Tag : power control

Long Code & Short Code In CDMA

Long Code & Short Code In CDMA

The long code is a PN sequence with period of 242-1chips The functions of a long code: Scramble the forward CDMA channel Control the insertion of power control bit Spread the information on the
Interleaving in CDMA

Interleaving in CDMA

It can be seen from the figure that the data are read row by row into an interleaver at the transmit end,read column by column out (this process is called interleaving) and propagated after
WCDMA Block Coding – CRC

WCDMA Block Coding – CRC

Block coding is used to detect if there are any uncorrected errors left after error correction. The cyclic redundancy check (CRC) is a common method of block coding. Adding the CRC bits is done
Soft/Softer Handoff in CDMA

Soft/Softer Handoff in CDMA

Multi-path combination in the BSC during soft handoffMulti-path combination in the BTS during softer handoffs       Soft handoff means that during the handoff of a mobile station at the coverage edge areas of two
Forward Power Control in CDMA

Forward Power Control in CDMA

Message Transmission Mode MS measures the frame quality and informs the base station to the result i.e. whether it is in the threshold or periodical  mode. Base station determines whether  to change the forward
Scrambling (M) sequence in CDMA

Scrambling (M) sequence in CDMA

  Two points are important here:  Maximum number of shift register (N)  Mask The period of out put sequence is 2N-1 bits Only sequence offset is change when the mask is changed PN stands
WCDMA Interleaving

WCDMA Interleaving

How WCDMA Interleaving ? Effect Interleaving is used to reduce the probability of consecutive bits error Longer interleaving periods have better data protection with more delay Channel coding works well against random errors, but
Uplink Logical Channel in GSM

Uplink Logical Channel in GSM

1. Random access channel (RACH) It is an uplink channel used for MS randomly access to network by requesting for an SDCCH. The request includes a 3bit setup reason (call request, paging response, location
Power ramping in LTE

Power ramping in LTE

Open loop power control together with optional power ramp-up is used during the random access process at the beginning of the connection until more accurate control information is available. Power loss due to transmission distance depends
Principle of Power control in LTE

Principle of Power control in LTE

Power control - already being applied in 2nd and 3rd generation networks - has high potential for improvement of the performance of mobile networks. Main benefits are: 1. It can bring down the interference