A novel class of constant-length variable-weight optical orthogonal codes is proposed that can support multimedia services with different data rates and quality-of-service requirements. The construction is based on the pairwise balanced designs, or more specifically, on an incidence structure defined on an integer lattice. Proposed codes are suitable for spectral-amplitude coding, fast-frequenc...

multi-part words in english language are hyphenated and hyphen is used to separate different parts. persian language consists of multi-part words as well. based on persian morphology, half-space character is needed to separate parts of multi-part words where in many cases people incorrectly use space character instead of half-space character. this common incorrectly use of space leads to some s...

A forward-error correction )FEC) scheme based on low-density parity check (LDPC) codes and iterative decoding using belief propagation in code graphs is presented in this paper. We show that LDPC codes provide a significant system performance improvement with respect to the state-of-the-art FEC schemes employed in optical communications systems. We present a class of structured codes based on m...

Turbo decoding is viewed as superior alternate decoding technique in communication system, the circuit complexity and power consumption of turbo decoder implementation can often be prohibitive for power constrained system. To address these issues a power efficient turbo decoder based on soft out viterbi algorithm is designed. SOVA based turbo decoder can be implemented with high throughput and ...

The key objective of this project is to design a decoder which can be used for hardware purpose. A decoder is a combinational circuit that converts binary information from n input lines to a maximum of m=2 output lines. In this paper are design of Dynamic decoder and Tree Decoder. Also shows a comparative analysis of tree decoder with corresponding dynamic decoder and tree decoder highlights th...

In this paper, we have presented an efficient original architecture of all-optical 2 × 4 photonic crystal decoder based on non-linear ring resonators. The fundamental structure is a square lattice 2D GaAs rods, operating around the wavelength 1.55 µm. proposed composed combiner with three input ports, where port E used for excitation and A1, A2 are control optical switch four output it nonlinea...

—This article presents an FPGA implementation of an ultra-high-speed Reed-Solomon (RS) turbo decoder. A performance analysis is performed showing that RS Block Turbo Codes (RS-BTC) have decoding performance equivalent to Bose Ray-Chaudhuri Hocquenghem-Block Turbo Codes (BCH-BTC). A ratio between the decoder throughput and the decoder area is used to show the higher ef ciency of the RS full para...

We propose use of QR factorization with sort and Dijkstra’s algorithm for decreasing the computational complexity of the sphere decoder that is used for ML detection of signals on the multi-antenna fading channel. QR factorization with sort decreases the complexity of searching part of the decoder with small increase in the complexity required for preprocessing part of the decoder. Dijkstra’s a...

In wireless communication, the channel state changes repeatedly. In this situation, we select the specification of the Viterbi decoder for the worst case channel state. However, if we select the specification of the Viterbi decoder with such a criterion, the decoder operates inefficiently in the good channel state. In this paper, we propose a specification controllable Viterbi decoder without u...

In this paper, the combination of equalization and turbo decoding is studied. In the iterative decoding of a product code in block turbo coding system, the equalization process is performed within the iteration loop. The present study aims to investigate the decision feedback equalizer (DFE) incorporated in the iterative decoding. Simulation results show that the more severe the channel interfe...