What is Cyclic prefix in LTE ?
The guard period after each rectangular pulse carrying the modulated data symbol is a simple and efficient method to deal with multi-path reception. The cyclic prefix (CP) simply consists of…
Tag: cdma
cdma technology optimization
Pulse shaping and spectrum in LTE
RF engineering is a trade off between: required radio spectrum (bandwidth), speed of data transmission (bit rates) and complexity of implementation. The pulse form used to modulate complex data symbols…
How Many CODES in CDMA?
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…
How Modulation-QPSK in CDMA ?
In an actual application, the system implements the modulation in this way: as shown above, I and Q channel sequences in the figure represent two channels of cyclic PN…
Types of Handover in LTE
The Handover is the process of transferring an ongoing call or data session fromone cell connected to the core network to another It is transparent for the end user It…
CDMA Protocol Stacks
The original release of the EIA/TIA-95-B standard defined the protocol messages and formats to be used in the CDMA system. This release is know as Revision 0 of the IS-95…
Ranging in Wimax
The initial range is the process of estimating the distance or propagation time between a transmitter and a receiver. Area information can be used to assist in setting operating parameters…
EVDO reverse Link
Here I write about EVDO (HSD) reverse channel in short or summarize defination. The EVDO channels for the reverse connection have a similar structure as for CDMA2000. The reverse link…
CDMA System Time
For both mobiles and base station in direct sequence CDMA must be synchronized. In the IS-95A system, synchronization is based on the Global Positioning Satellite system time. The CDMA system…
How Forward Link Channel Format in CDMA
The Base Station transmitter signal is, however, the composite of many channels (with a minimum of four). The Pilot channel is unmodulated (Walsh code 0); it consists of only the…
Reverse Link Traffic Channel Physical Layer in CDMA
The CDMA reverse link uses a different coding scheme to transmit data. Unlike the forward link, the reverse link cannot support a pilot channel for synchronous demodulation (since each mobile…
Forward Traffic Channel of CDMA
Forward Traffic Channel is used to Transmit Data and Signaling Information. Symbol repetition makes symbol streams at different rates adapted to those at the rate of 19.2k. The original symbol…