Procedure to demap softdecision bits to dibits in multi-modulation systems
Original Publication Date: 2001-Dec-01
Included in the Prior Art Database: 2003-Jul-23
Jürgen Schüling: AUTHOR [+1]
The invention consists of a distribution of softdeci- sion bits for dibit processing. At present it is solved through the use of several demodulators and bit serial processing units. The decoding of softdecision bits is usually achieved by converting the parallel softdecision inputs to serial and decoding the serial bits. The term dibit is syno- nym für two parallel bits to double the process speed.
Information / Kommunikation
Procedure to demap softdecisionbits to dibits in multi-modulationsystems
Idee: Jürgen Schüling, Bocholt;
Dr. Kalyan Koora, Bocholt
The invention consists of a distribution of softdeci-sion bits for dibit processing.
At present it is solved� through� the� use� of� severaldemodulators and bit serial processing units.
The decoding of softdecision bits is usually achievedby converting the parallel softdecision inputs to serialand decoding the serial bits. The term dibit is syno-nym für two parallel bits to double the process speed.
The new procedure enables the processing of dibitsindependent of the modulation type without convert-
ing them either into serial bit current or using differ-ent demodulators. The incoming dibits are first storedin� register� banks.� The� switch� circuit� encodes� thesoftdecision bits depending on the modulation type tothe corresponding dibits. After switching the softde-cision bits, they can either be used directly or storedin registers to pipeline the process.
The advantages are a� doubling� of� execution� timethrough� the� use� of� dibits� instead� of� serial� bits, anoptimal use of logic resources and a changing of themodulation type during a transmission.
With this method it is not only possible to increasethe processing speed but also simplifies the hardwarerealisation by avoiding the use of multiple demodu-lators.
In figure 1 you can see an example block diagrammfor demodulate soft and hard decision bits to dibits...