一种应用于多带正交频分复用超宽带的IFFT/FFT处理器

A FFT/IFFT Processor for MB-OFDM UWB Applications

针对多带正交频分复用超宽带(MB-OFDM UWB)系统,提出了一种高吞吐量、混合字长、混合基、4并行数据路径的128点IFFT/FFT处理器结构。该处理器采用具有误差补偿的改进Booth定长乘法器和CSD常量乘法器,有效地提高了精度和减少了硬件的复杂度。通过分析,本方案比混合基多路径延迟反馈(MRMDF)结构减少了49%的乘法器资源,在硬件开销相当的情况下,比双并行数据路径结构减少了30%的存储器资源和提高了33%的吞吐量,使该处理器在精度、硬件开销和速度上做了最好的折衷。在0.18 μm COMS工艺下,该处理器的最大工作频率达到300 MHz,吞吐量为1.2Gsamples/s,满足了吉比特无线个人域网络(WPAN)的要求。

This paper presents a high-throughput, hybrid word-length, mixed-radix, four-parallel data-path 128-point FFT/IFFT processor for MB-OFDM uhrawideband （UWB） systems. The proposed processor uses an error compensation method for modified booth fixed-width multipliers and canonic signed digit （CSD） multipliers, which leads to higher precision and lower hardware complexity. From analysis, it is shown that the proposed architecture can save 49% multipliers utilizations compared to MRMDF architecture, additional our proposed architecture can save 30% memory resource and be increased by 33% throughput rate compared to the two- parallel data-path architecture under the same hardware cost. So it makes the best balance of the precision, the hardware cost and the speed. Also, ours processor is designed using 0.18 um COMS process with a throughput rate of up to 1.2 Gsample/s at 300 MHz, which meets the requirements for gigabit WPAN.