Correlation Enhancement of a 4 Element MIMO System

Abstract

The purpose of MIMO (Multiple-Input Multiple-Output) communication systems is to use multiple transmitters and receivers, so multiple antennas, for improved performance over the wireless communication channels. In these systems, antennas play an important role, since the antenna’s features are inherently included in the communication channel between the transmitter and the receiver. Therefore a practical MIMO antenna should have a low signal correlation between the antenna elements. Mutual coupling is a serious problem that is involved in the design of MIMO antennas since it causes a great deterioration in the MIMO system performance; affecting not only the antenna efficiency but also impacts the correlation between the antenna elements. Therefore this report introduces an Asymmetric Coplanar strip (ACS)-fed 4X4 MIMO antenna with an EBG cell structure which gives a hybrid isolation technique between the MIMO elements achieving isolation greater than 30dB. Each of the MIMO system’s antennas operates at three frequencies which are 5GHz, 5.8GHz and 6.3GHz to support different wireless applications. The MIMO system also has an ECC (Envelope Correlation Coefficient) of less than 0.002 and a diversity gain greater than تعد أنظمة الاتصالات متعددة المدخلات والمخرجات بمثابة استخدام متعدد لأجهزة الإرسال والهوائيات المتعددة - لتحسين الأداء من خلال قنوات الاتصال اللاسلكية تلعب الهوائيات دوراً هاماً لأن خصائص الهوائي ضرورية في قنوات الاتصال بين المستقبلات ، لذلك ينبغي أن يكون الهوائي متعدد المدخلات والمخرجات حيث يتسبب في أداء نظام المدخلات المتعددة والمخرجات ، والذي لا يؤثر فقط على كفاءة الهوائي ولكن يؤثر أيضا