Performance Comparison of MDFT Filter Bank with OFDM in Multi-Carrier Systems

2014 ◽  
Vol 926-930 ◽  
pp. 1822-1826
Author(s):  
Ling Zhuang ◽  
Ju Ge ◽  
Guang Yu Wang ◽  
Kai Shao
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Average Power ◽  
Symbol Error Rate ◽  
Performance Comparison ◽  
Frequency Division ◽  
System Prototype ◽  
Detailed Derivation ◽  
Carrier Systems

Based on the filter bank, the theory of multi-carrier modulation using Orthogonal Frequency Division Multiplexing (OFDM) and Modified Discrete Fourier Transform (MDFT) filter bank has been discussed and the detailed derivation process has been given. Following these discussions, the actual implementation of MDFT filter bank in multi-carrier modulation systems has been discussed, and then the comparison of their prototype functions, Peak to Average Power Ratio (PAPR) and Symbol Error Rate (SER) are drawn. Experimental results demonstrate that compared with the OFDM system, prototype functions of MDFT have obvious advantage in spectrum leakage. In terms of PAPR, they have similar performance. Whether using QPSK or 16QAM modulation, MDFT is superior to OFDM in symbol error rate as a whole and with increasing of filter length L, the advantage becomes more and more apparent.

scholarly journals Spectral Efficiency of FBMC Over OFDM System

2019 ◽  
Vol 9 (2S3) ◽  
pp. 235-237
Keyword(s):  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Average Power ◽  
Primary Objective ◽  
Mobile Environments ◽  
Frequency Division ◽  
Doppler Shifts ◽  
Wireless Broadband ◽  
High Spectral Efficiency

Significant wireless broadband technology used in various cellular standards is Orthogonal Frequency Division Multiplexing (OFDM) which will make use of Multi Carrier Modulated (MCM) systems. Even though OFDM has numerous advantages, it is hard to employ OFDM for complex networks. It is very hard to establish synchronization in mobile environments as it is difficult to predict the Doppler shifts of different users, which results in inter carrier interference (ICI). Further, filters associated with OFDM carrier have comparatively large sidebands which outcomes in Out of Band (OOB) radiations. Insufficient spectral usage is provided by CP-OFDM by using more guard band. So the problems caused by traditional OFDM/CP-OFDM can be answered by employing a new system termed as Filter Bank Multi Carrier (FBMC) System. It is a form of MCM and it can be considered as an advanced cyclic-prefix (CP-OFDM). In OFDM, whole band gets filtered while in FBMC, each sub carrier band is independently filtered. The primary objective of this work is to relate the performance of 5G modulation technique such as FBMC against OFDM and to suggest an ideal waveform for 5G communication in regard to high spectral efficiency, spectral density, BER and less Peak to Average Power Ratio (PAPR).

scholarly journals APR Reduction Technique based on OFDM Pilot Filter Bank Limiting for Satellite Mobile Communications

2018 ◽  
Vol 246 ◽  
pp. 03002
Author(s):  
Tianfang Dai
Keyword(s):  
Mobile Communications ◽  
Bit Error Rate ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Hardware Implementation ◽  
Reduction Technique ◽  
Papr Reduction ◽  
Frequency Division Multiplexing ◽  
Frequency Division

Combined with OFDM (Orthogonal Frequency Division Multiplexing), satellite mobile communications will effectively achieve on-demand communication in areas with an ultra-low density of users. With OFDM multiple access optimization, the bandwidth utilization efficiency can be increased by 5 to 10 times. However, satellites are power-constrained systems, so higher PAPR requires greater power backoff, resulting in a decline in satellite transmission capacity. To use OFDM technology in satellites, there are problems such as reduced transmission capacity resulted from high PAPR, complication of lowering PAPR, and difficulty in hardware implementation. In order to deal with the problem of high bit error rate and hardware implementation difficulties in PAPR reduction technique of non-orthogonal frequency division multiplexing, this paper proposes a limiting PAPR reduction technique with OFDM pilot filter banks for satellite mobile communications. Firstly, the applicability of OFDM in satellite mobile communications is analyzed, and the influence of high PAPR on satellite power utilization and the influence of frequency shift sensitivity on inter-satellite communication interference are obtained. Then design the PAPR reduction technique based on the pilot filter bank. By setting the tunable filter bank to the pilot, the sideband power suppression in the OFDM frequency domain is realized, and the PAPR of the OFDM signal is reduced. Finally, the experimental results show that the PAPR performance is improved by 3dB without reducing the bit error rate.

scholarly journals PERFORMANCE EVALUATION OF FILTER BANK MULTI-CARRIER MODULATION IN MULTIPATH FADING CHANNELS

2021 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Ali A. Abdulhussein ◽  
Hikmat N. Abdullah
Keyword(s):  
Performance Evaluation ◽  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Filter Bank ◽  
Multipath Fading ◽  
Symbol Error Rate ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Multipath Fading Channels ◽  
5G Technologies

Filter Bank Multi-Carrier (FBMC) modulation is one of the most significant enablers for future 5G technologies. It is a modulation technique for resolving inter-carrier and inter-symbol interference using two possible methods: Frequency Spreading (FS) and Poly Phase (PP) implementation. Cyclic prefixes are used in OFDM for signal robustness, but they have some disadvantages in orthogonal frequency division multiplexing. FBMC is used to solve the disadvantages of OFDM and save a bandwidth.  In this paper, performance comparisons in terms of symbol error rate between OFDM and FBMC systems in AWGN and multipath fading channels are presented. The obtained results show that FBMC over performs OFDM in multipath fading channels and the improvement margin is increased as the number of subcarriers decreased.

