Orthogonal frequency division multiplexing with subcarrier number modulation (OFDM-SNM) has been recently proposed to improve the spectral efficiency (SE) of traditional OFDM system. In this paper, we propose a joint-mapping OFDM-SNM (JM-OFDM-SNM) scheme transmit signal vector constant length information bits by jointly considering activation patterns and constellation symbols. A low-complexity...

one of the limitations of orthogonal frequency division multiplexing (ofdm) in many applications is its sensitivity to frequency shifts, errors normally referred to as carrier frequency offset (cfo). although, this small offset is negligible in conventional single carrier communication systems, it is a severe problem in the ofdm systems. because, the carriers in ofdm are inherently closely spac...

OFDM-IM (İndeks Modülasyonlu Dikgen Frekans Bölmeli Çoğullama), 5G (Beşinci Nesil) ve ötesi iletişim sistemleri için aday iletim tekniklerinden birisi olarak son yıllarda üzerinde birçok çalışma gerçekleştirilmiştir. OFDM-IM'nin spektral verimliliğinin artırılması amacıyla geliştirilen OFDM-AIM (Tüm İndeks OFDM) tekniğinde, boş alt-taşıyıcıların bulunduğu OFDM-IM'den farklı tüm alt-taşıyıcılar ...

A novel spectrally efficient modified asymmetrically and symmetrically clipped optical (mASCO)-OFDM for intensity modulated direct detection (IM/DD) systems is presented. The conventional ASCO-OFDM use two frames to transmit the (ACO)-OFDM (SCO)-OFDM system. proposed mASCO-OFDM system replaces frame SCO-OFDM by a single SCO (mSCO)-OFDM. mSCO-OFDM clips data on only one side of symmetry performs...

The performance of Low-Density Parity-Check (LDPC)-coded Orthogonal Frequency Division Multiplexing (OFDM) is investigated over turbulence channels in underwater wireless optical communications (UWOC). relation between the bit error ratio (BER) and parameters such as scintillation coefficient, signal-to-noise (SNR), length LDPC code, order OFDM quantified by simulation. Results show that while ...

Non-orthogonal multiple access (NOMA) is deemed to be a prospective technology of the next generation. However, in visible light communication (VLC), when advanced hybrid optical orthogonal frequency division multiplexing (O-OFDM), such as asymmetrically clipped O-OFDM (HACO-OFDM), combined with NOMA, error propagation induced, which degrades system performance. Therefore, novel reconstructed O...