Abstract:

The problem of high Peak to Average Power Ratio(PAPR) is an obstruction to the hardware implementation which restricts the practicability of Non-contiguous Orthogonal Frequency Division Multiplexing (NC-OFDM) seriously.To solve this problem,an improved PAPR reduction algorithm based on the Tone Reservation(TR) technique is proposed.According to the results of spectrum sensing,the bands ware divides into two categories according to whether or not there are primary users.Secondary users choose different numbers and amplitudes of the reversed subcarriers in those bands separately.In this way,secondary users get a substantial PAPR reduction while avoiding the interference to the primary users and increasing the utilization efficiency of spectrum.Theory analysis and simulation results show that the proposed algorithm gives a good PAPR reduction performance and supports efficient use of spectrum as well.

Key words: cognitive radio, Non-contiguous Orthogonal Frequency Division Multiplexing(NC-OFDM), Tone Reservation(TR), Peak to Average Power Ratio(PAPR)

摘要：

在非连续正交频分复用系统中,由于峰值功率平均比(PAPR)较高,导致发射端硬件设备难以实现,严重制约其实用性。为此,提出一种改进型子载波预留PAPR抑制算法。根据频谱感知结果,分别在主用户使用频段和未使用频段内合理选取预留子载波,并通过自适应调整频段内预留子载波的数目和幅值,在满足对主用户不造成干扰或次用户频谱利用率提高的条件下,使整个非连续正交频分复用系统的PAPR得到有效抑制。理论分析和仿真结果表明,与传统算法相比,改进的子载波预留PAPR抑制算法在提高认知用户频谱利用率的同时,具有较好的峰均比抑制性能。

关键词: 认知无线电, 非连续正交频分复用, 子载波预留, 峰值功率平均比

CLC Number: 

• TP391