نتایج جستجو برای: ofdm
تعداد نتایج: 10315 فیلتر نتایج به سال:
Orthogonal frequency division multiplexing with index modulation (OFDM-IM), which transmits information bits via $M$ -ary constellation symbols and indices of the active subcarriers, is a promising OFDM-based multicarrier transmission...
Conventional optical orthogonal frequency division multiplexing (OFDM) schemes, such as adaptively biased OFDM (ABO-OFDM) and hybrid asymmetrically clipped (HACO-OFDM), are unable to tap all the resources of subcarriers only achieve relatively high power efficiency. In this paper, a adaptive bias (HABO-OFDM) scheme for visible light communication (VLC) is proposed improve spectral efficiency HA...
The increasing demand for bandwidth through modern applications and multimedia services has led to high-speed wireless communications. Optical communications (OWC) encourages solutions that provide a higher data rate due the large available. In this paper, performance enhancement approaches are studied simulated visible light communication (VLC) as case study. orthogonal frequency division mult...
In this paper, it is proposed to enhance coherent optical orthogonal frequency-division multiplexing (OFDM) system by using index modulation in terms of bit error rate (BER) and spectral efficiency for different levels the fiber nonlinearity. OFDM with (CO-OFDM-IM), information conveyed not only through activated subcarriers but also indices active subcarrier that are dynamically updated at tra...
This paper proposes a new hybrid orthogonal frequency division multiplexing (OFDM) form termed as DC-biased pulse amplitude modulated optical OFDM (DPO-OFDM) by combining the ideas of existing (DCO-OFDM) and discrete multitone (PAM-DMT). The analysis indicates that required DC-bias for DPO-OFDM-based light fidelity (LiFi) depends on dimming level components DPO-OFDM. bit error rate (BER) perfor...
Abstract Intensity Modulated (IM) optical communication over an LED channel requires the use of a non-negative signal that can also cope with low-pass nature LEDs. For this purpose, dedicated schemes such as Flip-OFDM and Assymetrically Clipped Optical (ACO)-OFDM have been proposed. We derive common mathematical description on which both rely. Exploiting insight, we propose Continuous Phase (CP...
The complementary M-ary orthogonal spreading with frequency division multiplexing (CMOS-OFDM) is an efficient scheme for providing high bit error rate (BER) performance and low peak to mean envelop power ratio (PMEPR) in (HF) communications system. In the CMOS-OFDM, OFDM implemented based on sequence pairs where there issue that one data symbol transmitted through two symbols. this paper, we pr...
Spectrally and energy efficient orthogonal frequency division multiplexing (SEE-OFDM) is an optical OFDM technique based on combining multiple asymmetrically clipped optical OFDM (ACO-OFDM) signals into one OFDM signal. By summing different components together, SEE-OFDM can achieve the same spectral efficiency as DC-biased optical OFDM (DCO-OFDM) without an energy-inefficient DC-bias. This pape...
In this letter, we propose a novel modulation concept which call index and composition (ICM). the proposed concept, use indices of active/deactive codeword elements compositions an integer to encode information. regard, first determine activated elements, then exploit energy levels these identify compositions. We depict practical scheme for using ICM with orthogonal frequency division multiplex...
چکیده : ofdm یک تکنیک مدلاسیون برای ارسال داده با سرعت بالا در کانال محو شدگی چند مسیره است. مهم ترین عاملی که سیستم های siso-ofdm (single-input single output ofdm) را با مشکل مواجه می سازند منابع تداخل می باشد. به منظور حذف تداخل استفاده از آنتن های آرایه ای در گیرنده سیستم های ofdm پیشنهاد شده که simo-ofdm (single-input multiple-output - ofdm) نامیده می شود. یکی از راههای افزایش ظرفیت کانال ...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید