transmissions in cable television (CATV) systems
[13,14], and pulse width modulation (PWM)-based
video and audio signal transmissions have been reported
in [15]. However, analog-based modulation schemes
mostly adopted in CATV systems are not ideal for LED-based communications. This is because the luminous
intensity of LEDs does not have a linear characteristic
over the entire injected forward current, becoming
non-linear at higher current levels [16]. This problem
is more acquitted at a higher modulation index or
multiplexed analog-based system as in subcarrier inten-sity modulation. In addition, amplitude modulation-based systems are more vulnerable to noise than digital
schemes.
Nowadays, the digital audio format based on the
Audio Engineering Society-European Broadcasting Union
(AES-EBU) interface is widely used in most media devices
because of certain advantages [17], such as the use of a
single signal to carry both data and clock information and
no DC component as part of the signal power spectral
density. Additionally, using the 24-bit word length makes
it appropriate for professional applications [17,18]. A serial
digital transmission of multi-channel audio signals has
been reported in [19], where an analog multi-channel
audio signal was converted into a digital audio signal
by using a 44.1-kHz pulse code modulation (PCM)
technique