循環前綴錨點輔助時間序列多工

Abstract

透過在循環前綴正交分頻多工 (CP-OFDM) 調變前對多個數據區塊進行預編碼，矩形脈衝 CP-OFDM 幀調變架構可在線性時變多路徑 (LTV) 通道下實現較 CP-OFDM 更佳的錯誤效能。典型實例包括循環前綴正交時頻空間 (CP-OTFS)、循環前綴正交時序多工 (CP-OTSM)、循環前綴仿射分頻多工 (CP-AFDM)、循環前綴單載波 (CP-SC) 以及循環前綴錨點輔助單載波 (CP-ASC)。這些 CP-OFDM 幀調變各具理想但無法同時滿足的特性，包括對雙重通道色散的抵抗能力、低峰均功率比 (PAPR) 及高頻譜緊密度。 本文提出的循環前綴錨點輔助時序多工 (CP-ATSM) 在 CP-OFDM 幀調變架構中引入錨點符元插入、選擇性映射與均勻數據擴展技術。模擬結果顯示，CP-ATSM 在 LTV 通道下的未編碼錯誤效能與 CP-OTFS 及 CP-OTSM 相當，並優於 CP-AFDM、CP-SC 和 CP-ASC，同時相較於 CP-OTFS、CP-OTSM 及 CP-AFDM 具備更低的 PAPR。此外，CP-ATSM 在頻譜效率上與 CP-ASC 相當，並顯著優於 CP-OTFS、CP-OTSM、CP-AFDM 和 CP-SC。

By precoding multiple data bocks before cyclic-prefixed orthogonal frequency-division multiplexing (CP-OFDM) modulation, the rectangularly-pulsed CP-OFDM frame modulation structure has been adopted to achieve better error performance than CP-OFDM over linear time-varying multipath (LTV) channels. Typical embodiments include cyclic-prefixed orthogonal time frequency space (CP-OTFS), cyclic-prefixed orthogonal time sequency multiplexing (CP-OTSM), cyclic-prefixed affine frequency division multiplexing (CP-AFDM), cyclic-prefixed single carrier (CP-SC), and cyclic-prefixed anchor-aided single carrier (CP-ASC). These CP-OFDM frame modulations show various desirable but not simultaneously existing features, including resistance to double channel dispersion, low peak-to-average power ratio (PAPR), and high spectral compactness. By incorporating anchor-symbol insertion, selected mapping, and uniform data spreading into the CP-OFDM frame modulation structure, cyclic-prefixed anchor-aided time sequency multiplexing (CP-ATSM) is proposed in this paper. CP-ATSM performs comparably with CP-OTFS and CP-OTSM and outperforms CP-AFDM, CP-SC, and CP-ASC in uncoded error performance over LTV channels, while offering reduced PAPR compared to CP-OTFS, CP-OTSM, and CP-AFDM. Besides, CP-ATSM performs comparably with CP-ASC and outperforms CP-OTFS, CP-OTSM, CP-AFDM, and CP-SC significantly in spectral efficiency.