A New Modified MPPM for High-Speed Wireless Optical Communication Systems

Abstract

Previous work proposed combining multipulse pulse position modulation (MPPM) with pulse amplitude modulation to form multipulse amplitude and position modulation (MPAPM), which is a hybrid modulation that results in an improvement in bandwidth efficiency but a degradation in power efficiency. In this paper, to achieve greater power efficiency and a better data rate, we propose multipulse dual amplitude‐width modulation, based on MPAPM and pulse width modulation. The proposed scheme shows a remarkable improvement in data rate and a 1.5‐dB improvement in power efficiency over MPAPM, while sustaining the bandwidth efficiency. After introducing symbol structure, we present the theoretical expressions of spectral efficiency, the power requirements, and the normalized data rate, as well as the results of comparing the proposed modulation to MPPM and MPAPM.

Recent Trends in Underwater Visible Light Communication (UVLC) Systems

“…The most significant advantage of DPWM is that it solves the narrow pulse problem and has low power efficiency. To control the brightness of the LED in the PPM scheme, a Variable PPM (VPPM) is proposed as in [234]. Furthermore, the VPPM combines PWM and 2-PPM, which control the brightness and data transmission.…”

“…However, an Overlapping Pulse Position Modulation (OPPM) proposed in [236] for improving bandwidth efficiency and high data-rate in MPPM. Utilizing VPPM for data transmission, the system offers complexity; an alternative approach, a Variable Rate Multi-pulse Modulation (VR-MPPM), is investigated to cope with the complex issues as in [234] to achieve both data rate and brightness control simultaneously. Furthermore, an expurgated PPM (E-PPM) modulation scheme is proposed to improve the performance of a peak-power limited M-ary communication system mentioned in Table 11.…”

A Modified Multi-Pulse PPM Modulation based on PWM

“…By normalizing the average the power requirement of MPPM to that of OOK (On Off Keying)we get: find the average power requirement (NPR)of MPDWM normalized to OOK, we multiply (10) by the average N.P.R of MPPM[10]:…”