Patent ID: 8437427
Filing Date: 2013-05-07
Classification: G06F

Abstract:
1. A frequency shifter for shifting an arbitrary frequency of an input signal in an arbitrary wireless communication system, comprising: a positive or negative frequency shift controller, used to provide a 1-bit controller PN which controls sign indicators S a counting up or down counter, receiving a phase increment per sampling instant and the sign indicator S a cosine function Look-Up-Table (LUT) T a phase shifter, receiving the sine and cosine values from the sine and cosine function LUTs and the sign indicators S wherein a mathematical relationship between the input and output of the phase shifter is described as follows: wherein a sampling rate of the frequency shifter is denoted as a positive number, f is a rational number defined in the following mathematical equation: wherein 0≦K<2M, M≠0, F, M, N and K are non-negative integers; and a notation, └x┘, is the largest integer which is equal to or smaller than a positive value x.