PTO Manual of Classification for US patents

PTO Manual of Classification for US patents

What follows are the subclasses from one class of the Manual of Classification for US patents. As you scroll through the list and encounter a class/subclass of interest, you can jump back to the top and retrieve patent titles by entering the class/subclass in the box below.


Enter a class/subclass code here to get a list of patent titles. Use any of the following forms:
363-131 121-55A 14-.5
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Class Number: 375
 Class Title: PULSE OR DIGITAL COMMUNICATIONS

Subclass  Subclass
Number    Title

  1       SPREAD SPECTRUM
  3       REPEATERS
  3.1     .Testing
  4       .Including pulse regeneration or conversion
  5       APPARATUS CONVERTIBLE TO ANALOG
  6       EARTH OR WATER MEDIUM
  7       TRANSCEIVERS
  8       .Modems (data sets)
  9       ..Angle modulation
  10      TESTING
  11      EQUALIZERS
  12      .Automatic
  13      ..Training period or initial set up
  14      ..Adaptive
  15      ...Quadrature channels
  16      ...Accumulator or up/down counter
  17      MULTILEVEL
  18      .Partial response
  19      .Disparity reduction
  20      .Synchronized
  21      PULSE NUMBER MODULATION
  22      PULSE WIDTH MODULATION
  23      PULSE POSITION, FREQUENCY, OR SPACING MODULATION
  24      PULSE AMPLITUDE MODULATION
  25      PULSE CODE MODULATION
  26      .Correcting or reducing quantizing errors
  27      .Differential
  28      ..Single bit (delta)
  29      ...Nonamplitude delta (area, etc.)
  30      ...Compand (overload prevention)
  31      ....Redundancy Removal
  32      ....Syllabic
  33      ...Plural feedback loops
  34      .Noise or distortion reduction
  122     BANDWIDTH REDUCTION OR EXPANSION
  35      PULSE TRANSMISSION VIA RADIATED BASEBAND
  36      CABLE SYSTEMS AND COMPONENTS
  37      SYSTEMS USING ALTERNATING OR PULSATING CURRENT
  38      .Plural channels for transmission of a single pulse train
  39      ..Quadrature amplitude modulation
  40      ..Diversity
  41      .Amplitude modulation
  42      ..With phase or frequency shift keying
  43      ..Vestigial or single sideband or suppressed carrier
  44      .Angle modulation
  45      ..Frequency shift keying
  46      ...Combined with phase shift keying
  47      ...Minimum shift keying
  48      ...More than two frequencies
  49      ...One cycle or less per bit
  50      ...Vestigial or single sideband, or suppressed carrier
  51      ...Anti-noise or distortionn
  52      ..Phase shift keying
  53      ...More than two phases
  54      ....Quaternary
  55      ...Biphase (manchester codes)
  56      ...Differential phase shift keying (diphase)
  57      ...Antinoise or distortion
  58      .Antinoise or distortion
  59      TRANSMITTERS
  60      .Antinoise or distortion (includes predistortion)
  61      .Single or vestigial sideband or suppressed carrier
  62      .Frequency shift keying
  63      ..Antenna tuning with frequency shift
  64      ..Minimum shift keying
  65      ..One oscillator
  66      ..Two or more oscillators
  67      .Phase shift keying
  68      .Keying circuits
  69      ..Remote controlled
  70      ..Automatic
  71      ..Power or bias voltage supply keying
  72      ..Key shock or click prevention
  73      ..Including auxiliary control tube
  74      ..Modulation by absorption of signal, changing antenna dimension
             or changing antenna impedance
  75      RECEIVERS
  76      .Automatic baseline or threshold adjustment
  77      .Single or vestigial sideband or suppressed carrier
  78      .Angle modulation
  79      ..Combined phase shift keyed and frequency shift keyed
  80      ..Particular demodulator
  81      ...Phase locked loop
  82      ...Including switching or gating (digital circuits)
  83      ..Phase shift keying
  84      ...Differential (diphase)
  85      ....More than two phases
  86      ...Plural phase (>2)
  87      ...Biphase (manchester code)
  88      ..Frequency shift keying
  89      ...More than two frequencies
  90      ...Minimum shift keying
  91      ...Separate mark and space channels
  92      .Interrupted carrier wave
  93      ..Carrier controlling local generator
  94      .Particular pulse demodulator or detector
  95      ..Locating predetermined portion of pulse
  96      ..Correlative or matched filter
  97      .Automatic frequency control
  98      .Automatic gain control
  99      .Interference or noise reduction
  100     ..Diversity (frequency or time)
  101     ..Intersymbol interference
  102     ..Plural signal paths in receiver
  103     ..By filtering (e.g., digital)
  104     ..Gating, blanking, etc.
  105     .With elctromagnetic relay or solenoid
  106     SYNCHRONIZERS
  107     .Network synchronizing more than two stations
  108     .Synchronization failure preventionn
  109     .Feedback, receiver to transmitter
  110     .Self synchronizing signal (self clocking codes, etc.)
  111     .Frequency or phase control using synchronizing signal
  112     ..Synchronization bit insertion into artificially created gaps
  113     ..Synchronization signals with unique amplitude, polarity,
             length or frequency
  114     ..Synchronization word
  115     ...Pseudo noise
  116     ...Synchronizer pattern recognizers
  117     ..Start - stop
  118     .Phase displacement, slip or jitter correction
  119     ..Phase locking
  120     ...Phase locked loop
  121     MISCELLANEOUS