... real output signal, complex conjugate symbols are created appropriately and fed into the IFFT, too. Moreover, half of the input of the IFFT around the DC value is filled with zeros to create an OFDM spectrum that avoids interference with second-order nonlinearity after squaring in the photo diode [1 ...

Reducing the Peak to Average Power Ratio of Multicarrier

... into time{domain using the inverse discrete Fourier transform (IDFT). The main advantage of OFDM is that, by introducing a \guard{period" [1] and using dierential encoding, reliable transmission over spectrally shaped channels is possible without any equalization. Unfortunately, because of the stat ...

... into time{domain using the inverse discrete Fourier transform (IDFT). The main advantage of OFDM is that, by introducing a \guard{period" [1] and using dierential encoding, reliable transmission over spectrally shaped channels is possible without any equalization. Unfortunately, because of the stat ...

Spectral Efficiency and Receiver Sensitivity in Direct Detection Optical-OFDM

... Optical transmission systems employing orthogonal frequency division multiplexing (OFDM) have gained considerable research interest because OFDM can combat fiber chromatic dispersion [1,2] and has the capability to use higher level modulation formats to increase spectral efficiency [3]. In direct de ...

... Optical transmission systems employing orthogonal frequency division multiplexing (OFDM) have gained considerable research interest because OFDM can combat fiber chromatic dispersion [1,2] and has the capability to use higher level modulation formats to increase spectral efficiency [3]. In direct de ...

ML Detection with Symbol Estimation for Nonlinear Distortion of OFDM Signals

... subcarriers. As a result, multicarrier systems are more sensitive than the single-carrier systems to the presence of nonlinearities when such a signal is input to a nonlinear amplifier. Due to the large dynamic range of modulated signal, the nonlinear distortion at the power amplifier of transmitter ...

... subcarriers. As a result, multicarrier systems are more sensitive than the single-carrier systems to the presence of nonlinearities when such a signal is input to a nonlinear amplifier. Due to the large dynamic range of modulated signal, the nonlinear distortion at the power amplifier of transmitter ...

Test bed for Selecting Optimum Sequences for

... significantly without additional bandwidth or transmit power by placing multiple antenna elements both on transmitter or receiver, the technology referred to as Multiple Input Multiple Output (MIMO). Increased spectral efficiency through spatial multiplexing, improved link reliability through antenn ...

... significantly without additional bandwidth or transmit power by placing multiple antenna elements both on transmitter or receiver, the technology referred to as Multiple Input Multiple Output (MIMO). Increased spectral efficiency through spatial multiplexing, improved link reliability through antenn ...

Coherent Optical OFDM System or Long-Haul Transmission

... used in optical networks, but spectral efficiency obtained is very less. Recently, many advanced modulation formats in signal amplitude, phase, and polarization has been investigated to increase the capacity of the system. Coherent detection when combined with the advance modulation technique can ea ...

... used in optical networks, but spectral efficiency obtained is very less. Recently, many advanced modulation formats in signal amplitude, phase, and polarization has been investigated to increase the capacity of the system. Coherent detection when combined with the advance modulation technique can ea ...

Timing Synchronization in Cognitive Radio Systems Using Improved

... Television bands (UHF/VHF). Orthogonal Frequency Division Multiplexing (OFDM) being one of the most flexible schemes for the implementation of cognitive radio technique is used in WRAN as a physical layer modulation scheme. In OFDM, several carriers are employed within an allocated spectral bandwidt ...

... Television bands (UHF/VHF). Orthogonal Frequency Division Multiplexing (OFDM) being one of the most flexible schemes for the implementation of cognitive radio technique is used in WRAN as a physical layer modulation scheme. In OFDM, several carriers are employed within an allocated spectral bandwidt ...

PLC G3 Physical Layer Specification Speaker : Jiun

... J = ( j * n_j + i * n_i ) % n I = ( i * m_i + J * m_j ) % m ...

... J = ( j * n_j + i * n_i ) % n I = ( i * m_i + J * m_j ) % m ...

Enhanced fourth-power algorithm for phase estimation with

... In particular, from the average phase θn (k), the superiority of the phase estimation algorithm with separated compensation in accordance to frequency can be clearly observed. The impairments have different effects on the DDO-OFDM signal at various frequencies, and a phase estimation algorithm with ...

... In particular, from the average phase θn (k), the superiority of the phase estimation algorithm with separated compensation in accordance to frequency can be clearly observed. The impairments have different effects on the DDO-OFDM signal at various frequencies, and a phase estimation algorithm with ...

- Leeds Beckett Repository

... of the PLC service. The best suitable modulation technique for PLC system is an Orthogonal Frequency Division Multiplexing (OFDM) [2]. OFDM is a Multi-Carrier modulation scheme in which a single high rate data-stream is divided into multiple low rate data-streams. It is also modulated by using sub-c ...

... of the PLC service. The best suitable modulation technique for PLC system is an Orthogonal Frequency Division Multiplexing (OFDM) [2]. OFDM is a Multi-Carrier modulation scheme in which a single high rate data-stream is divided into multiple low rate data-streams. It is also modulated by using sub-c ...

www.ijecs.in International Journal Of Engineering And Computer Science ISSN:2319-7242

... arrangement of data and null sub-carriers is selected for transmission which gives the least PAPR value. The purpose of shifting the null sub-carriers to positions of data sub-carriers is that the inputs to IFFT changes which in turn gives us different output and hence different PAPR values. B. Impl ...

... arrangement of data and null sub-carriers is selected for transmission which gives the least PAPR value. The purpose of shifting the null sub-carriers to positions of data sub-carriers is that the inputs to IFFT changes which in turn gives us different output and hence different PAPR values. B. Impl ...

投影片 1

... • As discussed before, the received signal consists of multiple copies of the transmitted signal when the channel is under frequency selective fading. • If the fading on different paths are independent, we can combine the contributions from different paths to enhance the total received signal power. ...

... • As discussed before, the received signal consists of multiple copies of the transmitted signal when the channel is under frequency selective fading. • If the fading on different paths are independent, we can combine the contributions from different paths to enhance the total received signal power. ...

(PPT, 328KB)

... 1246MHz with the center frequency 1246MHz + n×0.4375MHz, where n spans the same range as for L1.GLONASS transmitter specs In the original GLONASS design, only obfuscated high-precision signal was broadcast in the L2 band, but starting with GLONASS-M, an additional civil reference signal L2OF is broa ...

... 1246MHz with the center frequency 1246MHz + n×0.4375MHz, where n spans the same range as for L1.GLONASS transmitter specs In the original GLONASS design, only obfuscated high-precision signal was broadcast in the L2 band, but starting with GLONASS-M, an additional civil reference signal L2OF is broa ...