Hardware Efficient Implementation of Finite Impulse Response Filters With Limited Range Input Signals
4 Assignments
0 Petitions
Accused Products
Abstract
Disclosed herein is a method and system to reduce the area and power dissipation in digital filters or multipliers Compared to radix-4 Booth coding the proposed method reduces the number of partial products by one, if the input signal has certain limits on its range. One exemplary application is echo cancellation in a full duplex pulse amplitude modulation system with 10 levels (PAM-10). Echo cancellation may be achieved by calculating a digital replica of the echo from the transmission channel. The replica signal may be calculated in a finite impulse response (FIR) filter, which multiplies the transmitted signal with estimates of the echo coefficients of the transmission channel The replica signal may be subtracted from the received signal to create an echo-free receive signal. The disclosed method may reduce the number of partial products between the PAM-10 transmit signal and each echo coefficient from three, when radix-4 Booth coding is used, to two. This in turn may reduce the number of adders in each tap multiplier of the FIR filter from two to one, resulting in lower area, lower power dissipation, and potentially higher switching speeds.
17 Citations
57 Claims
-
1-23. -23. (canceled)
-
24. A system for processing a signal, the system comprising:
one or more circuits operable to, at least;
encode the signal employing a coding process, the coding process producing symbolic values; and
modify the symbolic values by reducing a number of digits employed to express the symbolic values. - View Dependent Claims (25, 26, 27, 28, 29, 30)
-
31. One or more circuits for increasing a bit rate of transmission of a signal, the one or more circuits comprising:
at least one processor operable to, at least;
encode the signal to produce symbolic values having a particular number of digits; and
modify the symbolic values by reducing the number of digits used to express the symbolic values. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38)
-
39. A digital filter comprising:
one or more circuits operable to, at least;
receive symbolic values representing a signal, the symbolic values produced by encoding the signal to a particular number of digits;
modify the symbolic values to reduce the number of digits used to express the symbolic values;
multiply the symbolic values by coefficients to form a plurality of products;
sum the plurality of products; and
output the sum. - View Dependent Claims (41, 40, 42, 43)
-
44. One or more circuits for increasing a bit rate of transmission of a signal, the one or more circuits comprising:
at least one processor operable to, at least;
encode the signal employing a coding process, the coding process producing symbolic values; and
modify the symbolic values by reducing a number of digits employed to express the symbolic values. - View Dependent Claims (45, 46, 47, 48, 49, 50)
-
51. A system for processing a signal, the system comprising:
one or more circuits operable to, at least;
encode the signal to produce symbolic values having a particular number of digits; and
modify the symbolic values by reducing the number of digits used to express the symbolic values. - View Dependent Claims (52, 53, 54, 55, 56, 57)
Specification