How the Ovsf code is generated?
Table of Contents
How the Ovsf code is generated?
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. It follows by induction that the rows of CN are orthogonal.
What is Ovsf in UMTS?
OVSF code channel assignment with dynamic code set and buffering adjustment for UMTS. In WCDMA, orthogonal variable spreading factor (OVSF) codes are assigned to different users to preserve the orthogonality between users’ physical channels. The data rate supported by an OVSF code depends on its spreading factor (SF).
How do you generate orthogonal codes?
The simplest way to get an orthogonal code dictionary is to generate a Hadamard/Walsh matrix. All the rows and columns of this matrix are mutually orthogonal. You can use a couple of its rows or columns as your codes.
What is a spreading code?
In DSSS, a spreading code is used to map each data bit in the original signal to multiple bits in the transmitted signal. The pseudorandom code (spreading code) spreads the input data across a wider frequency range compared to the input frequency. In the frequency domain, the output signals appear as noise.
What is chip in wireless communication?
In digital communications, a chip is a pulse of a direct-sequence spread spectrum (DSSS) code, such as a pseudo-random noise (PN) code sequence used in direct-sequence code division multiple access (CDMA) channel access techniques. …
How many scrambling codes are there in UMTS?
15.6 Spreading and Scrambling in UMTS
| Synchronization codes | Scrambling codes, downlink | |
|---|---|---|
| Length | 256 chips | 38,400 chips |
| Duration | 66.67 μs | 10 ms |
| Number of codes | 1 primary code/16 secondary codes | 512 primary/15 secondary for each primary code |
| Spreading | No, does not change bandwidth | No, does not change bandwidth |
How codes are used in UMTS?
The channelisation codes used in Universal Mobile Telecommunications System (UMTS) belong to the family of OVSF codes. They are organised according to a code tree structure. OVSF codes are primarily used to preserve orthogonality between different channels.
What is orthogonal code?
CDMA (Code Division Multiple Access) is a communication technique that allows multiple users to communicate simultaneously over one frequency. This is achieved through the use of spreading codes, whereby a single data bit is “spread” over a longer sequence of transmitted bits. Such codes are known as orthogonal codes.
Which uses orthogonal code?
Synchronous CDMA
6. Which uses orthogonal codes? Explanation: Synchronous CDMA uses orthogonal codes and asynchronous CDMA uses pseudorandom codes.
What is CDMA and TDMA?
TDMA stands for Time Division Multiple Access. CDMA stands for Code Division Multiple Access. 2. In this, only the sharing of time of satellite transponder takes place. In this, there is sharing of both i.e. bandwidth and time among different stations takes place.
What is a chip code?
CHIPS stands for the Clearing House Interbank Payments System Universal Identifier. The CHIPS Uid is a six-digit code that contains all the information that is necessary to identify the person who is wiring the money.