Precoder Design for MIMO Visible Light Communications With Decision-Feedback Receivers

Zhai, Yanrong; Tong, Jun; Xi, Jiangtao

doi:10.1109/lpt.2019.2899891

Cited by 7 publications

(9 citation statements)

References 14 publications

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“…From Fig. 4, it can be obviously found that the proposed scheme achieves the best bit transmission accuracy, whereas the method in [16] obtains the largest number of error bits. In addition, when the noise variance becomes smaller, the gap between different schemes gets narrower.…”

Section: Simulation Resultsmentioning

confidence: 97%

“…The capacity depends on actual achieved spectral efficiency as well, which not only relies on the precoder design, spatial diversity scheme, but also is influenced by the noise variance, subchannel gains, and transmission rate. Furthermore, results for comparison with that of schemes in [5], [14], [16] are given, and differences between the strategies are also analyzed.…”

Section: Simulation Resultsmentioning

confidence: 99%

“…Hence, it is vital to allocate power appropriately at the transmitter. In the SVD-based scheme [14] and the geometric mean decomposition (GMD) [16], equal bit loading among all subchannels is applied. This is in contrast to the proposed precoder, in which different amounts of bits are allocated to substreams with given total transmission bits.…”

Section: Simulation Resultsmentioning

confidence: 99%

“…In order to evaluate the effectiveness of the proposed design, we consider a scenario with uncoded transmissions with PAM modulations and a given total transmission rate of B T bits/symbol. The order 2 b k of the PAM modulation for each data stream is determined according to the lower bounds C k of the achievable capacities in (16). This can be done by using the Algorithm 1 given in the table, where b k denotes the transmission rate of the stream k, • denotes taking the integer part of a number, and the vector j records the indexes of the sorted entries.…”

Section: Adaptive Modulationmentioning

confidence: 99%

“…More recently, a SVD-based precoder minimizing the total mean squared error (MSE) was designed in [14], which was not necessarily optimal for BER as the system performance is determined by the subchannel with the least gains. Besides, some other precoder designs for multiple-user downlink transmissions with decision feedback equalizer can also be found in [15], [16].…”

Section: Introductionmentioning

confidence: 99%

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Capacity Maximized Linear Precoder Design for Spatial-Multiplexing MIMO VLC Systems

et al. 2020

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This paper proposes a novel linear precoder design based on the singular value decomposition (SVD) for multi-input multi-output visible light communications (MIMO VLC). We provide an analytical expression on power allocation subject to the function of maximizing the lower bound of capacity according to the optical wireless communication channel model. The expression is rather different from the radio frequency (RF) communications due to the non-negativity of the transmitted signals in VLC. Furthermore, we design an adaptive bit loading scheme for sub-streams with consideration of the tremendous gain difference among subchannels. Performances of the proposed adaptive power and bits allocation strategy are evaluated in two traditional MIMO VLC scenarios, i.e., a practical 2 × 2 indoor scenario and a classical 4 × 4 system that is generated according to the MIMO model. In simulations, the techniques of unipolar M-level pulse amplitude modulation (M-PAM) and spatial-multiplexing (SMP) are employed, and the performance comparison with other SVD-based linear precoders is also given. Simulation results show that the proposed approach can effectively improve the spectral efficiency and guarantee the bit error rate (BER) performance under the same constraints of aggregate optical power budget and non-negativity included by the intensity modulation. It indicates that the strategy of uneven bits and power allocation with full consideration of the ill-conditioned characteristics of subchannels performs better than that based on equal bits transmission in VLC systems. INDEX TERMS Visible light communication, spatial-multiplexing, precoder design, channel capacity.

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Section: Simulation Resultsmentioning

confidence: 97%