公开(公告)号：RU2189109C2

公开(公告)日：2002-09-10

申请号：RU99101863

申请日：1997-06-23

Applicant: QUALCOMM INC

Inventor： ISTON KENNET D ,  BLEHK PITER DZH

IPC: H03H17/06

Abstract: telephone communications. SUBSTANCE: filter 20 is implemented as table 104 using read-only memory (ROM). Finite impulse response (FIR) table is designed to store pre-calculated output values of filter for each output-values permissible combination 102 subject to filtration. Input value streams are sequentially shifted to table with aid of shift register 106 and respective output values are sequentially passed to output. Telephone set uses data burst randomization unit 18 to produce data signal incorporating zero value sequences and opposing-value sequences (+1 and 1). Therefore permissible input combinations for FIR filter include only combinations incorporating either all signals with opposing values, all zero signals, initial opposing-value signals followed by zero signals, or initial zero signals followed by opposingvalue signals. Conversion table of FIR filter is configured with due account of these restrictions for input streams which enables producing conversion table having relatively low number of records. EFFECT: enhanced filter efficiency. 24 cl, 9 dwg