scholarly journals A Hybrid Single-Carrier/Multicarrier Transmission Scheme with Power Allocation

2007 ◽  
Vol 2008 (1) ◽  
Author(s):  
Danilo Zanatta Filho ◽  
Luc Féty ◽  
Michel Terré
Keyword(s):  
Power Allocation ◽  
Transmission Scheme ◽  
Multicarrier Transmission ◽  
Single Carrier

scholarly journals BER analysis of concatenated levels of encoding in GFDM system using labview

2019 ◽  
Vol 14 (1) ◽  
pp. 77
Author(s):  
Nagarjuna Telagam ◽  
S Lakshmi ◽  
K Nehru
Keyword(s):  
Maximum Likelihood ◽  
Channel Estimation ◽  
Estimation Algorithm ◽  
Front Panel ◽  
Transmission Scheme ◽  
Multicarrier Transmission ◽  
Labview Software ◽  
Ofdm Signal ◽  
Before And After ◽  
Input Side

<p>All the devices are interconnected each other in digital form, for different applications the input data is encoded for error correcting and detecting purpose. The paper describes the transmission of QAM signals with two level encoded stages, i.e. convolutional and hamming coded GFDM system with 256-point IFFT at transmitter and FFT at the receiver using LABVIEW software. GFDM is a non-orthogonal, digital multicarrier transmission scheme which digitally implements the classical filter bank approach. GFDM transmits a block of frame composed by M time slots with K subcarriers. The higher order QAM is used because of transmitting more data but is less reliable when compared to lower order QAM. Based on GFDM specifications for the IEEE 802.11, latest 5G physical layer standards, the coding is provided by ½ rate encoder at the input side, and Maximum Likelihood decoder at the receiver side is used. The standard convolution code (7, [171, 133]), is used as encoder for the GFDM system. The GFDM complex values are displayed in the front panel, along with FFT and power spectrum is plotted for GFDM signal. The array of input bits and output bits are shown with green colour LED’s. The van de Beek algorithm is used at the receiver for maximum likelihood detection acts as convolutional decoder of GFDM signal. Next the signal is subjected to remove cyclic prefix and zero padding and applied to channel estimation algorithm. The un-equalized data and equalized data graph is shown in the front panel, before and after channel estimation VI. With BER VI available in the LABVIEW the data is normalized and its response is plotted with respect to SNR. BER values for different levels of encoders have shown in table for SNR values. This paper concludes the 32.91% improvement in BER for two levels of concatenated codes.Thus the GFDM signal outperforms the OFDM signal interms of BER for series levels of coding using labVIEW software.</p>

Power Allocation in Cyclic Prefixed Single-Carrier Relaying Systems

2011 ◽  
Vol 10 (7) ◽  
pp. 2294-2305 ◽  
Author(s):  
Kyeong Jin Kim ◽  
Theodoros A. Tsiftsis ◽  
H. Vincent Poor
Keyword(s):  
Power Allocation ◽  
Single Carrier ◽  
Relaying Systems

scholarly journals Number of subcarrier filter coefficients in GFDM system: effect on performance

Ingenius ◽  
2019 ◽  
pp. 53-61
Author(s):  
Randy Verdecia Peña ◽  
Humberto Millán Vega
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Modulation Scheme ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Transmission Scheme ◽  
System Effect ◽  
Simple Method ◽  
Multicarrier Transmission ◽  
Prototype Filter

Generalized Frequency Division Multiplexing (GFDM) is a non-orthogonal multicarrier transmission scheme proposed for fifth (5G) and future generation wireless networks. Due to its attractive properties, it has been recently discussed as a candidate waveform for the future wireless communication systems. GFDM is introduced as a generalized form of the widely used Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme and it uses only one cyclic prefix (CP) for a group of symbols. The main focus of this work is to present like impact on the system performance the coefficient quantity of the subcarrier filter. A simple method for the computation of the coefficients of the prototype filter is employed. Besides, it is presented a structure for the GFDM by taking advantage of the arrangement in the modulation matrix. We evaluated the Bit Error Rate (BER) using the receiver models presented in this work. The results showed that the BER is affected according to the coefficients quantity of the prototype filter. Based on the obtained results, the coefficients quantity has a relation with the number of time slots of the GFDM system.

Flexible Multi-Group Single-Carrier Modulation: Subcarrier Mapping and Power Allocation Optimization

2019 ◽  
Vol 67 (3) ◽  
pp. 2002-2014 ◽  
Author(s):  
Yifei Yang ◽  
Shuowen Zhang ◽  
Joni Polili Lie ◽  
Rui Zhang
Keyword(s):  
Power Allocation ◽  
Single Carrier ◽  
Subcarrier Mapping

scholarly journals Quasi-Orthogonal Time Division Multiplexing and Its Performances in Rayleigh Fading Channels

2012 ◽  
Vol 2012 ◽  
pp. 1-5
Author(s):  
Enchang Sun ◽  
Kechu Yi ◽  
Bin Tian ◽  
Dongying Zhang
Keyword(s):  
Fading Channels ◽  
Orthogonal Frequency Division Multiplexing ◽  
Rayleigh Fading ◽  
Carrier Frequency Offset ◽  
Satellite Communications ◽  
Rayleigh Fading Channels ◽  
Transmission Scheme ◽  
Time Division Multiplexing ◽  
Single Carrier ◽  
Time Division

This paper proposes an efficient transmission scheme, Quasi-Orthogonal Time Division Multiplexing (QOTDM), which employs the shift orthogonal property of the pulse function with raised-cosine spectral shape, and the signal waveforms are quasi-orthogonal in time domain. Comparing to orthogonal frequency division multiplexing (OFDM), QOTDM is less sensitive to carrier frequency offset and power amplifier nonlinearities while keeping a similar spectral efficiency with OFDM due to single-carrier characteristics. QOTDM is a suitable consideration for the downlink transmission such as in satellite communications. An upper bound of sample error probability (SER) is derived to evaluate the performance of QOTDM. Comparisons of QOTDM and OFDM in Rayleigh fading channels show that the proposed QOTDM system is better than that of OFDM system in terms of bit error rate (BER) in high Eb/No regions.

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