Linear Precoder Design for PAPR Reduction of GFDM Signals Using Gradient Descent Methods

This paper addresses linear precoder design for Peak-to-Average Power Ratio (PARP) reduction of Generalized Frequency Division Multiplexing (GFDM). A general framework, which is composed of four different scenarios and utilizes Gradient-based iterative methods to reduce PAPR through minimizing statistical parameters of the instantaneous power of GFDM signal including variance, power, and third moment, is suggested. Numerical results confirm when the step-size of the Gradient method is dynamically computed using the Wolf line search rule, the suggested algorithm circumvents drawbacks of existing studies and converges to a precoder providing advantages in design speed, obtained PAPR, symbol error rate, and out-of-band emission.<br>

Linear Precoder Design for PAPR Reduction of GFDM Signals Using Gradient Descent Methods

This paper addresses linear precoder design for Peak-to-Average Power Ratio (PARP) reduction of Generalized Frequency Division Multiplexing (GFDM). A general framework, which is composed of four different scenarios and utilizes Gradient-based iterative methods to reduce PAPR through minimizing statistical parameters of the instantaneous power of GFDM signal including variance, power, and third moment, is suggested. Numerical results confirm when the step-size of the Gradient method is dynamically computed using the Wolf line search rule, the suggested algorithm circumvents drawbacks of existing studies and converges to a precoder providing advantages in design speed, obtained PAPR, symbol error rate, and out-of-band emission.<br>

Flexible Spectral Precoding for OFDM Systems

Spectral precoding is a popular approach to reduce out-of-band radiation (OBR) in multicarrier systems in order to avoid adjacent channel interference. However, it introduces distortion in the data, appropriate decoding is required at the receiver side. Thus, trading off between implementation complexity, OBR reduction and error rate is important. We present a novel linear precoder design with flexibility to trade off OBR reduction, precoding/decoding complexity, and error rate at the receiver. Moreover, the constraint can be imposed on each subcarrier individually to provide more flexibility. The precoding matrices have low rank, which translates into significant computational savings. In this way, the requirements of different systems can be satisfied with varying complexity levels.