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In recently proposed multiple access techniques such as IDMA and OFDM-IDMA, the user separation is done by user specific interleavers in contrast to conventional CDMA scheme where user separation is assured with user-specific signature sequences. The user specific interleavers must demonstrate minimum probability of collision amongst each other in addition(More)
In recently proposed multiple access techniques like IDMA and OFDM-IDMA, the user separation is done by user specific interleavers in contrast to the conventional CDMA scheme, where user separation is assured with user-specific signature sequences. The user specific interleavers must demonstrate minimum probability of collision amongst each other in(More)
In this paper, we are proposing a novel optical multiple access approach which utilizes the interleaving as only means of user separation. This is different from conventional code division multiple access schemes in which different signature sequences are used to distinguish users. Optical interleave-division multiple-access (OIDMA) scheme inherits the(More)
In this paper, an algorithm is proposed to design maximum possible sets of one dimensional orthogonal codes of given code length 'n', code weight 'w', auto-correlation constraint a λ_a and cross-correlation constraint c λ_c. Each set consists of number of unipolar orthogonal codes up to maximum limit given by Johnson bounds. Here, each of the(More)
The one dimensional unipolar orthogonal codes are employed as signature sequences in spread spectrum modulation schemes like incoherent optical CDMA system. The cardinality or upper bound of code set, containing one dimensional unipolar orthogonal codes of code length 'n' and code weight 'w' and correlation constraint λ, is given by Johnson bounds.(More)
The Interleave-Division Multiple-Access (IDMA) scheme is known for property of orthogonality amongst its user-specific interleavers. The interleavers are, therefore, referred has the core heart of IDMA Transceivers. Now-a-days, the IDMA scheme is being thought as a strongest candidate for radio access in cellular mobile communication systems. It is(More)
The Interleave-Division Multiple-Access (IDMA) scheme is known for property of orthogonality amongst its user-specific interleavers. The interleavers are, therefore, referred has the heart of IDMA Transceivers. In the literature, researchers have proposed Tree Based Interleaver (TBI) which not only reduces the bandwidth requirement in comparison to that(More)
A different and efficient method of image hiding is proposed here. It is based on unitary similarity transformation, involving calculation of eigen values and eigen vectors of a matrix and then transforming it into a diagonal matrix. Only secret image needs to be transformed and is then embedded to the cover image. Inverse transformation can be used to(More)