On-Chip Implementation of High Resolution High Speed Floating Point Adder/Subtractor with Reducing Mean Latency for OFDM

Problem statement: Fast Fourier Transform (FFT) is widely applied in OFDM trance-receiver communications system. Hence efficient FFT algorithm is always considered. Approach: This study proposed FPGA realization of high resolution high speed low latency floating point adder/subtractor for FFT in OFDM trance-receiver. The design was implemented for 32 bit pipelined adder/subtractor which satisfied IEEE-754 standard for floating-point arithmetic. The design was focused on the trade-off between the latency and speed improvement as well as resolution and silicon area for the chip implementation. In order to reduce the critical path and decrease the latency, the novel structure was designed and investigated. Results: Consequently, synthesis report indicated the latency of 4 clock cycles due to each stage operated within just one clock cycle. The unique structure of designed adder well thought out resulted 6691 equivalent gate count and lead us to obtain low area on chip. Conclusion: The synthesis Xilinx ISE software provided results representing the estimated area and delay for design when it is pipelined to various depths. The report showed the minimum delay of 3.592 ns or maximum frequency of 278.42 MHz.