# US 5,703,913 A · Timing signal generator

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- Number: US 5,703,913 A
- Document ID: US5703913A
- Status: Granted
- Kind: A
- Application number: 08/684,442
- Filed: 1996-07-19
- Granted: 1997-12-30
- Earliest claimed: 1992-06-19
- Assignees: Matsushita Electric Industrial Co., Ltd.
- Inventors: Yuuri Yamamoto; Kenichi Takahashi; Hiroshi Ohnishi; Yoshinori Kunieda; Naoki Matsubara
- Web page: https://patentgrep.com/patent/US5703913A

## CPC

- H04L 7/0334: {Processing of samples having at least three levels, e.g. soft decisions}
- H04L 27/2332: {using a non-coherent carrier}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A timing signal generator includes a demodulator for an input modulated signal to provide first and second baseband signals having a quadrature relation relative to each other. A converter is used to convert the first and second baseband signals into angle data representing a phase, and a calculator is used to calculate a difference between the phase represented by current angle data and the phase represented by previous angle data, preceding the current angle data by a 1-symbol interval. The calculator outputs data representative of the calculated phase difference. A further converter converts the calculator output data into a binary reference signal responsive to which of predetermined divided regions contains a point corresponding to the calculated difference data. Also included is a generator for generating a symbol timing signal in synchronism with the binary reference signal.

## Claims

### Claim 1

A timing signal generator comprising:
means for demodulating an input modulated signal into first and second baseband signals having a quadrature relation with each other;
means for converting the first and second baseband signals into angle data representing a phase;
means for calculating a difference between the phase represented by the current angle data and the phase represented by the previous angle data which precedes the current angle data by a 1-symbol interval, and outputting data representative of the calculated phase difference;
means for determining which of predetermined divided regions contains a point corresponding to the calculated difference data;
means for converting the output data of the calculating means into a binary reference signal in response to which of the predetermined divided regions contains the point corresponding to the calculated difference data; and
means for generating a symbol timing signal in synchronism with the binary reference signal.

### Claim 2 (depends on 1)

The timing signal generator of claim 1, wherein said means for determining determines a surface in accordance with the calculated phase difference, said predetermined divided regions being regions of said surface.

### Claim 3 (depends on 2)

The timing signal generator of claim 2 wherein said surface comprises a two dimensional plane determined by quadrature phase difference and in-phase phase difference.

### Claim 4 (depends on 3)

The timing signal generator of claim 3 wherein said divided regions comprise four regions corresponding to predetermined phase differences.

### Claim 5 (depends on 1)

The timing signal generator of claim 1, further comprising means for detecting a predetermined pattern of the binary reference signal, and means for controlling the symbol timing signal generating means in response to the detected predetermined pattern.

### Claim 6 (depends on 5)

The timing signal generator of claim 5, wherein said means for determining determines a surface in accordance with the calculated phase difference, said predetermined divided regions being regions of said surface.

### Claim 7 (depends on 6)

The timing signal generator of claim 6 wherein said surface comprises a two dimensional plane determined by quadrature phase difference and in-phase phase difference.

### Claim 8 (depends on 7)

The timing signal generator of claim 7 wherein said divided regions comprise four regions corresponding to predetermined phase differences.