Precoder designs for jointly suppressing out-of-band emission and peak-to-average power ratio in an orthogonal frequency division multiplexing system

2014 ◽  
Vol 8 (10) ◽  
pp. 1705-1713 ◽  
Author(s):  
Juan Fang ◽  
I-Tai Lu
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Shiv Om Tiwari ◽  
Rajeev Paulus

AbstractDue to the evolution of mobile phone technology which enables the use of Internet, the demand for data rates has increased tremendously. Therefore, current 4G-LTE (long-term evolution) technology needs to be replaced in near future. Hence, currently possible solutions for 5G technology are heavily investigated. Generalized frequency division multiplexing (GFDM) is one such technique which is based on multi-carrier filters and uses time-frequency structure to optimize delay and out-of-band emission (OOB). Still GFDM is very much similar to orthogonal frequency division multiplexing (OFDM) with much improved spectral and peak-to-average power ratio (PAPR) performance. This paper presents a detailed description of GFDM technique, along-with its comparison to OFDM method. This paper further investigates the non-linear companding scheme which can be used to further reduce PAPR. Simulation results are presented to obtain (Power Spectral Density) PSD and PAPR performance.


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.


Author(s):  
PRITANJALI KUMARI ◽  
US TRIAR

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.


Sign in / Sign up

Export Citation Format

Share Document