Filter Bank Multicarrier Techniques Research Articles

Investigation of Multiple LED Array Failure on DCO-FBMC Modulation for Indoor Visible Light Communication

Visible light communication (VLC) is a high-speed and power-efficient optical wireless communication method that has gained momentum for data transmission in indoor environments. Indoor VLC systems often use multiple LED arrays to increase the uniformity of brightness and enhance the received energy and the four LED array model is the most commonly used. To suppress the impact of intersymbol interference (ISI) and achieve higher data rates, multicarrier modulation techniques such as orthogonal frequency division multiplexing (OFDM) and filter bank multicarrier (FBMC) have been introduced in VLC systems. The FBMC technique is a promising candidate for the 5G communication system and it has recently been applied to VLC systems. FBMC has several advantages: higher spectrum efficiency, narrower out-of-band radiations and asynchronous transmission. This study investigates the performance of an FBMC-based VLC system when one or more lamps in the multiple LED arrays experience failure. The VLC- FBMC model was implemented using a 4-QAM and 16-QAM format with three various LED array configurations while assuming a line of sight (LOS) model. The LED array model was evaluated based on its ability to achieve good bit error rate (BER) performance, communication quality and high bit rate and meet the required signal-to-noise ratio (SNR). The proposed FBMC model simulation's outcome indicates that the system is still able to transmit data reliably, even in the event of a failure of up to 50% of the lamps. The results indicate that the 2- and 4-lamp models yielded good BER performance, achieving a value of 3.6 × 10−5 and 5.4 × 10−5 respectively. Furthermore, the simulation demonstrated that the optical FBMC-based VLC system attained a high bit rate of 73.2 Mbit/s in the 4-QAM format using the 2-lamp model and a bit rate of 29.3 Mbit/s in 16-QAM format using the 4-lamp model, while maintaining acceptable BER performance.

Spectral Efficient Asymmetrically Clipped Hybrid FBMC for Visible Light Communication

Filter bank multicarrier (FBMC) modulation has shown sufficient potential for wireless communication. A hybrid optical FBMC technique is proposed to improve the spectral efficiency of a visible light communication (VLC) system. In this technique, a hybrid asymmetrically clipped optical offset quadrature amplitude modulation FBMC (HACO-OQAM-FBMC) modulation technique is used. Asymmetrically clipped optical FBMC (ACO-FBMC) is used for odd subcarriers, and pulse amplitude modulation-discrete multitone (PAM-DMT) is used for the even subcarriers. The proposed hybrid scheme uses an intensity modulation/direct detection (IM/DD) channel. It is shown that there is no interference on odd subcarriers using the proposed method and receiver demodulation is similar to that of ACO-FBMC receiver. However, clipping noise of ACO-FBMC falls on PAM-DMT subcarriers, which can be cancelled at receiver processing after estimation. The analytical performance of the proposed technique is compared using parameters, namely, bit error rate (BER), spectral efficiency, computational complexity, and peak to average power ratio (PAPR). It is found that HACO-OQAM-FBMC is more spectral efficient than ACO-FBMC and other OFDM-based techniques.

Interference analysis for asynchrounous OFDM/FBMC based cognitive radio networks over Rayleigh fading channel

In the future fifth generation networked society, devices will suffer from the asynchronous multi-carrier effect which impacts the user’s quality of experience. This paper investigates the timing misalignment effect on interference level in the context of a cognitive radio (CR) network. Our study considers both multicarrier techniques orthogonal frequency division multiplexing (OFDM) and filter bank multicarrier (FBMC). The originality of our paper consists in proposing a simple but accurate analytical model to evaluate our system’s performance in terms of interference level, signal-to-interference-plus-noise ratio and bit error rate. Specifically, two case studies are considered, a single-user case (one primary user and one secondary user) and a multi-user case with exact theoretical expressions of interference level. We had also made a comparison between OFDM and FBMC techniques. The most striking observation to emerge from our results is that the asynchronous interference is inversely propositional to timing offset even for the multi-user case, and that differences in the normalized interference level between the single/multi-user cases is barely perceived for the FBMC technique, proving its efficiency. Our simulations’ results had further strengthened our confidence in the suggested model. It shows that FBMC is best suited for CR networks since it provides BER improvements compared to OFDM.

Filter bank multicarrier with PAM modulation for future wireless systems

The filter bank multicarrier techniques considered for efficient transmission in communication systems generally rely on the offset-QAM modulation, which implies doubling the processing load in transceivers. In contrast, the scheme presented here, based on the complex lapped transform, is running at the same symbol rate as OFDM and it has the perfect reconstruction property. It does not require a cyclic prefix and, in the multi-user context, it provides a high level of spectral separation between users. In addition, a high performance frequency-domain equalizer can be implemented in the receiver in a straightforward manner. Theoretical derivations are completed by simulations for channel equalization. With its reduced computation load and its level of performance, the proposed scheme should strengthen the case of FBMC as an alternative to OFDM for asynchronous access in future wireless networks and cognitive radio.

Filterbank Multicarrier Communications for Underwater Acoustic Channels

This work is motivated by the needs in the doubly dispersive underwater acoustic (UWA) communication channels. We propose and develop the use of filterbank multicarrier (FBMC) technique for communications in the channels of interest. A novel cost function for optimization of the filterbank prototype filter, to achieve a robust performance in doubly dispersive channels, is proposed. A design algorithm that optimizes the proposed cost function is then developed. The developed FBMC technique is compared with the celebrated orthogonal frequency-division multiplexing (OFDM). Our study shows that in doubly dispersive channels, in terms of signal-to-interference-plus-noise ratio (SINR), FBMC outperforms OFDM by several decibels. The theoretical results are validated and confirmed to be applicable to UWA communications, by examining real data from an at-sea experiment (ACOMM10), off the coast of New Jersey in July 2010.

Cosine Modulated and Offset QAM Filter Bank Multicarrier Techniques: A Continuous-Time Prospect

Prior to the discovery of the celebrated orthogonal frequency division multiplexing (OFDM), multicarrier techniques that use analog filter banks were introduced in the 1960s. Moreover, advancements in the design of perfect reconstruction filter banks have led to a number developments in the design of prototype digital filters and polyphase structures for efficient implementations of the filter bank multicarrier (FBMC) systems. The main thrust of this paper is to present a tutorial review of the classical works on FBMC systems and show that some of the more recent developments are, in fact, reinventions of multicarrier techniques that have been developed prior of the era of OFDM. We also review the recent novel developments in the design of FBMC systems that are tuned to cope with fast fading wireless channels.