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Investigation of the Lower Bound of Outage Threshold in Indoor Power-Line Networks
Jaeyoung Shin,Jichai Jeong Institute of Electrical and Electronics Engineers 2016 IEEE Transactions on Power Delivery Vol. No.
<P>We theoretically investigate lower bound of the outage threshold based on channel capacity degradation in indoor power-line networks and its practical applicability to a realistic indoor power-line network existing in practice. We estimate the channel capacity degradations of arbitrary channels in networks with uniformly distributed branches with regular length. The channel capacity degradations are estimated under various network configurations, such as network size, branch characteristics (including the number and length), and loading conditions (including the number, type, impedance, and location). Based on the channel capacity degradation, the lower bounds of the outage threshold of arbitrary channels, which can evaluate the quality of the channels, are given. To evaluate the practical applicability of the simulated results, we compare the lower bounds of the outage threshold between a realistic network and simple networks. It is shown that the Pearson's correlation coefficients between the realistic network and the simple networks are predominantly greater than 0.85 (-value 0.01) in almost all cases, which shows a strong correlation in terms of the outage behavior. Therefore, our investigation enables estimating the outage behavior of a realistic network, without sufficient prior information of the network configuration using a simple network with a similar network configuration.</P>
A Low Power and Wide Variable Gain RF Receiver Front-end for 5.25-㎓ Band
Youngbin Ahn,Jichai Jeong 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
A CMOS front-end with wide variable gain and low power consumption for 5.25 ㎓ band has been designed and simulated with the TSMC 0.18 ㎛ CMOS technology. To obtain wide variable gain range, a p-MOSFET is connected in a shunt configuration for the low noise amplifier (LNA) section. For a mixer, a single balanced and folded structure is employed for the low power consumption. The bias currents of the transconductance and switching stages in the mixer area can be separated without using a current bleeding path. The proposed front-end has a maximum gain of 33 ㏈ with a variable gain range of 25 ㏈. The noise figure and third-order input intercept point (IIP3) are 5.2 ㏈ and -8.5 ㏈m, respectively. For the operating condition, the proposed front-end consumes 7.1 ㎽ at a high gain mode, and 2.6 ㎽ at a low gain mode.
Performance Limitations of DSB Signal Transmissions in Optical SCM/WDM Transmission Systems
Kyoungsoo Kim,Jaehoon Lee,Jichai Jeong 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
We have theoretically investigated the limitations of double-side band (DSB) signal transmissions in SCM/WDM optical transmission systems in terms of crosstalk power and calculated bit-error rate (BER) performance. We also constructed a linear link for the calculation of crosstalk power into each SCM channel to verify the effect of the modulator distortion. Performance limitations of 16 and 32 channels SCM system with a total data rate of 1.6 or 3.2 Gbp/s per wavelength have been studied under various transmission conditions including the impairment factors such as dispersion and fiber nonlinearities.
Janghee Ryu,Jaehoon Lee,Jichai Jeong 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
This paper describes the performances of multiple-input multiple-output (MIMO) space-time adaptive processing (STAP) under homogeneous and nonhomogeneous clutter environments. We consider the presence of jammer signals and the characteristic exponent of a symmetric alpha-stable (SaS) distribution for a nonhomogeneous clutter. To compare the performances according to the clutter type, both the conventional STAP algorithm and the modified eigencanceller (EC) algorithm are used. The modified EC algorithm computes a weight vector adaptively using a number of dominant eigenvalues of the covariance matrix of total interferences. Our simulation results suggest that a number of dominant eigenvalues of the covariance matrix of total interferences in a nonhomogeneous clutter is larger than a homogeneous clutter. In order to maintain a performance of STAP in a nonhomogeneous clutter, we should consider an adaptive method for the computation of a number of dominant eigenvalues.
Jaeyoung Shin,Jaehoon Lee,Jichai Jeong 대한전자공학회 2008 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
This paper describes the time-varying channel responses for an indoor power-line network of a typical apartment in the Republic of Korea. The time-varying channel responses are calculated with considering impedances of appliances and transmission distances according to a time-varying scenario of appliances during a day. Therefore, we can obtain the realistic time-varying channel responses for the indoor power-line network. Our simulation results suggest that the short distance channel responses do not always have the best performance and we should consider every possible situation for the calculation of the channel responses.