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A high speed N × N bit multiplier architecture that supports signed and unsigned multiplication operations is proposed in this paper. This architecture incorporates the modified two's complement circuits and also N × N bit unsigned multiplier circuit. This unsigned multiplier circuit is based on decomposing the multiplier circuit into smaller-precision independent multipliers using Vedic Mathematics. These individual multipliers generate the partial products in parallel for high speed operation, which are combined by using high speed adders and parallel adder to generate the product output. The proposed architecture has regular-shape for the partial product tree that makes easy to implement. Finally, this multiplier architecture is implemented in UMC 65 nm technology for N = 8, 16 and 32 bits. The synthesis results shows that the proposed multiplier architecture improves in terms of speed and also reduces power-delay product (PDP), compared to the architectures in the literature.

The authors present a novel 16/32/64/128-point single-path delay feedback pipeline fast Fourier transform (FFT) architecture targeting the multi-rate and multi-regional orthogonal frequency division multiplexing (MR-OFDM) physical layer of IEEE 802.15.4-g. The proposed FFT architecture employs a mixed-radix algorithm to significantly reduce the number of complex multipliers. It utilises a configurable complex constant multiplier structure instead of a fixed constant multiplier to efficiently conduct W 32 , W 64 , and W 128 twiddle factor multiplication. A hardware-sharing mechanism has also been formulated to reduce the memory space requirements of the proposed 16/32/64/128-point FFT computation scheme. The proposed design is implemented in Xilinx Virtex-5 and Altera's field-programmable gate array devices. For the computation of 128-point FFT, the proposed mixed-radix FFT architecture significantly reduces the hardware cost in comparison with existing FFT architecture. The proposed FFT architecture is also implemented by adopting the 90 nm complementary metal-oxide-semiconductor technology with a supply voltage of 1 V. Post-synthesis results reveal that the design is efficient in terms of gate count and power consumption, compared to earlier reported designs. The proposed variable-length FFT architecture gate count is 22.3K and consumes 3.832 mW, while the word-length is 12-bits and can be efficiently useful for the IEEE 802.15.4-g standard.

A fixed-width multiplier receives two n-bit operands and generates an approximate n-bit product as the output. It truncates part of the partial products and employs an appropriate error compensation circuit in order to reduce the approximation error. In this study, a new error compensation circuit for the fixed-width multiplier has been proposed which utilises the correction vector (CV) and modified minor CV. The proposed error compensation circuit is capable of minimising both the mean error and the mean-square error. Post-synthesis results for 16-bit of fixed-width multiplier demonstrate that the proposed circuit has 3.50, 39.24, 42.91 and 44.91% reduced delay, area, power consumption and power-delay product when compared with the existing design reported in the literature.

Present it is most needful task to get various applications with parallel computations by using a Fast Fourier Transform (FFT) and the derived outputs should be in regular format. This can be achieved by using an advanced technique called Multipath delay commutator (MDC) Pipelining FFT processor and this processor will be capable to perform the computation of a different data streams at a time. In this paper the design and implementation of AGU based Pipelined FFT architecture is done Caluclation of a butterfly is done within 2 cycles by the instructions proposed. A Data Processing Unit (DPU) is employed in this pipeline architecture and supports the instructions & an FFT Adress Generation Unit (FAGU) caluclates butterfly input & output data adresses automatically. The DPU proposed sysyem requires less area compared to commericial DSP chips. Futhermore, the proposed FAGU reduces the number of FFT computation cycles. The FFT design architecture will have real data paths. With various FFT sizes, different radix & various parallesim levels, the FFT can be mapped to the pipeline architecture. The most attractive feature of the pipelined FFT architecture is it consists of bit reversal operation so it requires little number of registers and better throughput.