In this paper we formally analyze the interleaver and code design for QAM-based BICM transmissions using the binary reflected Gray code. We develop analytical bounds on the bit error rate and we use them to predict the performance of BICM when unequal error protection (UEP) is introduced by the constellation labeling. Based on these bounds the optimum design of interleaver and code is found, and numerical results for representative configurations are presented. When the new design is used, the improvements may reach 2 dB, and they are obtained without complexity increase. We also introduce the concept of generalized optimum distance spectrum convolutional codes, which are the optimum codes for this scenario.
Index TermsBICM, interleaver design, multiple interleaver, optimum distance spectrum codes, QAM, UEP.
When isometrically contracting muscles are subjected to a quick release followed by a shortening ramp of appropriate speed (V(o)), tension decays from its value at the isometric plateau (P(o)) to <0. 05 P(o) with the same time course as the quick part of the release; thereafter, tension remains at a negligible level for the duration of the shortening ramp. X-ray diffraction data obtained under these conditions provide evidence that 1) at V(o) very few heads form an actomyosin complex, while the number of heads doing so at P(o) is significant; 2) relative to rest the actin filament at V(o) is approximately 0.12% shorter and more twisted, while it is approximately 0.3% longer and less twisted at P(o); and 3) the myosin heads attaching to actin during force development do so against a thin filament compliance of at least 0.646 +/- 0.046% nm per P(o).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.