scholarly journals Algorithm for Decreasing the Large Peak to Average Power Ratio in Mimo-Ofdm

2020 ◽  
Vol 8 (6) ◽  
pp. 2272-2276
Keyword(s):  
Error Rate ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Average Power ◽  
Symbol Error Rate ◽  
Power Ratio ◽  
Mapping Algorithm ◽  
Mimo Ofdm ◽  
Large Maximum

Every personal want to use high speed communication system but bandwidth is limited and users are unlimited in that case some of technologies are use for improving speed. One of the best technology called multiple inputs multiple outputs orthogonal frequency division multiplexing. Which provides very fast communication system but drawback of this technique is large maximum to average power ratio, these reduce efficiency of power amplifier. In this article developed new algorithm, for reduction of large maximum to average power ratio and improve bit or symbol error rate in MIMO-OFDM system. Proposed technique, called filter companding selected mapping algorithm technique (FC-SLM) to reduce PAPR using filtering and companding concept. In this techniques, after modulation of input data are converted into serial to parallel steam, phase mapping of all data from 0 to 360 degrees and perform IFFT operation, calculate PAPR and pass through desire range of filter and select minimum PAPR then perform companding and transmitted through an antenna. This scheme is reduce 2.3 dB PAPR and improve bit or symbol error rate. This is one of the most excellent promising techniques for next generation (5-G) communication system.

scholarly journals SLM Technique to Reduce PAPR and Improve BER in OFDM Systems

2021 ◽  
Vol 9 (VI) ◽  
pp. 5138-5143
Author(s):  
N. Sai Santhosh
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Rate Distortion ◽  
Estimation Accuracy ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Time Frequency

Through the combined use of multiple input, multiple output, and orthogonal frequency division multiplexing technologies, mankind has achieved a huge leap in the data rate of gigabit per second with the birth of 5G wireless technology. With frequency selective fading, multiple (OFDM MIMO) is possible. One of its most important performance concerns is PAPR (Peak-to-Average Power Ratio), which renders OFDM particularly vulnerable to harmonic distortion, reducing channel estimation accuracy and resulting in a lower bit error rate (BER). We propose a selective codeword shift mapping method for the MIMO-OFDM system (SCS-SLM). It lowers the PAPR and causes the power amplifier to operate in the non-linear area, resulting in intermodulation between sub-carriers, signal constellation, bit error rate distortion, as well as enhanced system performance. Furthermore, employing space-time-frequency block code (STFBC OFDM) orthogonal frequency division multiplexing might improve BER performance. This paper mentions a useful strategy for minimizing the PAPR, which is Selective Mapping. In addition, the bit error rate performance and, as a result, the process complexity for this system is discussed. In addition to the above-mentioned analysis, a thorough analysis of the mutual independence of the alternative OFDM signals generated using this technique is also discussed. Furthermore, this new approach has the important benefit of removing the extra bits on the side of the transmitted OFDM signal.

scholarly journals Advantages of Spectrally Efficient Frequency Division Multiplexing Over Orthogonal Frequency Division Multiplexing

2020 ◽  
Vol 9 (8) ◽  
pp. 238-244
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Sphere Decoder ◽  
Symbol Rate ◽  
Transmission Length ◽  
Spectrally Efficient ◽  
The Impact

An analysis on Spectrally Efficient Frequency Division Multiplexing (SEFDM) is contrast with Orthogonal Frequency Division Multiplexing (OFDM) considering the impact on Peak to Average Power Ratio (PAPR) and nonlinearities within fibre. With respect to OFDM the sub-carriers in SEFDM signals are compressed adjacent to each other at a rate of frequency lesser than the symbol rate. At the receiver end we have utilized the Sphere Decoder which is used to recover the data to remunerate the Interference created by the compressed signals (ICI) faced in the system. This research shows the advantages by using SEFDM and evaluates its achievement. PAPR. when compared with OFDM, while effects of non-linear fibres are considered. The use of various formats of modulation going from 4-QAM to 32-QAM, shows that the SEFDM signals have a noteworthy increment in the transmission length with respect to ordinary signals.

scholarly journals AN EFFICIENT METHOD FOR PAPR REDUCTION IN OFDM SYSTEMS WITH REDUCED COMPLEXITY

2013 ◽  
pp. 96-100
Author(s):  
PRITANJALI KUMARI ◽  
US TRIAR
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
High Peak ◽  
Papr Reduction ◽  
Power Calculation ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Reduced Complexity

Orthogonal Frequency Division Multiplexing (OFDM), widely used in digital wireless communication, has a major drawback of high Peak to Average Power Ratio (PAPR). A reduced complexity partial transmit sequence (PTS) scheme has been proposed to solve high peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) system. In the proposed PTS scheme, a function is generated by summing the power of time domain samples at time ‘n’ in each sub blocks, known as “Hn”.Only those samples, having Hn greater than or equal to a preset threshold value (αT) are used for peak power calculation during the process of selecting a candidate signal with the lowest PAPR for transmission. As compared to conventional PTS scheme, the proposed scheme achieves almost the same PAPR reduction performance with much lower computational complexity.

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