View of FILTER BANK MULTI-CARRIER MODULATION SCHEME FOR 5G COMMUNICATION SYSTEM

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FILTER BANK MULTI-CARRIER MODULATION SCHEME FOR 5G COMMUNICATION SYSTEM

1Ravindra Choudhari, ME Scholar, JEC Jabalpur

2Dr. Prashant Kumar Jain, Prof. Deptt. of ECE, JEC Jabalpur

Abstract:- This paper portrays the parts of Filter Base Multi-Carrier (FBMC) system and features the benefits of new modulation techniques for rising fifth generation Wireless Communication Systems. Orthogonal Frequency Division Multiplexing (OFDM) is a magnificent decision for 4G. some limitations are there with the 4G communication technologies. FBMC are solutions for those limitations like, PAPR, SNR and BER. 4G modulation techniques experience the ill effects of the issue of higher side lobes. Side band lobe is major issue in 4G communication system utilizing OFDM. Current 4G framework depends on the OFDM waveform, which is not equipped for supporting the various applications. The traffic produced by 5G is relied upon to have altogether different qualities and prerequisites when compared with current wireless technology. As result other different access plans are being explored. The best approach to conquer the known restrictions of OFDM is Multicarrier techniques. FBMC are the techniques, which overcomes the limitations of OFDM communication systems. FBMC has lower side loves in comparison to OFDM, which allows a higher utilisation of allocated spectrum. Finally, it is concluded that FBMC performs better in wireless communication system when compared to OFDM. It is noted that FBMC performs better in 5G communication system.

1. INTRODUCTION

Wireless communication system is a major need of the existing world. As it is well known that in such rapidly growing world, fast and efficient communication is required. Modulation is the process of converting data into radio waves by adding information to an electronic or optical carrier signal. A carrier signal is one with a steady waveform like constant height, or amplitude, and frequency.

Multicarrier modulation, is a new step in the field of wireless communication to make the system faster and convenient. Multicarrier modulation is a technique for transmitting data by sending the data over multiple carriers which are normally close spaced.

Multicarrier modulation has several advantages including resilience to interference, resilience to narrow band fading and multipath effects. For fourth generation communication system OFDM

was the best technology but it is not suited for 5G communication system.

This paper compares Filter Bank Multi-Carrier (FBMC) with Orthogonal Frequency Division Multiplexing (OFDM) and highlights the merits of the candidate modulation scheme for Fifth Generation (5G) communication systems. This paper compares Filter Bank Multi-Carrier (FBMC) modulation with generic OFDM modulation. The power spectral density of the FBMC transmit signal highlights the low out-of-band leakage.

FBMC has lower side lobes, this allows a higher utilization of the allocated spectrum, leading to increased spectral efficiency. FBMC offers ways to overcome the known limitations of OFDM of reduced spectral efficiency and strict synchronization requirements. These advantages have led it to being considered as one of the modulation techniques for 5G communication systems.

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Fig.1: Block diagram of FBMC Trans-receiver system

Fig.2: block diagram of OFDM trans receiver system 2. PROPOSED WORK

Filter Bank Multicarrier, FBMC is a form of multicarrier modulation in which the carriers are filtered to provide a more spectrally efficient form of waveform. In this paper FBMC modulation technique is proposed for 5G communication. In comparison to OFDM, FBMC is more effective and efficient, it overcomes the drawbacks of OFDM and thus suitable for fifth generations air communication system.

FBMC is compared with OFDM in terms of following parameters:-

1. Number of FFT points.

2. Guard bands on both sides.

3. Overlapping symbols, one of 2, 3, or 4.

4. Simulation length in symbols.

5. Type of modulation technique (4QAM, 16QAM, 64QAM, 256QAM).

6. SNR in dB

The above parameters are employed in both the modulation systems and simulation has done in MATLAB software environment. Standard values for the above mentioned parameters are as follows:-

Table 1: Parameters used in Proposed work S.

No. Parameters Symbol used for

parameters Standard Value

1 Number of FFT points Num FFT 1024

2 Guard bands on both sides Num Guards 212 3 Overlapping symbols (2, 3 or

4)

K 4

4 Simulation length in symbols Num Symbols 100

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the one used for the zero frequency carrier and is the basis for the other subcarrier filters.

The filters are characterized by the overlapping factor, K which is the number of multicarrier symbols that overlap in the time domain. The prototype filter order can be chosen as 2*K-1 where K = 2, 3, or 4. The current FBMC implementation uses frequency spreading. It uses an N*K length IFFT with symbols overlapped with a delay of N/2, where N is the number of subcarriers.

This design choice makes it easy to analyse FBMC and compare with other modulation methods. The proposed work implements a basic FBMC demodulator and measures the BER for the chosen configuration in the absence of a channel.

The processing includes matched filtering followed by OQAM separation to form the received data symbols. These are de- mapped to bits and the resultant bit error rate is determined. In the presence of a channel, linear multi-tap equalizers may be used to mitigate the effects of frequency-selective fading.

3. RESULTS

Results for the proposed work has been obtained in MATLAB environment, in the form of curves. The result curves are plotted between PSD (in dBW/Hz) and Normalized frequency. The standard values are varied for FBMC and OFDM and analysis is done.

3.1 FBMC Results

Fig.1: num FFT=1024, num Guards=212, K=4, num Symbols=100, bits Per Subcarrier=4QAM, snrdB=12.

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From the above curves of FBMC it is concluded that on varying the value of parameters like Number of FFT points, Guard bands on both sides, Overlapping symbols (2, 3 or 4), Simulation length in symbols and SNR (in dB) the curves changes in terms of PSD and normalised frequency in several manners. Sometimes it is also seen that on some parameters normalised frequency is not changing w.r.t. PSD. It is beneficial when PSD

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3.2 OFDM Results

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Fig.14: num FFT=1024, num Guards=212, K=4, num Symbols=100, bits Per Subcarrier=4QAM, snrdB=24

From the above curves of OFDM it is concluded that on varying the value of parameters like Number of FFT points, Guard bands on both sides, Overlapping symbols (2, 3 or 4), Simulation length in symbols and SNR (in dB) the curves changes in terms of PSD.

When comparing the curves of OFDM and FBMC, it is observed that FBMC has lower side bands and OFDM has higher sidebands. Lower sidebands allow a higher utilization of the allocated network. FBMC is considered more advantageous in comparison to OFDM by offering higher spectral efficiency.

to OFDM by offering higher spectral efficiency. Due to the per subcarrier filtering, it incurs a larger filter delay and also requires OQAM processing, which requires modifications for MIMO processing.

Explore different

system parameter values for the number of sub-bands, number of subcarriers per sub-band, filter length, side-lobe attenuation, and SNR. Sub-band filtering has the benefit of reducing the guards between sub-bands and also reducing the filter length, which makes this scheme attractive for short bursts. PSD shows the strength of variation (in terms of energy)

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