We present a new technique for radio frequency (RF) phase-shift amplification based on RF interferometry and demonstrate it in an optical system. A striking feature of this amplifier is that the input phase noise is not amplified together with the input phase signal, so the phase sensitivity improves with higher phase amplification. We also predict that in the case of correlated amplitude noise, the sensitivity is not affected by the amplitude noise. With 600 MHz of modulated light and a phase amplification of 100, we demonstrate a phase resolution of 0.2 mrad, giving a distance resolution of 8 μm. We postulate that nanometric distance resolution can be achieved with sub-gigahertz modulation.

We present in this paper a new equalization method with over 8 dB advantage in the residual ISI compared to the classical results presented by Godard and Shalvi/Weinstein (kurtosis criteria). A systematic derivation is presented for obtaining the conditional expectation for f(x/z) that does not rely on the knowledge of the convolutional noise power nor imposes any restrictions on the probability distribution of the (unobserved) input sequence. We use Edgeworth series which is directly related to quasi moments thus to cumulants, and the Laplace integral method. Although the Edgeworth expansion and the Laplace integral method are well known in non-linear optimal filtering theory, they have not yet been used in the field of blind equalization

Papers dealing with the Ethernet network have shown that the packet delay variation (PDV) is a long range dependency (LRD) process which may be modeled as an fractional Gaussian noise (fGn). In this paper, a closed-form approximated expression is derived for the offset variance valid for multiple precision time protocol (PTP) slaves (IEEE1588 v2) cooperating together in the network. Using this expression, we obtain, when there is a long range dependence in the PDV, the total number of PTP slaves needed to receive the same offset variance as that obtained for the case of white noise PDV.

A nonzero residual intersymbol interference (ISI) causes the symbol error rate (SER) to increase where the achievable SER may not answer any more on the system’s requirements. Recently, a closed‐form approximated expression was derived by the same author for the residual ISI obtained by nonblind adaptive equalizers for the single‐input single‐output (SISO) case. Up to now, there does not exist a closed‐form expression for the residual ISI obtained by nonblind adaptive equalizers for the single‐input multiple‐output (SIMO) case. Furthermore, there does not exist a closed‐form expression for the SER valid for the SISO or SIMO case that takes into account the residual ISI obtained by nonblind adaptive equalizers and is valid for fractional Gaussian noise (fGn) input where the Hurst exponent is in the region of 0.5 ≤ H < 1. In this paper, we derive a closed‐form approximated expression for the residual ISI obtained by nonblind adaptive equalizers for the SIMO case (where SISO is a special case of SIMO), valid for fGn input where the Hurst exponent is in the region of 0.5 ≤ H < 1. Based on this new expression for the residual ISI, a closed‐form approximated expression is obtained for the SER valid for the SIMO and fGn case.