考虑HPA非线性的NC-OFDM系统最优参数设计

Optimal Parameters Design of NC-OFDM Systems with the Consideration of HPA Nonlinearity

给出了计算非连续OFDM(NC-OFDM)系统带外功率泄漏和主用户(PU)频带干扰功率的数学模型,在此基础上,把NC-OFDM系统参数设计问题转化为次用户(SU)频谱开销和主用户(PU)干扰温度限制下的非线性规划问题的优化求解.给出了NC-OFDM系统最优参数与高功率放大器(HPA)的输入回退(IBO)参数、PU频带占用率和PU干扰温度容限之间的关系.仿真结果表明,当PU频带占用率和干扰容限给定的条件下,求解所建立的优化问题可以为SU设计最佳的系统参数:最少的保护载波数及系统对功率放大器IBO参数的要求.

A mathematical model for computing the out-of band （OOB） leakage radiation in NC- OFDM systems and the interference to the adjacent primary users （PUs） is presented in this paper. Based on this mathematical model, the optimal parameters could be obtained by solving the nonlinear programming （NLP） problem subject to secondary users（SUs）＇ spectrum overhead and PUs＇ occupancy rate r. The results showed the close relationship between the number of guard subcarriers and the parameters of input back off （IBO） as well as PU occupancy r and interference temperature tolerance. The simulation results have shown that, under the conditions of given PU occupancy r and PU interference temperature limit, the solution of proposed programming problem can be used to design the optimal system parameters for secondary users with the smallest number of guard subcarriers and the demand of system to the parameters of IBO.