Performance Analysis of PAM-DMT Under Double sided Signal Clipping in IM/DD Based Systems

Implementation of Linearly Pulse Shaped Generalised Frequency Division Multiplexing for Visible Light Communication Systems

“…The BER performance of the proposed LP-DCO-GFDM system is investigated under double sided clipping distortion and compared with CP-DCO-GFDM system using SRRC pulse with a roll-off factor α. For the BER investigation, three different clipping cases as considered; similar to the optical OFDM system report in [15], [16] for Vishay TSHG8200 LED. The three different cases for different average optical power P mean and biasing power P bias with their corresponding clipping levels are presented in Table I.…”

“…Thus, to limit the clipping distortion and to effectively utilize the limited dynamic range, pre-clipping, as shown in Fig. 1, is introduced in the signal according to [15], [16],…”

“…Further, the mean average power of the pre-clipped signal does not exceed P mean in accordance with eye safety limits. Now, the clipping levels are determined as l bot = (P min − P bias )/σ x(n) and l top = (P max − P bias )/σ x(n) similar to optical OFDM systems in [15], [16]. The amount of clipping introduced is controlled by l bot and l top values.…”

“…It can be observed that the received signal in (10) is modeled in terms of unclipped signal x g with an attenuation factor K a . The attenuation factor K a can be calculated similarly to that of DCO-OFDM as in [15], [16]. In (10), the optical path gain coefficient g opt is defined in terms of average irradiance of the photodiode as in [7].…”

“…Here g(l bot , l top ) is a function that defines the average power of the signal and is given as [15], [16]:…”