# Pulse or digital communications

### Patent class list (only not empty are listed)

#### Deeper subclasses:

Class / Patent application number | Description | Number of patent applications / Date published |
---|---|---|

375240000 | BANDWIDTH REDUCTION OR EXPANSION | 9485 |

375259000 | SYSTEMS USING ALTERNATING OR PULSATING CURRENT | 3827 |

375316000 | RECEIVERS | 3494 |

375295000 | TRANSMITTERS | 2339 |

375130000 | SPREAD SPECTRUM | 1730 |

375219000 | TRANSCEIVERS | 1687 |

375224000 | TESTING | 1247 |

375354000 | SYNCHRONIZERS | 1123 |

375229000 | EQUALIZERS | 1044 |

375257000 | CABLE SYSTEMS AND COMPONENTS | 459 |

375211000 | REPEATERS | 205 |

375238000 | PULSE WIDTH MODULATION | 112 |

375286000 | MULTILEVEL | 72 |

375242000 | PULSE CODE MODULATION | 57 |

375239000 | PULSE POSITION, FREQUENCY, OR SPACING MODULATION | 38 |

375256000 | PULSE TRANSMISSION VIA RADIATED BASEBAND | 17 |

375216000 | APPARATUS CONVERTIBLE TO ANALOG | 15 |

375218000 | EARTH OR WATER MEDIUM | 9 |

375353000 | PULSE AMPLITUDE MODULATION | 4 |

20140119486 | APPARATUS FOR IMPROVED ENCODING AND ASSOCIATED METHODS - An apparatus includes an encoder adapted to encode data bits for transmission via a communication link using pulse amplitude modulation (PAM). The encoder includes a logic circuit. The logic circuit is adapted to perform a logic operation on a pattern of bits and the data bits in order to reduce a run-length and/or improve the DC balance of the data bits. | 05-01-2014 |

20110311008 | APPARATUS AND METHOD THEREOF FOR CLOCK AND DATA RECOVERY OF N-PAM ENCODED SIGNALS USING A CONVENTIONAL 2-PAM CDR CIRCUIT - An interface circuit for enabling clock and data recovery (CDR) of N-level pulse amplitude modulation (N-PAM) modulated data streams using a 2-PAM CDR circuit. The circuit comprises a number of N−1 comparators for comparing an input data stream to N−1 configurable thresholds, the input data stream is N-PAM modulated and the N−1 configurable thresholds are N−1 different voltage levels; a number of N−1 of edge detectors respectively connected to the N−1 comparators for detecting transitions from one logic value to another logic value, N is a discrete number greater than two; and a determination unit for determining if the detected transitions is any one of a major transition and a minor transition and asserting a transition signal if only a major transition or a minor transition has occurred, the transition signal is fed into a 2-PAM CDR circuit and utilized for recovering a clock signal of the input data stream. | 12-22-2011 |

20150131765 | COMMUNICATION APPARATUS - A communication apparatus encodes a transmission target data according to a PAM5 mode to generate PAM signals, applies a pulse shaping to the generated PAM signals with a pulse shaping filter to provide pulse-shaped PAM signals, and inputs the pulse-shaped PAM signals into a digital-analog converter. The pulse shaping filter designates a transfer function G(z) as G1(z)=0.667+0.333ẑ−1 that is approximated to G0(z)=(⅔)+(⅓)ẑ−1. | 05-14-2015 |

20140270023 | Low-Complexity Estimation of QAM Symbols and Constellations - Disclosed are methods and structures for soft symbol and variance estimation for QAM constellations including a big-flipping framework and efficient methods for soft symbol estimation and variance estimation for QAM. Disclosed are efficient Gray mapping which provides a much lower complexity, i.e., log N for N-QAM for both squared and non-squared QAM constellations. Also disclosed is an approximation method that avoids multiplications completely while exhibiting only a slight performance degradation. Finally, a low complexity method for variance estimations, particularly second moment estimations for both squared and non-squared QAM constellations with Gray mapping are disclosed. Advantageously—using the disclosed methods—the complexity of the second moment estimation is reduced to O((log N)̂2) for an N-QAM symbol for both squared and non-squared QAM. | 09-18-2014 |

375237000 | PULSE NUMBER MODULATION | 4 |

20080267279 | RFID receiver for miller-encoded signals - A method for decoding a Miller-encoded signal having first and second quadrature components is provided. A Miller sub-carrier signal, synchronized with the Miller-encoded signal, is recovered from the quadrature components. A first, a second, a third, and a fourth half-bit correlation coefficient are calculated from at least one quadrature component and the Miller sub-carrier signal. A cross-correlation result of the first, the second, the third, and the fourth half-bit correlation coefficient is calculated. A value for an output bit is determined from the inverse sign of the cross-correlation result. | 10-30-2008 |

20120275508 | Constellation-Multiplexed Transmitter and Receiver - A device of dynamic communication of information allows, on the average, non-integer bits per symbol transmission, using a compact code set or a partial response decoding receiver. A stream of selectable predetermined integer bits, e.g., k or k+1 data bits, is grouped into a selectable integer number of bit vectors which then are mapped onto corresponding signal constellations forming transmission symbols. Two or more symbols can be grouped and further encoded, so that a symbol is spread across the two or more symbols being communicated. Sequence estimation using, for example, maximum likelihood techniques, as informed by noise estimates relative to the received signal. Each branch metric in computing the path metric of a considered sequence at the receiver is weighted by the inverse of the noise power. It is desirable that the constellation selection, sequence estimation and noise estimation be performed continuously and dynamically. | 11-01-2012 |

20110310953 | Managing Spectra of Modulated Signals in a Communication Network - Information is modulated onto frequency components of a signal. The resulting modulated signal includes at least some redundancy in frequency enabling a portion of the information modulated onto selected frequency components to be recovered from fewer than all of the selected frequency components. Controlling the spectrum of the modulated signal includes enabling the amplitude of at least some frequency components of the modulated signal to be set below a predetermined amplitude used for modulating the information. | 12-22-2011 |

20130208783 | TRANSMITTER AND RECEIVER FOR PULSE DENSITY MODULATED SIGNALS AND SIGNAL PROCESSING METHOD - A transmitter (TX) for transmitting a pulse density modulated signal comprises means (SDM) for generating a pulse density modulated input signal (SI) and an encoder (ENC). The encoder (ENC) comprises a first input for receiving the pulse density modulated input signal (SI) and a second input for receiving additional information (AI) comprising at least one data bit. The encoder (ENC) is configured to generate a multi-bit telegram (TG) on the basis of the additional information (AI), the telegram (TG) comprising a predefined bit-sequence, and to replace an appropriate number of consecutive bits of the input signal (SI) with the telegram (TG) in order to generate an output signal (SO). | 08-15-2013 |