Everything about 5G Modulation Techniques

The fifth-generation (5G) networks are poised to adhere to a standard that demands reduced latency, high data rates, and optimized spectrum utilization, and the modulation technique used in this network generation plays an important role.

Orthogonal Frequency Division Multiplexing (OFDM) is a prevalent modulation technique employed in 4G. However, OFDM’s high peak-to-average power ratios lead to inefficient power amplifier usage and increased battery consumption. Also, OFDM has too many out-of-band side lobes, which diminish its spectral efficiency and contribute to inter-symbol interference.

Fortunately, the advanced modulation techniques in 5G have largely addressed OFDM’s limitations. These 5G modulation techniques include Generalized Frequency Division Multiplexing (GFDM), Filtered-OFDM (f-OFDM), Universal Filtered Multi-Carrier (UFMC), and Filter Bank Multi-Carrier (FBMC).

With the help of pulse shaping, sub-band filtering, and sophisticated signal processing, these modulation techniques surpass the capabilities of 4G modulation techniques.

This post delves into 5G modulation techniques, shedding light on how these advancements have elevated the wireless communication system through innovative modulation technology.

5G Modulation Techniques

The modulation techniques used in 5G include OFDM, GFDM, f-OFDM, UFMC and FBMC. Though OFDM were more prevalent in 4G modulation, it was still utilized in 5G modulation and it is even the building bock for other advanced 5G modulation techniques.

1. OFDM (Orthogonal Frequency Division Multiplexing): OFDM is a fundamental modulation technique used in both 4G and 5G networks. It divides a high-data-rate signal into multiple lower-data-rate subcarriers, and this help in efficient spectrum utilization and mitigation of multipath fading. OFDM serves as the building block for all other 5G modulation techniques that we will be discussing in this post.
2. Generalized Frequency Division Multiplexing (GFDM): GFDM stands as a 5G modulation techniques intended to address OFDM’s shortcomings. GFDM utilizes a filter bank structure where individual subcarriers undergo independent filtering. This curtails out-of-band emissions and ensures superior spectral containment. GFDM aims to provide a lower Peak-to-Average Power Ratio (PAPR), reduced sidelobes, and enhanced efficiency compared to OFDM.
3. Filtered-OFDM (f-OFDM): Filtered-OFDM represents another iteration of traditional OFDM. It integrates subcarrier filtering to suppress sidelobes and enhance spectral containment. This attenuation of interference among neighboring subcarriers bolsters overall spectral efficiency. F-OFDM outperforms standard OFDM in terms of sidelobe leakage.
4. Universal Filtered Multi-Carrier (UFMC): UFMC, a 5G modulation techniques, combines filtering with multi-carrier transmission. The frequency spectrum is segmented into sub-bands, each with its own filter. This approach facilitates efficient spectrum usage, leading to diminished out-of-band emissions. UFMC is also designed for adaptability through variable sub-band widths, which makes it suitable for diverse communication scenarios.
5. Filter Bank Multi-Carrier (FBMC): FBMC is akin to OFDM but distinguishes itself by subjecting subcarriers to filters that suppress signal sidelobes, and this results in strict band limitation. FBMC works with Quadrature Amplitude Modulation (QAM) or offset QAM (OQAM) modulation formats. However, for optimal spectral efficiency, FBMC works with OQAM to attain real-domain orthogonality across time and frequency domains. With the aid of generalized pulse shaping filters, FBMC surmounts OFDM’s limitations, resulting in localized subchannels in both frequency and time domains. The transmitter-side filter bank is known as the synthesis filter bank, while the receiver-side filter bank is the analysis filter bank

Spectral Efficiency: FBMC vs. UFMC

Spectral efficiency, which measures information transmission over a given bandwidth, is an important factor in evaluating modulation techniques.

FBMC has higher spectral efficiency for extended burst durations, while UFMC is better for shorter burst durations. This means that FBMC suits applications demanding higher data rates, while UFMC is optimal for lower data rates with stringent latency requirements.

Power Spectral Density: FBMC vs. UFMC

Power Spectral Density (PSD) is another important metric gauging frequency spectrum utilization efficiency.

FBMC outshines UFMC in PSD characteristics, attributed to reduced out-of-band spectral leakage. This aspect of FBMC mitigates inter-symbol interference and inter-carrier interference, making it a preferred choice for 5G networks.

Conclusion

The primary objective of 5G modulation techniques is to align with the standards of the fifth-generation network, which include reduced latency, high data rates, and efficient spectrum utilization.

Traditional modulation techniques like OFDM fall short of addressing these benchmarks, consequently yielding ground to innovative alternatives like GFDM, f-OFDM, UFMC, and FBMC.

This post highlighted the strengths and weaknesses of each modulation technique in terms of spectral efficiency and power spectral density.

UFMC excels in spectral efficiency for brief burst durations, which makes it suitable for such applications. On the other hand, FBMC suits communication systems that need prolonged burst durations.

Regarding PSD, FBMC exhibits lower out-of-band spectral leakage, translating to higher spectral density. Based on these findings, FBMC is a more fitting choice for 5G systems, effectively minimizing inter-symbol interference and inter-carrier interference.

Also Read;

• 1G modulation technique
• 2G modulation technique
• 3G modulation technique
• 4G modulation technique