| Class Number |
Class Name |
No. of Patents |
| 375/216 |
Apparatus convertible to analog |
213 |
| 375/217 |
Muting circuit and squelch |
37 |
| 375/240 |
Bandwidth reduction or expansion |
909 |
| 375/241 |
Pulse code modulation |
135 |
| 375/240.01 |
Television or motion video signal |
1017 |
| 375/240.02 |
Adaptive |
340 |
| 375/240.07 |
Feed back |
66 |
| 375/240.06 |
Feed forward |
38 |
| 375/240.03 |
Quantization |
658 |
| 375/240.05 |
Feed back |
208 |
| 375/240.04 |
Feed forward |
138 |
| 375/240.26 |
Associated signal processing |
583 |
| 375/240.27 |
Error detection or correction |
343 |
| 375/240.29 |
Pre/post filtering |
194 |
| 375/240.28 |
Synchronization |
273 |
| 375/240.24 |
Block coding |
695 |
| 375/240.08 |
Feature based |
252 |
| 375/240.09 |
Polygonal approximation |
25 |
| 375/240.1 |
Separate coders |
153 |
| 375/240.11 |
Subband coding |
257 |
| 375/240.12 |
Predictive |
1063 |
| 375/240.15 |
Bidirectional |
393 |
| 375/240.13 |
Intra/inter selection |
231 |
| 375/240.16 |
Motion vector |
1180 |
| 375/240.17 |
Half-pixel refinement |
177 |
| 375/240.14 |
Plural |
350 |
| 375/240.25 |
Specific decompression process |
777 |
| 375/240.21 |
Subsampling |
250 |
| 375/240.18 |
Transform |
306 |
| 375/240.2 |
Discrete cosine |
379 |
| 375/240.19 |
Wavelet |
188 |
| 375/240.23 |
Variable length coding |
265 |
| 375/240.22 |
Vector quantization |
194 |
| 375/257 |
Cable systems and components |
854 |
| 375/258 |
Transformer coupling |
269 |
| 375/218 |
Earth or water medium |
15 |
| 375/229 |
Equalizers |
818 |
| 375/230 |
Automatic |
298 |
| 375/232 |
Adaptive |
1299 |
| 375/236 |
Accumulator or up/down counter |
54 |
| 375/233 |
Decision feedback equalizer |
669 |
| 375/234 |
Fractionally spaced equalizer |
109 |
| 375/235 |
Quadrature channels |
228 |
| 375/231 |
Training period or initial set up |
415 |
| 375/377 |
Miscellaneous |
582 |
| 375/286 |
Multilevel |
293 |
| 375/289 |
Bipolar signal |
80 |
| 375/292 |
Disparity reduction |
104 |
| 375/290 |
Partial response |
109 |
| 375/291 |
Duobinary |
31 |
| 375/293 |
Synchronized |
136 |
| 375/294 |
Phase locked loop |
71 |
| 375/288 |
Transmission line |
98 |
| 375/287 |
With threshold level |
104 |
| 375/353 |
Pulse amplitude modulation |
122 |
| 375/242 |
Pulse code modulation |
440 |
| 375/243 |
Correcting or reducing quantizing errors |
170 |
| 375/244 |
Differential |
207 |
| 375/246 |
Length coding |
109 |
| 375/245 |
Quantizer or inverse quantizer |
209 |
| 375/247 |
Single bit (delta) |
215 |
| 375/249 |
Compand (overload prevention) |
117 |
| 375/250 |
Redundancy removal |
29 |
| 375/251 |
Syllabic |
17 |
| 375/248 |
Nonamplitude delta (area, etc.) |
16 |
| 375/252 |
Plural feedback loops |
45 |
| 375/253 |
Length coding |
122 |
| 375/254 |
Noise or distortion reduction |
295 |
| 375/237 |
Pulse number modulation |
32 |
| 375/239 |
Pulse position, frequency, or spacing modulation |
295 |
| 375/256 |
Pulse transmission via radiated baseband |
84 |
| 375/238 |
Pulse width modulation |
445 |
| 375/316 |
Receivers |
1606 |
| 375/320 |
Amplitude modulation |
103 |
| 375/321 |
Single or vestigial sideband or suppressed carrier |
182 |
| 375/322 |
Angle modulation |
165 |
| 375/323 |
Combined phase shift keyed and frequency shift keyed |
52 |
| 375/334 |
Frequency shift keying |
331 |
| 375/336 |
Minimum shift keying |
86 |
| 375/335 |
