OFDM中基于预加载的比特和功率分配算法

Bit and power allocation algorithm based on preload in OFDM system

在总功率和比特数不变的情况下,针对误码率最小化BM(Ber Minimum)的比特和功率联合分配算法计算量大的缺点,提出一种以最小总名义功率为目标、基于预加载的自适应比特和功率分配算法.论述了最小总名义功率的比特加载同误码率最小化的比特加载是同解的,并在最优比特加载结果的基础上求解了最优功率分配方案和次优分配方案.然后以最小总名义功率为目标,提出基于误码率门限比特预加载的比特和功率分配快速算法,减少了搜索最优解的迭代次数,从而提高算法的效率.仿真结果表明,所提出的方法在保证误码率性能前提下,提高了计算速度.

In OFDM system, a bit and power allocation method based on bit -preloading is proposed in order to achieve a result with minimum Bit Rate Error （BER） under the constraint of total transmission power and data rate within a shorter calculation time. It is proved that the bit-loading result of Minimum Total Virtual Power （MTVP） is the same as that of minimizing BER. Then an iteration method aiming at the MTVP is proposed, in which the preload of bit according to BER threshold is used to decrease the iteration times. The simulation shows that the proposed bit and power allocation method based on preload approaches the optimal solution as well as computes efficiently.