Method and apparatus for generating signal having converted sampling rate in communication system

Patent metadata

Field	Value
Publication number	US-9240771-B2
Application number	US-201213368656-A
Country	US
Kind code	B2
Filing date	Feb 8, 2012
Priority date	Feb 8, 2011
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

A method of generating a signal having a converted sampling rate in a communication system is provided. The method includes selecting effective input samples among S number of input samples included in an input stream corresponding to an input sampling rate, generating a filter coefficient set including filter coefficients having a length of a second tap, the filter coefficients having the length of the second tap being generated by dividing a filter coefficient having a length of a first tap configuring a low-pass filter into the filter coefficients having the length of the second tap corresponding to a number of selected effective input samples, selecting filter coefficients corresponding to each of the effective input samples among the filter coefficients included in the filter coefficient set, and outputting output samples having an output sampling rate which is converted from the input sampling rate.

First claim

What is claimed is:

1. A method of a communication device configured to generate a signal corresponding to a converted sampling rate in a communication system, the method comprising:
receiving, by a sampling rate converting device, a stream of input samples having an input sampling rate corresponding to a first baseband sampling rate of a first communication system;
generating a filter coefficient set comprising a number of filter coefficient vectors, the filter coefficients being generated by dividing a filter coefficient set having a length of a first tap configuring a low-pass filter into the filter coefficient vectors, a length of each filter coefficient vector corresponding to a length of a second tap;
comparing the input sampling rate and an output sampling rate;
based on the comparison, performing a first adaptive filtering process when the input sampling rate is larger than the output sampling rate, and performing a second adaptive filtering process when the input sampling rate is smaller than the output sampling rate; and
generating, by the sampling rate converting device, an output signal with the converted sampling rate corresponding to the output sampling rate, wherein the converted sampling rate corresponds to a second baseband sampling rate of a second communication system;
wherein performing the first adaptive filtering process includes:
selecting at least one non-zero input sample corresponding to the input sampling rate for input samples corresponding to the output sampling rate among input samples included in the stream corresponding to the input sampling rate, wherein the number of selected input samples corresponds to the length of the second tap;

selecting at least one filter coefficient corresponding to each of the at least one non-zero input sample in the filter coefficient set, comprising adding a difference number of filter coefficient vectors to filter coefficient vectors corresponding to the input sampling rate, wherein the difference number is a value obtained by subtracting a number corresponding to the input sampling rate from a number corresponding to the output sampling rate,
outputting output samples corresponding to the output sampling rate which is converted by the sampling rate converting device from the input sampling rate so as to correspond to the converted rate by multiplying each of the at least one non-zero input sample and the selected at least one filter coefficient based on the comparison result.

2. The method as claimed in claim 1 , wherein if the input sampling rate is smaller than the output sampling rate, doubly selecting some input samples from input samples corresponding to the output sampling rate among the input samples and selecting the at least one non-zero input sample corresponding to the input sampling rate.

3. The method as claimed in claim 2 , wherein the selecting of the at least one filter coefficient comprises selecting at least one filter coefficient vector corresponding to the output sampling rate in the filter coefficient set.

4. A communication device configured to generate a signal corresponding to a converted sampling rate in a communication system, the device comprising:
an input buffer configured to store a stream of input samples corresponding to an input sampling rate received in a first communication system using a first baseband sampling rate; and
a baseband sampling rate converting device comprising a controller configured to:
generate a filter coefficient set comprising a number of filter coefficient vectors, the filter coefficients being generated by dividing a filter coefficient set having a length of a first tap configuring a low-pass filter into the filter coefficient vectors, a length of each filter coefficient vector corresponding to a length of a second tap,
compare the input sampling rate and an output sampling rate, and based on the comparison, control the performance of a first adaptive filtering process when the input sampling rate is larger than the output sampling rate, and
control the performance of a second adaptive filtering process when the input sampling rate is smaller than the output sampling rate, and
control an output buffer such that the output buffer outputs output samples corresponding to the output sampling rate which is converted from the input sampling rate so as to correspond to a conversion rate among output samples output from a low-pass filter based on the comparison result,

wherein performing the first adaptive filtering process includes:
selecting at least one non-zero input sample corresponding to the input sampling rate for input samples corresponding to the output sampling rate among input samples included in the stream corresponding to the input sampling rate, wherein the number of selected input samples corresponds to the length of the second tap,
selecting at least one filter coefficient corresponding to the at least one non-zero input sample in the filter coefficient set, comprising adding a difference number of filter coefficient vectors to filter coefficient vectors corresponding to the input sampling rate, wherein the difference number is a value obtained by subtracting a number corresponding to the input sampling rate from a number corresponding to the output sampling rate, and
controlling the low-pass filter such that the at least one non-zero input sample is multiplied with the selected at least one filter coefficient.

5. The device of claim 4 , wherein if the input sampling rate is smaller than the output sampling rate, the controller is configured to doubly select some input samples from input samples corresponding to the output sampling rate among the input samples and to select the at least one non-zero input sample corresponding to input sampling rate.

6. The device of claim 5 , wherein the controller selects at least one filter coefficient vector corresponding to the output sampling rate in the filter coefficient set.

Assignees

• Lee Joo-Hyun
• Jo Sung-Kwon
• Yang Ha-Young
• Samsung Electronics Co Ltd

Inventors

• Lee Joo-Hyun
• Jo Sung-Kwon
• Yang Ha-Young

Classifications

• H04B1/0017

  Digital filtering (H04B1/001 takes precedence; digital filters per se H03H17/00) · CPC title

• H03H17/0685 Primary

  the ratio being rational · CPC title

• H04B1/0021

  Decimation, i.e. data rate reduction techniques (H04B1/0025 takes precedence) · CPC title

• H03H17/0628

  the input and output signals being derived from two separate clocks, i.e. asynchronous sample rate conversion · CPC title