Iterative Channel Estimation and LDPC Decoding over Flat-Fading Channels: A Factor Graph Approach

A novel melt processable polyester urea is provided which is capable of forming an anisotropic melt phase. Such polyester urea includes three essential moieties comprising (1) 6-oxy-2-naphthoyl moiety, (2) dicarboxyaryl urea moiety as defined herein, and (3) dioxyaryl moiety. Additional ester- and/or amide-forming moieties may be present in the polyester urea polymer chain so long as they do not destroy the anisotropic character of the polymer melt phase or unduly raise its melting temperature. The polyester urea is suitable for use in high performance applications, and may be used to form via melt processing industrial yarns, reinforcing fibers, films, and molded articles. The presence of the highly polar urea linkages in the polymer chain is believed to beneficially provide strong electron interactions between adjoining polymer chains and between the polyester urea and other materials, such as rubber matrices, dyes, etc.

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