Voice-channel frequency synchronization

• US 6,118,770 A
• Filed: 05/21/1998
• Issued: 09/12/2000
• Est. Priority Date: 06/04/1997
• Status: Expired due to Term

• Current Assignee: ST-Ericcson SA (Telefonaktiebolaget LM Ericsson)
• Original Assignee: DSPC Technologies Limited
• Inventors: Shatit, Biniamin, Pianka, Boaz
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US09/083,865
• Time in Patent Office: 845 Days
• Field of Search: 370/503, 370/350, 370/324, 370/516, 370/518, 375/294, 375/327, 375/356, 375/376, 375/362, 375/371, 375/354, 375/355, 375/344, 455/502
• US Class Current: 370/324
• CPC Class Codes: H03L 7/22 using more than one loop
• CPC Class Codes: H04J 3/0685 Clock or time synchronisation in a node; Intranode synchronisation
• CPC Class Codes: H04L 7/0331 with a digital phase-locked loop [PLL] processing binary samples, e.g. add/subtract logic for correction of receiver clock H04L7/0337 takes precedence

Abstract

A synchronized frequency generating system is provided which includes a main crystal clock, for producing a basic frequency F_B, a channel sampling phase locked loop (PLL) unit, connected to the main crystal clock, for converting the basic frequency F_B into a channel sampling frequency F_CS, a voice sampling PLL unit, connected to the main crystal clock, for converting the basic frequency F_B into a voice sampling frequency F_VS, a time tracking unit, connected to the channel sampling PLL unit, for detecting signal characteristics so as to determine a channel sampling frequency phase change value Δφ_CS and a frame timing phase change value Δφ_FRAME, and a frequency controller, connected to the voice sampling PLL. The frequency controller receives channel sampling frequency phase adjustment data and determines a voice sampling frequency phase change value Δφ_VS. The frequency controller provides the voice sampling frequency phase change value Δφ_VS to the voice sampling PLL.

Claims

1. A synchronized frequency generating system comprising:

a. a main crystal clock, for producing a basic frequency F_B ;

b. a channel sampling phase locked loop (PLL) unit, connected to said main crystal clock, for converting said basic frequency F_B into a channel sampling frequency F_CS ;

c. a voice sampling PLL unit, connected to said main crystal clock, for converting said basic frequency F_B into a voice sampling frequency F_VS ;

d. a time tracking unit, connected to said channel sampling PLL unit, for detecting signal characteristics so as to determine a channel sampling frequency phase change value Δ

φ

_CS and a frame timing frequency change value Δ

φ

_FRAME ; and

e. a frequency controller, connected to said voice sampling PLL,

wherein said frequency controller receives channel sampling frequency phase adjustment data, thereby determining a voice sampling frequency frequency change value Δ

φ

_VS, and

wherein said frequency controller provides said voice sampling frequency phase change value Δ

φ

_VS to said voice sampling PLL.

2. The system according to claim 1 wherein said frequency controller receives channel sampling frequency phase adjustment data from said time tracking unit.

3. The system according to claim 1 wherein said frequency controller receives channel sampling frequency phase adjustment data from said channel sampling PLL.

4. The system according to claim 1 further comprising a primary voice sampling PLL connected between said voice sampling PLL and said main crystal clock,

wherein said primary voice sampling PLL converts said basic frequency F_B into primary channel sampling frequency F_CS1 and said voice sampling PLL converts said primary channel sampling frequency F_CS1 into a channel sampling frequency F_CS.

5. The system according to claim 4 wherein said primary voice sampling PLL converts said basic frequency F_B into primary channel sampling frequency F_CS1, by changing the voice sampling phase.

6. The system according to claim 4 wherein said voice sampling PLL converts said primary channel sampling frequency F_CS1 into a channel sampling frequency F_CS, by changing the voice sampling phase.