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

Practical designs for out-of-band emission suppression and adjacent channel interference rejection for orthogonal frequency division multiplexing-based cognitive radios

“…In order to distinguish these two precoded-OFDM (P-OFDM), they are named as spectral precoded (SP)-OFDM and PAPR precoded (PP)-OFDM in this paper. Our research in [16] shows that these two precoding techniques can be combined to achieve satisfactory spectral containments and PAPR performance simultaneously. (The spectrum containment of a waveform is satisfactory when the stopband attenuation is larger than 55 dB, as in the spectral mask requirement of Federal Communications Commission (FCC) TV white space when the effective isotropic radiated power is +36 dBm [18].)…”

“…However, unlike windowing, it is less sensitive to the TO between PU and SUs when it is used to suppress OOBE of OFDM signal and has high complexity when the spectrum is non-contiguous or dynamically changing. For the frequency-domain example, spectral precoding approach is very efficient for reducing OOBE and can be easily extended to reduce PAPR simultaneously by combining with PAPR precoding [16]. However, it suffers spectral efficiency loss and has high computational complexity when the number of subcarriers is large or when the spectrum is non-contiguous or dynamically changing.…”

OFDM for Cognitive Radios: An overview Present Solutions and Future Directions

“…In the previous sections, we have discussed that precoding techniques have shown good performance in suppressing OOB power and in reducing PAPR separately. However, to the best of our knowledge, very little work [39], [40] exists on the design of precoding techniques for joint reduction of PAPR and OOB power. In [39], three precoding designs have been presented for joint suppression of PAPR and OOB power.…”

“…However, to the best of our knowledge, very little work [39], [40] exists on the design of precoding techniques for joint reduction of PAPR and OOB power. In [39], three precoding designs have been presented for joint suppression of PAPR and OOB power. It has been shown that all these designs show same OOB power reduction as that of SVD precoding approach.…”

Approach to suppress out‐of‐band emission for dual pseudo noise padded time‐domain synchronous‐orthogonal frequency division multiplexing systems

“…Unfortunately, such SRRC with a very small roll‐factor is difficult to implement in hardware [4]. Moreover, because of the PN padded structure, the state‐of‐the‐art out‐of‐band suppression approaches for CP/ZP‐OFDM cannot be directly applied for the TDS‐OFDM systems [18–22].…”