Hybrid adaptive offset O-OFDM visible light communication system and method

Abstract

The invention discloses a hybrid self-adaptive offset O-OFDM visible light communication system and method, which are characterized in that at a transmitting end, PAM and QAM visible light communication modulation methods are mixed, original data are grouped, and three groups of data are respectively transmitted and modulated by adopting different subcarriers, so that the spectrum utilization rate of the system is improved; when the non-negativity of the signal is ensured, the self-adaptive bias is added, so that the requirement of the non-negativity of the signal can be met, and noise generated by introducing the self-adaptive bias does not cause interference on signal demodulation in two modulation modes; according to the system and the method provided by the invention, as the receiving end is not influenced by clipping noise and adaptive bias noise, de-noising processing does not need to be carried out on the signal, so that the complexity of the system is reduced. According to the technical scheme of the invention, compared with the peak-to-average power ratio (PAPR) of a traditional visible light communication modulation method, the method also has a remarkable advantage, and the power efficiency of the system is also improved.

Description

technical field [0001] The invention relates to a visible light communication system and method of O-OFDM with hybrid self-adaptive bias, and belongs to the technical field of wireless optical communication. Background technique [0002] Visible light communication combines LED technology with information transmission, does not occupy radio frequency spectrum resources, and can provide high-speed and large-capacity communication methods for indoor wireless communication networks. Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation technology with high spectrum efficiency, which can effectively resist multipath fading and inter-signal interference in the wireless transmission process, and is simple to implement, and has been widely used in in visible light communication. [0003] Visible light communication systems usually use intensity modulation direct detection (IM / DD), so visible light communication can only transmit positive real signals. In...

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Problems solved by technology

[0005] In order to solve the problems of low spectrum utilization, high peak-to-average power ratio (PAPR) and high system complexity in the prior art of visible light communication, the present invention proposes a hybrid adaptive bias optical orthogonal frequency division The visible light communication system and method of the multiplexing technology (O-OFDM) can not only increase the spectrum utilization rate, but also reduce the peak-to-average power ratio (PAPR), reduce system complexity, and improve power efficiency

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