اختلالات مدوله شده با طیف گسترده
Abstract
I. Introduction
II. Communication Channel and EMI Modelling
III. EMI-Induced Channel Capacity Loss
IV. Validation
V. Discussion
Authors
Figures
References
Abstract
In this paper, the effects of random spread spectrum (SS) electromagnetic interference (EMI) on digital communications are addressed. For this purpose, the influence of EMI on a communication channel is described in the framework of information theory in terms of an equivalent channel capacity loss, which is analytically predicted and validated by experimental results. The EMI-induced channel capacity loss for nonmodulated and SS-modulated interference generated by a switching-mode DC-DC power converter are then evaluated for different EMI and channel characteristics so that to compare different scenarios of practical interest.
Introduction
Electromagnetic interference (EMI) from switching-mode power converters and digital equipment can be easily coupled to susceptible communication blocks within the same module or integrated circuit, due to parasitic coupling through the power distribution network, through the package and/or through the silicon substrate and can be a threat to the operation of present-day information and communication technology (ICT) electronic systems inducing malfunctions ranging from the degradation of the bit error rate (BER) up to the complete failures [1]–[6]. As a consequence, EMI needs to be carefully controlled in the very first design stages at architectural and integrated circuit level to assure the proper operation of complex systems with no penalty in terms of costs, time-tomarket and performance, and also in order to meet the more and more stringent Electromagnetic Compatibility (EMC) regulations [7]–[10]. In this context, several techniques have been devised to address EMI at circuit and architectural level [11]–[14]. In particular, the techniques based on the frequency modulation of critical switching signals, generally known as SpreadSpectrum (SS) techniques, have been extensively proposed as simple, low cost solutions to mitigate EMC problems and are widely employed in practice [13]. Spread-spectrum techniques have been introduced as a mean to reduce the peak value of EMI spectrum since the middle of 1990s with specific reference to switching power converters and digital clocked equipment [15], [16].