More than two frequencies |
89 |
| 375/337 |
Separate mark and space channels |
34 |
| 375/324 |
Particular demodulator |
731 |
| 375/326 |
Carrier recovery circuit or carrier tracking |
711 |
| 375/325 |
Including coherent detector |
146 |
| 375/328 |
Including switching or gating (digital circuits) |
251 |
| 375/327 |
Phase locked loop |
633 |
| 375/329 |
Phase shift keying |
508 |
| 375/333 |
Biphase (manchester code) |
167 |
| 375/330 |
Differential (diphase) |
179 |
| 375/331 |
More than two phases |
151 |
| 375/332 |
Plural phase (>2) |
322 |
| 375/317 |
Automatic baseline or threshold adjustment |
371 |
| 375/319 |
Automatic bias circuit for dc restoration |
170 |
| 375/318 |
Differential amplifier |
112 |
| 375/344 |
Automatic frequency control |
827 |
| 375/345 |
Automatic gain control |
829 |
| 375/346 |
Interference or noise reduction |
1607 |
| 375/350 |
By filtering (e.g., digital) |
1294 |
| 375/347 |
Diversity (frequency or time) |
1248 |
| 375/351 |
Gating, blanking, etc. |
149 |
| 375/348 |
Intersymbol interference |
463 |
| 375/349 |
Plural signal paths in receiver |
738 |
| 375/338 |
Interrupted carrier wave |
14 |
| 375/339 |
Carrier controlling local generator |
30 |
| 375/340 |
Particular pulse demodulator or detector |
1521 |
| 375/343 |
Correlative or matched filter |
1072 |
| 375/342 |
Locating predetermined portion of pulse |
258 |
| 375/341 |
Maximum likelihood decoder or viterbi decoder |
1347 |
| 375/352 |
With electromagnetic relay or solenoid |
13 |
| 375/211 |
Repeaters |
254 |
| 375/214 |
Including pulse regeneration or conversion |
171 |
| 375/215 |
Phase locked loop |
46 |
| 375/212 |
Ring or star configuration |
36 |
| 375/213 |
Testing |
99 |
| 375/130 |
Spread spectrum |
1434 |
| 375/139 |
Chirp |
75 |
| 375/140 |
Direct sequence |
454 |
| 375/141 |
End-to-end transmission system |
482 |
| 375/142 |
Having correlation-type receiver |
618 |
| 375/143 |
Having matched-filter-type receiver |
211 |
| 375/144 |
Having multi-receiver or interference cancellation |
399 |
| 375/145 |
Having specific signaling for code synchronization |
331 |
| 375/147 |
Receiver |
974 |
| 375/150 |
Correlation-type receiver |
1306 |
| 375/151 |
Having saw or charge-transfer device |
55 |
| 375/149 |
Having specific code synchronization |
590 |
| 375/152 |
Matched-filter-type receiver |
403 |
| 375/153 |
Having saw or charge-transfer device |
31 |
| 375/148 |
Multi-receiver or interference cancellation |
983 |
| 375/146 |
Transmitter |
602 |
| 375/132 |
Frequency hopping |
352 |
| 375/133 |
End-to-end transmission system |
261 |
| 375/134 |
Having specific code acquisition or tracking |
175 |
| 375/136 |
Receiver |
295 |
| 375/137 |
Having specific code acquisition or tracking |
137 |
| 375/135 |
Transmitter |
171 |
| 375/131 |
Hybrid form |
80 |
| 375/138 |
Time hopping |
89 |
| 375/354 |
Synchronizers |
1504 |
| 375/358 |
Feedback, receiver to transmitter |
245 |
| 375/362 |
Frequency or phase control using synchronizing signal |
542 |
| 375/369 |
Start - stop |
121 |
| 375/370 |
With asynchronous data |
83 |
| 375/363 |
Synchronization bit insertion into artificially created gaps |
157 |
| 375/364 |
Synchronization signals with unique amplitude, polarity, length, or frequency |
312 |
| 375/365 |
Synchronization word |
443 |
| 375/366 |
Plurality of synchronization words |
167 |
| 375/367 |
Pseudo noise |
