电子料做女学 University of Electroe Scioncad TechofChina /986 Chapter 10 Pipelined and Parallel Recursive and Adaptive Filters Xiang LING National key Lab of Science and Technology on Communications
Chapter 10 Pipelined and Parallel Recursive and Adaptive Filters Xiang LING National Key Lab of Science and Technology on Communications
S- 10.1 Introduction /96 IIR digital filters are often preferred since a specified spectrum can be implemented using a much lower order IIR filter than FIR. Recursive digital filters cannot be easily pipelined or processed in parallel due to the presence of feed back loops in this filter. ■ Look-ahead computation and incremental block processing techniques are used for pipelined and paralleled recursive digital filters. 2
2 10.1 Introduction IIR digital filters are often preferred since a specified spectrum can be implemented using a much lower order IIR filter than FIR. Recursive digital filters cannot be easily pipelined or processed in parallel due to the presence of feed back loops in this filter. Look-ahead computation and incremental block processing techniques are used for pipelined and paralleled recursive digital filters
10.2 Pipeline interleaving in digital filters 966 10.2.1 Inefficient single/multichannel interleaving y(n+1)=ay(n)+bu(n) u(n) a X X D y四 y(n+1) T=(Tm+T)/1 3
3 10.2 Pipeline interleaving in digital filters 10.2.1 Inefficient single/multichannel interleaving y(n 1) ay(n) bu(n) X + D X y(n) u(n) b a y(n+1) T (Tm Ta )/1
966 How to decrease 70？ An M-stage pipelined version by inserting (M-1) additional latches. a The clock period can be reduced by M times in principle. But the latency will increase to M clock periods. ■ For the case of a single time series,this array will be useful for only 20%of the time. u(n) 6 a 十 5D @ 4
4 How to decrease T∞ ? An M-stage pipelined version by inserting (M-1) additional latches. The clock period can be reduced by M times in principle. But the latency will increase to M clock periods. For the case of a single time series, this array will be useful for only 20% of the time. X + 5D X y(n) u(n) b a
/966 Pipeline interleaving approach is well suited for applications requiring nominal concurrency. u'( u2(n) 0 u(n)o uD)→o u(n)o a retime ①D-D-D-D-D Time 4 (n) 0 1 2 3 5 6 7 8 9 10 State Y1(0)Y2(0) Y3(0)Y40)Y5(0)Y1(1)Y2(1)Y31)Y41)Y5(1)Y1(2) 5
Pipeline interleaving approach is well suited for applications requiring nominal concurrency. 5 Time (n) State 0 1 2 3 4 5 6 7 8 9 10 Y1(0) Y2(0) Y3(0) Y4(0) Y5(0) Y1(1) Y2(1) Y3(1) Y4(1) Y5(1) Y1(2) retime