Timing regenerating device

• US 8,462,875 B2
• Filed: 07/20/2009
• Issued: 06/11/2013
• Est. Priority Date: 07/20/2009
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Fujimura, Akinori, Takeda, Keishi
• Primary Examiner(s): Nguyen, Leon-Viet
• Assistant Examiner(s): Hassan, Sarah
• Application Number:
  US12/505,687
• Publication Number:
  US 20110013674A1
• Time in Patent Office: 1,422 Days
• Field of Search: 375/295, 370/350
• US Class Current: 375/295
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/7085 using a code tracking loop, e.g. a delay-locked loop

Abstract

A timing regenerating device regenerates a process timing for demodulating a reception signal in a spread spectrum communication system. The timing regenerating device includes a signal extracting unit that extracts a baseband signal from the reception signal on which an inverse spread processing is performed and a reference clock generating unit that converts the baseband signal into an electric power and generates a reference clock for a latch timing of the baseband signal output from the signal extracting unit based on the electric power.

Claims

1. A timing regenerating device that regenerates a process timing for demodulating a reception signal in a spread spectrum communication system, the timing regenerating device comprising:

a signal extracting unit that extracts a baseband signal from the reception signal on which an inverse spread processing is performed; and

a reference clock generating unit that converts the baseband signal into an electric power and generates a reference clock for a latch timing of the baseband signal output from the signal extracting unit based on the electric power, wherein

the reference clock generating unit includes

an electric power converting unit that converts the baseband signal into the electric power,

a cyclic adding unit that includes a plurality of information holding units, adds a value obtained by multiplying an oldest piece of information out of pieces of information held by the information holding units by an oblivion coefficient to the electric power, and replaces the oldest piece of information with a result of addition,

an information detecting unit that, for every predetermined period, detects a maximum value from among the pieces of information held in the information holding units and rank order information indicating a rank order at which the maximum value is obtained as the result of addition, and

a clock generating unit that generates the reference clock based on the rank order information.

2. The timing regenerating device according to claim 1, wherein the signal extracting unit includes

an integrating unit that integrates the reception signal over M sampling intervals and divides a result of integration by M for every period M, where M is a positive integer, and

a moving average processing unit that performs an averaging operation on latest N signals output from the integrating unit, where N is a positive integer.

3. The timing regenerating device according to claim 2, wherein M and N are determined based on a circuit size and a number of samplings per bit period of transmission data.

4. The timing regenerating device according to claim 1, wherein the predetermined period is a bit period of transmission data.