BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:(Research) Performance modelling and design of bit-interleaved cod
 ed modulation - William R. Carson
DTSTART:20090526T130000Z
DTEND:20090526T140000Z
UID:TALK17491@talks.cam.ac.uk
CONTACT:Ioannis Chatzigeorgiou
DESCRIPTION:This talk examines the design of a _bit-interleaved coded-modu
 lation_ with _iterative decoding_ (BICM-ID) system for transmission over a
  _quasi-static fading_ (QSF) channel. We illustrate the design process for
  matching the extrinsic information transfer (EXIT) chart curves for _16-Q
 AM_ mapping schemes and memory-two recursive systematic convolutional (RSC
 ) codes. \n\nThis design process is extremely complex and we define two cl
 assification metrics that enable us to reduce the number of mapper and enc
 oder combinations. We use the _probability of a decoding erasure_ to separ
 ate all 22 memory-two RSC codes into five groups. We conjecture that the c
 odes in each group will have the same FER performance when coupled with th
 e same mapping scheme. Similarly\, we conjecture that all mapping schemes 
 with the same _distance spectrum_ will have identical FER performance curv
 es when coupled with the same encoding scheme. We provide evidence to supp
 ort the validity of these conjectures\, which allow us to make the set of 
 16-QAM mapping schemes practically searchable when attempting to find the 
 best match for a particular encoder. \n\nFinally\, we demonstrate the _pra
 ctical methodology_ for finding the best FER performance that can be achie
 ved by a BICM-ID scheme using a memory-two RSC code matched to a 16-QAM ma
 pping scheme for transmission over a QSF channel with various levels of an
 tenna diversity. For example\, by using our design framework\, we observe 
 that we are able to achieve a gain of 0.2 dB at a FER of 2x10^-2^ and a ga
 in of 0.4 dB at a FER of 4x10^-4^ in the low and the high antenna diversit
 y scenarios respectively over the RSC memory-two code (1\, 5/7) coupled wi
 th the best mapping schemes found in the literature.
LOCATION:SS03\, William Gates Building
END:VEVENT
END:VCALENDAR