374 |
| 375/368 |
Synchronizer pattern recognizers |
600 |
| 375/356 |
Network synchronizing more than two stations |
709 |
| 375/371 |
Phase displacement, slip or jitter correction |
1386 |
| 375/372 |
Elastic buffer |
395 |
| 375/373 |
Phase locking |
696 |
| 375/376 |
Phase locked loop |
2276 |
| 375/374 |
With charge pump or up and down counters |
268 |
| 375/375 |
With frequency detector and phase detector |
516 |
| 375/359 |
Self-synchronizing signal (self-clocking codes, etc.) |
304 |
| 375/361 |
Manchester code or biphase code |
137 |
| 375/360 |
With transition detector |
256 |
| 375/357 |
Synchronization failure prevention |
374 |
| 375/355 |
Synchronizing the sampling time of digital data |
1016 |
| 375/259 |
Systems using alternating or pulsating current |
743 |
| 375/268 |
Amplitude modulation |
92 |
| 375/270 |
Vestigial or single sideband or suppressed carrier |
110 |
| 375/269 |
With phase or frequency shift keying |
138 |
| 375/271 |
Angle modulation |
87 |
| 375/272 |
Frequency shift keying |
179 |
| 375/278 |
Antinoise or distortion |
81 |
| 375/273 |
Combined with phase shift keying |
34 |
| 375/274 |
Minimum shift keying |
64 |
| 375/275 |
More than two frequencies |
63 |
| 375/276 |
One cycle or less per bit |
22 |
| 375/277 |
Vestigial or single sideband, or suppressed carrier |
34 |
| 375/279 |
Phase shift keying |
231 |
| 375/284 |
Antinoise or distortion |
126 |
| 375/282 |
Biphase (manchester codes) |
107 |
| 375/283 |
Differential phase shift keying (diphase) |
134 |
| 375/280 |
More than two phases |
123 |
| 375/281 |
Quaternary |
123 |
| 375/285 |
Antinoise or distortion |
759 |
| 375/260 |
Plural channels for transmission of a single pulse train |
1505 |
| 375/267 |
Diversity |
927 |
| 375/261 |
Quadrature amplitude modulation |
778 |
| 375/262 |
Maximum likelihood decoder or viterbi decoder |
662 |
| 375/264 |
Multilevel |
134 |
| 375/263 |
Partial response |
63 |
| 375/265 |
Trellis encoder or trellis decoder |
636 |
| 375/224 |
Testing |
791 |
| 375/225 |
Data rate |
326 |
| 375/226 |
Phase error or phase jitter |
298 |
| 375/227 |
Signal noise |
302 |
| 375/228 |
With indicator |
143 |
| 375/219 |
Transceivers |
1220 |
| 375/221 |
Loopback mode |
147 |
| 375/222 |
Modems (data sets) |
2013 |
| 375/223 |
Angle modulation |
116 |
| 375/220 |
Transmission interface between two stations or terminals |
608 |
| 375/295 |
Transmitters |
1204 |
| 375/300 |
Amplitude modulation |
146 |
| 375/301 |
Single or vestigial sideband or suppressed carrier |
105 |
| 375/302 |
Angle modulation |
188 |
| 375/303 |
Frequency shift keying |
188 |
| 375/304 |
Antenna tuning with frequency shift |
29 |
| 375/305 |
Minimum shift keying |
86 |
| 375/306 |
One oscillator |
69 |
| 375/307 |
Two or more oscillators |
40 |
| 375/308 |
Phase shift keying |
542 |
| 375/296 |
Antinoise or distortion (includes predistortion) |
1059 |
| 375/297 |
Power amplifier |
604 |
| 375/309 |
Keying circuits |
42 |
| 375/311 |
Automatic |
13 |
| 375/314 |
Including auxiliary control tube |
5 |
| 375/313 |
Key shock or click prevention |
3 |
| 375/315 |
Modulation by absorption of signal, changing antenna dimension or changing antenna impedance |
20 |
| 375/312 |
Power or bias voltage supply keying |
49 |
| 375/310 |
Remote controlled |
16 |
| 375/299 |
Plural diversity |
422 |
| 375/298 |
Quadrature amplitude modulation |
514 |
