Performance evaluations of the multi-layers ring network architecture with unicast/multicast function have been done recently by using non-parametric approach. It was claimed that the proposed architecture outperforms the conventional point-to-point multi-layers architecture in terms of the link cost and interface cost. This paper further investigates the impact of the traffic to the nodes in such architecture with unicast capability through optical packet switching simulations. It is found that there are serious packet losses at layer 3 if switches capacity are same at all levels; the required number of wavelengths/optical buffers increases exponentially in order to maintain a given packet loss rate when more layers exist in the architecture. Therefore, it shows that too many layers architecture may affect the networks performances.

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This letter introduces two new OTA-C universal Current mode biquads which offer almost all of the desirable features (expected from a good universal biquad) simultaneously, without any trade-offs. With first OTA removed and the input current source replaced by an input voltage source, both the new circuits can also realise trans-admittance-type universal biquad filters. The workability of the new circuits has been established by SPICE simulation results of their CMOS-implementable versions.

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Although a number of sinusoidal oscillators have been described in earlier literature which employ only a single current feedback op-amp (CFOA) to generate voltage-mode sinusoidal oscillations, any sinusoidal oscillator circuit, which can provide a current-mode output signal explicitly (i.e. from a high output impedance node) while using only a single CFOA, has not been reported till date. This letter describes two such circuits and demonstrates their practicability through experimental results based upon AD844 type IC CFOAs.

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This letter proposes a novel frequency channel blocking (FCB) scheme for millimeter-wave (MMW) entrance networks. In the FCB scheme, any frequency channel is determined to be blocked whether or not, based on not only the network throughput but also the newly defined fairness index. As the results, the FCB scheme yields better throughput and fairness performances with a little increase in computational complexity compared to the conventional scheme.

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A complete analysis of noise in inductively source degenerated CMOS LNA's is presented. One parameter that has great impact on the noise performance of the LNA is L_s. For small L_s the noise of M₁ is dominant, but increasing the L_s causes the output noise power due to other components grow noticeably. We use the MATLAB for simulating the LNA whereas all parasitics are extracted from a 0.35µm CMOS HSPICE technology file. It is supposed the LNA used in the front-end of a prototype UMTS receiver.

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We demonstrate high-speed optical frequency-shift-keying (FSK) transmission over a 95km single-mode fiber (SMF) at 10Gbit/s using a LiNbO₃ optical FSK modulator and an optical interleaver. The measured eye diagrams, bit error rate (BER) performances and optical spectrum indicate the FSK modulation is similar to zero chirp non-return-to-zero (NRZ) on-off-keying (OOK) transmission. Therefore, in view of dispersion tolerance, the FSK modulation can be treated as well as NRZ OOK.

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In this article, mutual relations between Haar and Reed-Muller spectral and functional domains are presented. The new relations apply to any size of the transform matrices in the form of layered vertical and horizontal Kronecker matrices. They allow the direct conversions between Haar and Reed-Muller functions and their corresponding spectra.

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