A novel OFDM-based waveform with low peak-to-average power ratio (PAPR) and high robustness against phase noise (PN) is presented. It follows the discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM) signal model. 3MSK, is inspired by continuous-phase frequency shift keying (FSK), but it uses three frequencies in the baseband model -- specifically, 0 and $\pm f_{symbol}/4$, where $f_{symbol}$ is the symbol rate -- which effectively constrains the phase transitions between consecutive symbols to 0 and $\pm \pi/2$ rad. Motivated by the phase controlled model of modulation, different degrees of phase continuity can be achieved, while supporting receiver processing with low complexity. The signal characteristics are improved by generating an initial time-domain nearly constant envelope signal at higher than the symbol rate. This helps to reach smooth phase transitions between 3MSK symbols. Also the possibility of using excess bandwidth is investigated by transmitting additional non-zero subcarriers outside active subcarriers of the basic DFT-s-OFDM model, which provides the capability to greatly reduce the PAPR. Due to the fact that the information is encoded in the phase transitions, a receiver model that tracks the phase variations without needing reference signals is developed. To this end, it is shown that this new modulation is well-suited for non-coherent receivers, even under strong phase noise (PN) conditions, thus allowing to reduce the overhead of reference signals. Evaluations of this physical-layer modulation and waveform scheme are performed in terms of transmitter metrics such as PAPR, OOB emissions and achievable output power after the power amplifier (PA). Finally, coded radio link evaluations are also shown and provided, demonstrating that 3MSK has a similar BER performance as that of traditional QPSK.
翻译:提供了一种新型的基于调频器的波形, 以低峰至平均电率( PARP) 和高强度抗阶段噪音( PN) 。 它沿离异的 Fleier 变异 垂直频率分流多氧化( DFT- s- OFDM) 信号模型( DFT- S- OFDM) 。 3MSK 受到连续阶段频率转换键( FSK ) 的启发, 但是它使用基带模型的三个频率, 具体来说, 0 美元 和 $\ pm fsymbol} /4 。 美元 代表率是 美元 的 传统调频率 -- -- 有效地制约了连续符号到 0 和 $\ pm 接收器信号( PNPN) 之间的阶段转换 。 使用超频频带( QRM ) 将额外的非零级次级参考值转换到 QQRM 。 因此, 阶段可以支持接收 IMFD 阶段,, 新的 将 IMFD 显示 3 变 。