改进的OFDM系统自适应资源分配算法

在自适应正交频分复用(OFDM： Orthogonal Frequency Division Multiplexing)系统中, 传统迭代注水功率分配（IWFP： Iterative Water Filling Power）算法对星座规模量化程度要求过高, 实际应用性不强。为此, 在发射总功率和系统误码率上限恒定的条件下, 提出了一种基于IWFP算法的改进算法。该算法在IWFP算法基础上进行了比特和功率分配的二次调整, 算法更加符合系统调制的星座规模和实际发射需求。仿真结果表明, 在误比特率（BER： Bit Error Rate）为10^-4时, 改进算法对信噪比的要求比IWFP算法高约3 dB, 比未经自适应调制的OFDM系统功率比特分配算法即等功率分配算法（EPA： Equalization Power Algorithm）低8 dB, 接近于系统的最优性能, 且运算复杂度不高。

Improved Adaptive Resource Allocation Algorithm for OFDM Systems

An efficient power and bit allocation algorithm based on IWFP （Iterative Water-Filling Power） algorithm is proposed for the adaptive OFDM （Orthogonal Frequency Division Multiplexing） systems.The traditional iterative water-filling power allocation algorithm needs high scale of constellation quantitative and does not fit for the practical applications.The proposed algorithm has a bit and power allocation of secondary adjustment,which conforms to the size of modulation constellation and the actual emission requirements.The simulation results show that with the same BER（Bit Error Rate）of 10-4 the required SNR （Signal-to-Noise Ratio） in proposed algorithm is higher than IWFP algorithm nearly 3 dB.The proposed algorithm is lower than that in the traditional distribution algorithm by nearly 8 dB.The proposed algorithm is close to the optimal performance of the system with the low complexity of computing.