A pilot channel: Assist mobile station to be connected with CDMA network Handles multi-path searching Provide the phase reference for coherent demodulation and help the mobile station estimate the transmission power The mobile station measures and compares the pilot channel powers from the base stations during the handoff Forward pilot channel is spread over W0 … Read more
Diversity technology means that after receiving two or more input signals with mutually uncorrelated fading at the same time, the system demodulates these signals and adds them up. Thus, the system can receive more useful signals and overcome fading. A mobile communication channel is a multi-path fading channel and any transmitted signal reaches a receive … Read more
Pilot Detection Threshold (T_ADD) Any Pilot that is strong but is not in the Handoff Direction Message is a source of interference. This Pilot should be immediately moved into the active set for handoff to avoid voice/data degradation or a possible drop call. T_ADD affects the percentage of MS in handoff. It should be low … 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
Typically, the data rate available at the radio interface is lower than the data rate available on the network interfaces. Thus, when a certain rate data service is higher than the data rate of the LTE radio interface, this leads to buffering in the UE and the eNodeB. This buffer allows the programmer to the … Read more