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This paper deals with the MIMO-OFDM technique that candidates with the fourth generation (4G) of the wireless communication systems. This technique can provide high data rate transmission without increasing transmit power and expanding bandwidth. It also it can efficiently use space resources. This paper presents the channel coding assisted STBC-OFDM systems, and employs the Coded Modulation techniques (CM), since the signal bandwidth available for wireless communications is limited. Furthermore, a non-binary Turbo Trellis Coded Modulation (TTCM) decoder-based multidimensional MAP algorithm-assisted G2 STBC-OFDM is designed and implemented. The idea of Non-binary codes has been extended for symbols defined over rings of integers, which outperform binary codes with only a small increase in decoding complexity. The simulation results show that the performance of the TTCM decoding algorithm outperforms the binary decoding methods and is suitable to deal with error-control coding of the STBC-OFDM schemes.
يتعامل هذا البحث مع تقنيات الجيل الرابع لأنظمة الإتصالات اللاسلكية والتي تستطيع أن توفر كماً هائلاً من البيانات المرسلة من غير زيادة في الطاقة المصروفة والحزمة الترددية المستخدمة يستعرض هذا البحث نظرية ترميز القناة اللاسلكية المعتمدة على انظمة (STBC-OFDM) وتوظف تقنية التضمين الترميزي (Coded Modulation), وذلك لمحدودية الحزمات الترددية في الأنظمة اللاسلكية ,وقد تم تصميم وتنفيذ خوارزمية فك ترميز نظام الترميز التوربو(TTCM) غير الثنائي, حيث ان الخوارزمية المصممة وظفت خوارزمية ال (3-D MAP) المستخدمة في الأنظمة الثنائية.ان المفاهيم الأساسية التي تتعامل مع الأنظمة غير الثنائية هي نظرية المجموعات (Groups) ونظرية الحقول (Fields) ونظرية الحلقات (Rings). ان النتائج المستحصلة توضح تفوق أنظمة الأتصالات المعتمدة على نظام الأرقام غير الثنائي على نظيراتها المعتمدة على نظام الأرقام الثنائي.
Turbo codes --- TTCM --- non-binary error correcting codes --- Rings of integers --- MIMO --- OFDM MIMO-OFDM --- STBC --- 4G
In this work, a staircase patch microstrip antenna with slots is proposed to cover the 2G/3G/4G cellular mobile base station bands, when the antenna is excited with a transmission line, creates several modes these modes are composite to obtain a large bandwidth. The proposed antenna operates in the band from 0.86 GHz to 4.78 GHz with an impedance bandwidth of 138%. The use of staircase patch antenna is to achieve more attractive performance such as wider bandwidth, better impedance matching and better radiation. Inserting different slots to the patch of the antenna to enhance the gain and return loss. The gain is obtained ranging from 2.18 dBi to 5.3 dBi. Good radiation efficiencies ranging from 70% to 97% is achieved.
2G/3G/4G mobile base station --- broadband microstrip patch antenna --- staircase patch --- return loss --- voltage standing wave ratio
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