Patent ID: 8891637

Claim:
An apparatus comprising: at least one processor configured to: determine a number of subcarriers used in a single-carrier frequency division multiplexing (SC-FDM) signal, and a first modulation scheme used to generate the modulation symbols for the SC-FDM signal, the first modulation scheme having an associated order and a peak-to-average ratio (PAR), determine whether the apparatus is operating in transmit power limited conditions based on the determined number of subcarriers, determine whether the apparatus supports a second modulation scheme with an order lower than the order of the first modulation scheme and a PAR lower than the PAR of the first modulation scheme, perform spectral shaping when it is determined that both the apparatus is operating in the transmit power limited conditions and the apparatus does not support the second modulation scheme having the lower order and the lower PAR, the spectral shaping performed by: adjusting at least one parameter of a spectral shaping filter based on one or more characteristics of the SC-FDM signal, the one or more characteristics including at least one of a modulation scheme used to generate the modulation symbols and number of subcarriers used for the SC-FDM signal; and performing the spectral shaping on modulation symbols using the spectral shaping filter to obtain spectrally shaped symbols, bypass performing the spectral shaping when it is determined that either the apparatus is not operating in the transmit power limited conditions or the apparatus supports the second modulation scheme having the lower order and the lower PAR, and generate the SC-FDM signal based on the spectrally shaped symbols or the modulation symbols; and a memory coupled to the at least one processor.