End-to-end learning systems are conceived for Orthogonal Frequency Division Multiplexing (OFDM)-aided optical Intensity Modulation paired with Direct Detection (IM/DD) communications relying on the Autoencoder (AE) architecture in deep learning. We first propose an AE-aided Layered ACO-OFDM (LACO-OFDM) scheme, termed as LACONet, exploiting increased bandwidth efficiency of LACO-OFDM. LACONet em...

We propose and experimentally demonstrate a new scheme to reduce the energy consumption of optical network units (ONUs) in orthogonal frequency division multiplexing passive optical networks (OFDM PONs) by using time-domain interleaved OFDM (TI-OFDM) technique. In a conventional OFDM PON, each ONU has to process the complete downstream broadcast OFDM signal with a high sampling rate and a large...

Orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (TDM) bridges the conventional OFDM and single carrier (SC) transmission. For a coded OFDM/TDM system with frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion in a frequency-selective fading channel, there is a trade-off between coding gain and frequency diversity effec...

-Multi-carrier modulation has been used in many wired and wireless communications. It was used in many military high frequency radios, audio-video broad casting and DSL. Multi-carrier modulation can be digitally implemented using Orthogonal Frequency Division Multiplexing (OFDM).Inter symbol Interference can be completely avoided in OFDM by inserting cyclic prefixes. In OFDM wide band channel b...

Orthogonal frequency division multiplexing (OFDM) is a parallel transmission method, where single data stream is separated into a number of lower rate subcarriers, and each carrier is orthogonal to all other carriers. One of the main problems for OFDM system is Carrier frequency offset (CFO). OFDM is sensitive to CFO, which spoils the orthogonality between the sub-carriers, and cause Inter-carr...

Multicarrier transmission system such as Orthogonal Frequency Division Multiplexing (OFDM) is a promising technique for high bit rate transmission in wireless communication systems. OFDM is a spectrally efficient modulation technique that can achieve high speed data transmission over multipath fading channels without the need for powerful equalization techniques. A major drawback of OFDM is the...

In the literature, the bounds of the peak to average power ratio (PAPR) are generalized to both complex-valued and real-valued orthogonal frequency division multiplexing (OFDM) signals. In fact, these bounds are accurately bounding the PAPR distribution of complex-valued OFDM signals only. In this paper, we derive accurate PAPR bounds of real-valued OFDM signals and show that bounds of complex-...

In this letter, a low-complexity receiver (Rx) is proposed for hybrid asymmetrically clipped optical orthogonal frequency division multiplexing (HACO-OFDM). Owing to the special time-domain property of HACO-OFDM, overlaid OFDM (ACO-OFDM) and pulse-amplitude-modulated discrete multitoned (PAM-DMT) signals can be distinguished in time domain reduce its computational complexity. Besides, near-opti...

Recent advances in wireless communication systems have increased the throughout over wireless channels. Unipolar communications systems can transmit information using only real and positive signals. We consider two unipolar OFDM techniques such as FLIP-OFDM and ACO-OFDM. This includes a variety of physical channels ranging from optical, to RF wireless using amplitude modulation with non-coheren...

This paper discusses an adaptive modulation technique combined with space-frequency block coded OFDM(SFBC OFDM) over frequency selective channels and evaluates the performance in terms of the outdated channel state information(CSI) in mobile environments. This paper employs the Alamouti’s diversity scheme in multiple input multiple output OFDM (MIMO OFDM) and an adaptive modulation with enhance...