A Spectrally Efficient OFDM-Based Modulation Scheme for Future Wireless Systems

RS Open Journal on Innovative Communication Technologies

2021

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A promising candidate solution for reducing complexity in future wireless systems is the use of non-coherent designs; however, it is very well known in the literature that noncoherent schemes perform worse than their coherent counterparts. To address this longstanding challenging trade-off, we demonstrate and prove in this work the ability of the proposed twodimensional modulation scheme termed as non-coherent orthogonal frequency division multiplexing with subcarrier power modulation and differential phase shift keying in achieving the performance of a coherent design, while reducing complexity. Although the proposed design is non-coherent (i.e., it uses differential phase shift keying and power difference to convey information), it achieves the same bit error rate (BER) performance as conventional OFDM with coherent BPSK. Furthermore, since the proposed scheme employs two-dimensional modulations simultaneously (i.e., DPSK and subcarrier power levels), an additional data stream can be transmitted through the power subcarriers' levels. Thus, the proposed design not only solves the trade-off between coherent and non-coherent modulations in terms of reliability by achieving the same BER, but also provides higher data rates by exploring the power domain as an additional dimension for conveying extra data bits, while maintaining low complexity transceiver design, thus making it very appealing for IoT applications.

Section: B Proposed Design and Contribution Pointsmentioning

confidence: 99%

NC-OFDM-SPM: A Two-Dimensional Non-Coherent Modulation Scheme for Achieving the Coherent Performance of OFDM along with Sending an Additional Data-stream

RS Open Journal on Innovative Communication Technologies

2021

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“…Such a novel noncoherent modulation scheme has great potential in achieving the following merits: 1) reduce complexity, 2) enhance power-saving, and 3) improve the spectral efficiency by at least twice as that offered by conventional OFDM-based schemes. It should be mentioned that OFDM with subcarrier power modulation (OFDM-SPM) [15], [21] is a recently proposed novel modulation scheme that vastly increases the spectral efficiency of the system. This is done by introducing a third dimension through which data can be conveyed.…”

Section: Figure 1 Ofdm-spm Vs Fdm and Ofdmmentioning

confidence: 99%

“…In this new version of OFDM-SPM, the differential phase (through using DPSK as a modulation format) is used jointly with the power of the subcarriers to detect the information data symbols non-coherently, while maintaining the spectral efficiency merits of the original scheme (OFDM-SPM) [15] as well as reducing complexity and signaling overhead. Particularly, OFDM-SPM-DPSK is proposed as a modulation technique to be used for applications requiring high throughput, low complexity, and low power such as those in the domain of IoT.…”

Section: Figure 1 Ofdm-spm Vs Fdm and Ofdmmentioning

confidence: 99%

Non-coherent OFDM-Subcarrier Power Modulation for Low Complexity and High Throughput IoT Applications

RS Open Journal on Innovative Communication Technologies

2020

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Aiming to reduce the transceiver complexity and power consumption of communication systems dedicated to serving future Internet of Things (IoT) applications, researchers have taken many approaches with varying degrees of success. A promising candidate solution that can reduce complexity significantly a n d t h u s a l s o e n h ance p o wer-saving i s t h e u s e o f n o n -coherent m o d ulation-based schemes. Utilizing a non-coherent structure rids the system of any dependency on the knowledge of the phase of the transmitted signal during demodulation. However, although most of the available non-coherent techniques in the literature reduce the complexity of the system, they, unfortunately, suffer from a drawback of some sort, especially in reducing the overall spectral efficiency o f t he s ystem. T o a ddress t his p roblem, w e p ropose a new non-coherent modulation scheme called orthogonal frequency division multiplexing with subcarrier power modulation and differential phase-shift keying (OFDM-SPM-DPSK), as an effective modulation technique for future 6G and beyond systems. The proposed technique has the potential to reduce complexity, enhance power-saving while improving spectral efficiency s i g nificantly, re su lt ing in a sp ec tr al efficiency performance twice that of a conventional OFDM system. Furthermore, receive diversity is implemented through maximal ratio combining to overcome the bit error degradation brought by the adoption of a noncoherent structure. Additionally, the computational complexity is discussed and shown to be as efficient as OFDM, where the proposed scheme does not add further complexity over conventional OFDM.

“…As such, the next generation of 5G communication systems has been proposed. At the forefront of 5G communication and beyond systems, one of the core characteristics aimed to be improved is the data rates it can provide and the spectral efficiency it can achieve . On the other hand, future 6G systems are expected to serve a new set of applications such as haptics, telemedicine, brain‐machine interfaces, mixed reality, virtual reality, augmented reality (AR), and so on, as pointed out in References and , and some other recent studies.…”

Section: Introductionmentioning

confidence: 99%

Orthogonal frequency division multiplexing with subcarrier power modulation for doubling the spectral efficiency of 6G and beyond networks

Hajar

Trans Emerging Tel Tech

2020

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With the emergence of new applications (eg, extended reality [XR] and haptics), which require to be simultaneously served not just with low latency and sufficient reliability, but also with high spectral efficiency, future networks (ie, 6G and beyond) should be capable of meeting this demand by introducing new effective transmission designs. Motivated by this, a novel modulation technique termed as orthogonal frequency division multiplexing with subcarrier power modulation (OFDM-SPM) is proposed for providing highly spectral-efficient data transmission with low-latency and less-complexity for future 6G wireless communication systems. OFDM-SPM utilizes the power of subcarriers in OFDM blocks as a third dimension to convey extra information bits while reducing both complexity and latency compared to conventional schemes. In this article, the concept of OFDM-SPM is introduced and its validity as a future adopted modulation technique is investigated over a wireless multipath Rayleigh fading channel. The proposed system structure is explained, an analytical expression of the bit error rate (BER) is derived, and numerical simulations of BER and throughput performances of OFDM-SPM are carried out. OFDM-SPM is found to greatly enhance the spectral efficiency where it is capable of doubling it. In addition, OFDM-SPM introduces negligible complexity to the system, does not exhibit error propagation, reduces the transmission delay, and decreases the transmission power by half.