کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
852354 909372 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Trellis ternary line coding scheme for asynchronous optical CDMA systems
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی (عمومی)
پیش نمایش صفحه اول مقاله
Trellis ternary line coding scheme for asynchronous optical CDMA systems
چکیده انگلیسی
In this paper, we investigate the employment of a ternary line coding technique based on Ungerboeck's trellis-coded method in asynchronous optical CDMA systems. The ternary coding we use is predicated upon the equal-weight orthogonal (EWO) scheme. Each user transmits two mutually orthogonal signature sequences to represent “+1” and “−1”, respectively, and nothing is transmitted for “0”. The receiver employs a maximum-likelihood soft-decoder to select the path with minimum Euclidean distance as the preferred path. This trellis ternary coding scheme applies set partitioning with partially overlapping subsets to increase the free Euclidean distance, which considerably improves system performance. Furthermore, due to line coding technique, such scheme comprises sufficient clock information, and thus benefits for baseband timing extraction (i.e. clock recovery). Numerical results reveal that the proposed trellis ternary coding scheme can significantly reduce the error floor and allow more active users to be accommodated in the network.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Optik - International Journal for Light and Electron Optics - Volume 120, Issue 15, October 2009, Pages 765-772
نویسندگان
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