• Title/Summary/Keyword: OFDMA-FDD

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Adjacent Interference Analysis between M-WiMAX OFDMA/TDD and WCDMA FDD System in the 2.6 GHz Band Part I : Adjacent Interference Analysis in SISO System (2.6 GHz 대역에서 M-WiMAX OFDMA/TDD 시스템과 WCDMA FDD 시스템간의 상호 간섭 분석 Part I : SISO 시스템에서의 상호 간섭 분석)

  • Ko, Sang-Jun;Wang, Yu-Peng;Chang, Kyung-Hi
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.6A
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    • pp.573-587
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    • 2007
  • In this paper, we analyze the adjacent interference between WCDMA and M-WiMAX systems in the 2.6GHz Band under the SISO (Single Input Single Output) configuration. The interference scenarios are characterized into 8 scenarios with different victim and interfering links. Among the 8 scenarios, we find that the most performance loss is observed in the scenarios of victim uplink suffering interference from downlink in both systems. Besides, guard band is applied to mitigate the adjacent interference in all the scenarios. Especially, we reveal that M-WiMAX system is much more sensitive to adjacent interference than WCDMA system due to the lower transmission power. In this paper, we consider the worst interference environment, where interferers always transmit with the maximum power, a loose spectrum mask is adapted, and no additional channel fitters are equipped in both systems.

A Synchronous Digital Duplexing Technique for Wireless Transmission in Indoor Environments (옥내 환경에서 무선 전송을 위한 동기식 디지털 이중화 방식)

  • Park, Chang-Hwan;Ko, Yo-Han;Park, Kyung-Won;Jeon, Won-Gi;Paik, Jong-Ho;Lee, Seok-Pil;Cho, Yong-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12C
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    • pp.971-982
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    • 2008
  • In this paper, we propose a new digital duplexing scheme, called SDD(Synchronous Digital Duplexing), which can increase data efficiency and flexibility of resource by transmitting uplink signal and downlink signal simultaneously. In order to transmit uplink data and downlink data simultaneously, the proposed SDD obtains mutual informations between AP(access point) and each SSs(subscriber station), SS and other SSs by mutual ranging procedure. These informations are used for selection of transmission time, decision of CS insertion, setting of CS length, and FFT duration resetting, etc. It is shown that the proposed SDD is appropriate for duplexing scheme in indoor environments over the conventional TDD(Time Division Duplexing) and FDD(Frequency Division Duplexing).