSTN modems.
What is Ovsf in mobile computing?
The OVSF Code Generator block generates an OVSF code from a set of orthogonal codes. OVSF codes were first introduced for 3G communication systems. OVSF codes are primarily used to preserve orthogonality between different channels in a communication system.
What is spreading factor in WCDMA?
WCDMA uses Direct Sequence spreading, where spreading process is done by directly combining the baseband information to high chip rate binary code. The Spreading Factor is the ratio of the chips (UMTS = 3.84Mchips/s) to baseband information rate. Spreading factors vary from 4 to 512 in FDD UMTS.
Which codes are used as channelization codes to separate physical channels of a UE?
Purpose of WCDMA Channelization Code
- Channelization code is used to distinguish different physical channels of one transmitter.
- For downlink, channelization code ( OVSF code ) is used to separate different physical channels of one cell.
What is spreading factor?
The spreading factor, in this case, is the ratio of the total number of channels to the number of channels used for data hiding.
Why scrambling is used in 5g?
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.
What is chip rate in WCDMA?
The basis for the physical layer of WCDMA is spreading of the data to be transmitted to the chip rate corresponding to 3.84 Mchip/s using channelization codes. It is also responsible for coding, transport-channel multiplexing, and modulation of the radio-frequency carrier.