# US 2017/0288924 A1 · Receiving device and receiving method, and transmitting/receiving system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2017/0288924 A1
- Document ID: US20170288924A1
- Status: Published application
- Kind: A1
- Application number: 15/513,889
- Filed: 2015-07-31
- Published: 2017-10-05
- Earliest claimed: 2014-11-13
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Aki KAIZU; Masataka IMAO; Eiji MATSUO
- Web page: https://patentgrep.com/patent/US20170288924A1

## CPC

- H04L 27/22: Demodulator circuits; Receiver circuits
- H03L 7/08: Details of the phase-locked loop
- H04B 1/0007: {wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage}
- H04L 7/0066: {detection of error based on transmission code rule}
- H04L 7/04: Speed or phase control by synchronisation signals {(H04L7/0075 takes precedence)}
- H04L 25/49: using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels {; Baseband coding techniques specific to data transmission systems (spectral shaping H04L25/03828)}
- H04L 25/4902: {Pulse width modulation; Pulse position modulation}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B)
- H04B: TRANSMISSION

## Abstract

A receiving device includes: a receiver that receives a signal including PPM symbols; a clock generator that generates a clock for sampling; an A/D converter that digital-converts the received signal; a reference position detector that detects a leading position of the PPM symbols based on data from the A/D converter; and a clock error detector that detects a clock error. The clock error detector includes: a pulse position detector that detects a pulse position in the PPM symbols based on data from the reference position detector and A/D converter; a position error calculator that calculates a deviation of the pulse position based on data from the reference position detector, A/D converter, and pulse position detector; and a clock error calculator that calculates the clock error based on data from the position error calculator. The receiving device varies a frequency of the clock based on data from the clock error calculator.

## Claims

### Claim 1

A receiving device comprising:
a receiver that receives a signal including a plurality of PPM symbols;
a clock generator that generates a clock for sampling with respect to the signal received by the receiver;
an A/D converter that digital-converts the received signal on a basis of the sampling;
a reference position detector that detects a leading position of the PPM symbols on a basis of data from the A/D converter; and
a clock error detector that detects a clock error,
wherein the clock error detector includes:
a pulse position detector that detects a pulse position in the PPM symbols on a basis of data from the reference position detector and the A/D converter;
a pulse position error calculator that calculates a deviation of the pulse position on a basis of data from the reference position detector, the A/D converter, and the pulse position detector; and
a clock error calculator that calculates the clock error on a basis of data from the pulse position error calculator, and
wherein the receiving device varies a frequency of the clock generated by the clock generator, on a basis of data from the clock error calculator.

### Claim 2 (depends on 1)

The receiving device of claim 1, wherein the clock error detector further includes a pattern determiner that detects a region in which there is no pulse, on a basis of data from the pulse position detector, and
wherein the pulse position detector performs no pulse search in a predetermined region related to the region in which there is no pulse, on a basis of data from the pattern determiner.

### Claim 3

(canceled)

### Claim 4

A receiving method comprising:
a reception step of receiving a signal including a plurality of PPM symbols;
a clock generation step of generating a clock for sampling with respect to the signal received in the reception step;
an A/D conversion step of digital-converting the received signal on a basis of the sampling;
a reference position detection step of detecting a leading position of the PPM symbols on a basis of data obtained in the A/D conversion step; and
a clock error detection step of detecting a clock error,
wherein the clock error detection step includes:
a pulse position detection step of detecting a pulse position in the PPM symbols on a basis of data obtained in the reference position detection step and the A/D conversion step;
a pulse position error calculation step of calculating a deviation of the pulse position on a basis of data obtained in the reference position detection step, the A/D conversion step, and the pulse position detection step; and
a clock error calculation step of calculating the clock error on a basis of data obtained in the pulse position error calculation step, and
wherein the receiving method varies a frequency of the clock generated in the clock generation step, on a basis of data obtained in the clock error calculation step.

### Claim 5

A transmitting/receiving system comprising:
a transmitter that transmits a signal including a plurality of PPM symbols;
a receiver that receives the signal transmitted from the transmitter;
a clock generator that generates a clock for sampling with respect to the signal received by the receiver;
an A/D converter that digital-converts the received signal on a basis of the sampling;
a reference position detector that detects a leading position of the PPM symbols on a basis of data from the A/D converter;
a clock error detector that detects a clock error;
a demodulator that, after the detection of the leading position of the PPM symbols, demodulates the PPM symbols on a basis of data from the reference position detector;
an image display controller that controls a display image on a basis of data from the demodulator; and
a display that displays the display image,
wherein the clock error detector includes:
a pulse position detector that detects a pulse position in the PPM symbols on a basis of data from the reference position detector and the A/D converter;
a pulse position error calculator that calculates a deviation of the pulse position on a basis of data from the reference position detector, the A/D converter, and the pulse position detector; and
a clock error calculator that calculates the clock error on a basis of data from the pulse position error calculator, and
wherein the transmitting/receiving system varies a frequency of the clock generated by the clock generator, on a basis of data from the clock error calculator.

### Claim 6 (depends on 1)

The receiving device of claim 1, further comprising a demodulator that, after the detection of the leading position of the PPM symbols, demodulates the PPM symbols on a basis of data from the reference position detector.

### Claim 7 (depends on 6)

The receiving device of claim 6, further comprising:
a clock error accumulator that obtains an accumulated value of the clock error on a basis of data from the clock error detector; and
a clock error corrector that performs sample insertion or deletion on an output of the A/D converter, on a basis of data from the clock error accumulator,
wherein the clock generator does not vary the frequency of the clock for sampling, and
wherein the reference position detector, the clock error detector, and the demodulator perform processing on a basis of data from the clock error corrector without using data from the A/D converter.

### Claim 8 (depends on 2)

The receiving device of claim 2, further comprising a demodulator that, after the detection of the leading position of the PPM symbols, demodulates the PPM symbols on a basis of data from the reference position detector.

### Claim 9 (depends on 8)

The receiving device of claim 8, further comprising:
a clock error accumulator that obtains an accumulated value of the clock error on a basis of data from the clock error detector; and
a clock error corrector that performs sample insertion or deletion on an output of the A/D converter, on a basis of data from the clock error accumulator,
wherein the clock generator does not vary the frequency of the clock for sampling, and
wherein the reference position detector, the clock error detector, and the demodulator perform processing on a basis of data from the clock error corrector without using data from the A/D converter.