Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

channel coding in gsm

Status
Not open for further replies.

mehdi_an

Advanced Member level 4
Joined
Jan 17, 2007
Messages
106
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,296
Activity points
1,813
rpe ltp

hi all
i want know that in gsm system what kind are there error coding?
thabks.
 

GSM use several types of channel coding: block coding, convolutional coding and interliving.

More detail in book:GSM Switching Services & Protocols or standarts
 

    mehdi_an

    Points: 2
    Helpful Answer Positive Rating
GSM divides output of the RPE-LTP speech coder into 3 categories :
1-50 bits called "Very Important bits"
2-132 bits called "Important bits"
3-78 bits called " Not so Important bits"

the 50 bits are very important for having intelligible speech ,so they're applied to both block coder and 1/2 rate convolutional encoder .The 132 bits are important but not as important as the 50 bits so they're applied only to the convolutional encoder .Speech can be understood even if an error occured at the last 78 bits so no channel coding is applied to them .Afterwards, interleaving is apllied to mitigate burst errors .
 

    mehdi_an

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top