In this paper, we propose an indoor visible light communication (VLC) system which makes use of Walsh precoding and multiple light-emitting diodes (LEDs) at the transmitter for multiplexing the data. The proposed VLC system is based on intensity modulation and uses the notion of spatial modulation for communicating the positive and negative values of the synthesized transmit signal using signal processing technique at the transmitter. We also illustrate the flexibility, ability, and easiness of the system to configure well in a multiuser environment. We have also developed a near-maximum likelihood (ML) detection technique for efficiently decoding the data bits at the receiver. The proposed near-ML reduces the search space involved in ML technique by using the initial ZF solution. The results of the simulation studies illustrate that the proposed technique offers a higher data rate and good bit error rate (BER) performance in indoor VLC environments.

中文翻译：

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使用沃尔什预编码器的新型非直流偏置强度调制室内MIMO-VLC系统

在本文中，我们提出了一种室内可见光通信（VLC）系统，该系统利用沃尔什预编码和发射器处的多个发光二极管（LED）来多路复用数据。所提出的VLC系统基于强度调制，并使用空间调制的概念通过发射机处的信号处理技术传达合成后的发射信号的正值和负值。我们还说明了在多用户环境中进行良好配置的系统的灵活性，功能和易用性。我们还开发了一种接近最大似然（ML）检测技术，用于在接收器处有效地解码数据位。通过使用初始ZF解决方案，提出的Near-ML减少了ML技术中涉及的搜索空间。