There Are Three Codes in CDMA PN Long Code,PN Short Code & Walsh Code. PN Long Code The Long Code is a PN sequence that is 242 – 1 bits (chips) long. The long code is used to encrypt user information. Both the base station and the mobile unit have knowledge of this sequence at … Read more
Dsss – Direct sequence spread spectrum DSSS – Direct Sequence Spread Spectrum is a spread spectrum technology in which original data is expand using PN code randomly to reduce noise and this also provide high security to data as is scrambled data. Spread spectrum technology spread spectrum technology used in CDMA and Cdma is a … Read more
The 850MHz CDMA band is most popularly used all over the world.This band as mentioned in the previous slide works between 824-849MHz Used for the Reverse link communication 869-894MHz Used for the Forward link communication The CDMA band is divided into sub bands as shown above.The Total Band of 25MHz is divided into … Read more
PN Code Generation PN Code Generation PN codes are generated from prime polynomials using modulo 2 arithmetic. The state machines generating these codes are very simple and consist of shift registers and XOR gates . Masking will cause the generator to produce the same sequence, but offset in time PN Offset (Masking) Masking … Read more
• Definition: Orthogonal functions have zero correlation. Two binary sequences are orthogonal if the process of “XORing” them results in an equal number of 1’s and 0’s. Example: 0000 (XOR) 0101 —— 0101 • Generation Sequence: – Seed – Repeat: right & below – Invert: diagonally The above table of … Read more
Google has reported that its first-quarter revenues jumped by nearly a third to US$14 billion, while profits rose to US$3.35 billion, compared to US$2.89 billion a year ago. Google said that its revenues from outside of the United States totaled $7.1 billion, representing 55% of total Google revenues in the first quarter of 2013, compared … Read more