IPC Classification

Class code (prefix) Descriptions Number of results
H04B 1/00 TRANSMISSION - Details of transmission systems not characterised by the medium used for transmission
H04B 1/02 Transmitters
H04B 1/03 Constructional details, e.g. casings, housings
H04B 1/04 Circuits
H04B 1/06 Receivers
H04B 1/08 Constructional details, e.g. cabinet
H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
H04B 1/12 Neutralising, balancing, or compensation arrangements
H04B 1/14 Automatic detuning arrangements
H04B 1/16 Circuits
H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line
H04B 1/20 Circuits for coupling gramophone pick-up, recorder output, or microphone to receiver
H04B 1/22 Circuits for receivers in which no local oscillation is generated
H04B 1/24 Circuits for receivers in which no local oscillation is generated the receiver comprising at least one semiconductor device having three or more electrodes
H04B 1/26 Circuits for superheterodyne receivers
H04B 1/28 Circuits for superheterodyne receivers the receiver comprising at least one semiconductor device having three or more electrodes
H04B 1/30 Circuits for homodyne or synchrodyne receivers
H04B 1/034 Portable transmitters
H04B 1/036 Cooling arrangements
H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
H04B 1/40 Circuits
H04B 1/44 Transmit/receive switching
H04B 1/46 Transmit/receive switching by pilot signals
H04B 1/48 Transmit/receive switching in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter
H04B 1/50 Circuits using different frequencies for the two directions of communication
H04B 1/52 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
H04B 1/54 Circuits using the same frequency for two directions of communication
H04B 1/56 Circuits using the same frequency for two directions of communication with provision for simultaneous communication in two directions
H04B 1/58 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
H04B 1/59 Responders; Transponders
H04B 1/60 Supervising unattended repeaters
H04B 1/62 TRANSMISSION - Details of transmission systems not characterised by the medium used for transmission for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
H04B 1/64 Volume compression or expansion arrangements
H04B 1/66 TRANSMISSION - Details of transmission systems not characterised by the medium used for transmission for improving efficiency of transmission
H04B 1/68 TRANSMISSION - Details of transmission systems not characterised by the medium used for transmission for wholly or partially suppressing the carrier or one side band
H04B 1/69 Spread spectrum techniques
H04B 1/71 Interference-related aspects the interference being narrowband interference
H04B 1/72 Circuits or components for simulating antennas, e.g. dummy antennas
H04B 1/74 TRANSMISSION - Details of transmission systems not characterised by the medium used for transmission for increasing reliability, e.g. using redundant or spare channels or apparatus
H04B 1/76 Pilot transmitters or receivers for control of transmission or for equalising
H04B 1/401 Circuits for selecting or indicating operating mode
H04B 1/403 Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency
H04B 1/405 Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency with multiple discrete channels
H04B 1/408 Circuits using the same oscillator for generating both the transmitter frequency and the receiver local oscillator frequency the transmitter oscillator frequency being identical to the receiver local oscillator frequency
H04B 1/525 Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa with means for reducing leakage of transmitter signal into the receiver
H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
H04B 1/707 Spread spectrum techniques using direct sequence modulation
H04B 1/708 Parallel implementation
H04B 1/709 Correlator structure
H04B 1/711 Interference-related aspects the interference being multi-path interference
H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
H04B 1/713 Spread spectrum techniques using frequency hopping
H04B 1/715 Interference-related aspects
H04B 1/717 Pulse-related aspects
H04B 1/719 Interference-related aspects
H04B 1/3805 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving with built-in auxiliary receivers
H04B 1/3816 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving with connectors for programming identification devices
H04B 1/3818 Arrangements for facilitating insertion or removal of identification devices
H04B 1/3822 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving specially adapted for use in vehicles
H04B 1/3827 Portable transceivers
H04B 1/3877 Arrangements for enabling portable transceivers to be used in a fixed position, e.g. cradles or boosters
H04B 1/3883 Arrangements for mounting batteries or battery chargers
H04B 1/3888 Arrangements for carrying or protecting transceivers
H04B 1/7073 Synchronisation aspects
H04B 1/7075 Synchronisation aspects with code phase acquisition
H04B 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
H04B 1/7083 Cell search, e.g. using a three-step approach
H04B 1/7085 Synchronisation aspects using a code tracking loop, e.g. a delay-locked loop
H04B 1/7087 Carrier synchronisation aspects
H04B 1/7093 Matched filter type
H04B 1/7095 Sliding correlator type
H04B 1/7097 Interference-related aspects
H04B 1/7103 Interference-related aspects the interference being multiple access interference
H04B 1/7105 Joint detection techniques, e.g. linear detectors
H04B 1/7107 Subtractive interference cancellation
H04B 1/7113 Determination of path profile
H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
H04B 1/7117 Selection, re-selection, allocation or re-allocation of paths to fingers, e.g. timing offset control of allocated fingers
H04B 1/7136 Arrangements for generation of hop frequencies, e.g. using a bank of frequency sources, using continuous tuning or using a transform
H04B 1/7143 Arrangements for generation of hop patterns
H04B 1/7156 Arrangements for sequence synchronisation
H04B 1/7163 Spread spectrum techniques using impulse radio
H04B 1/7176 Data mapping, e.g. modulation
H04B 1/7183 Synchronisation
H04B 3/00 Line transmission systems
H04B 3/02 Line transmission systems - Details
H04B 3/03 Hybrid circuits
H04B 3/04 Control of transmission; Equalising
H04B 3/06 Control of transmission; Equalising by the transmitted signal
H04B 3/08 Control of transmission; Equalising by the transmitted signal in negative-feedback path of line amplifier
H04B 3/10 Control of transmission; Equalising by pilot signal
H04B 3/11 Control of transmission; Equalising by pilot signal using pilot wire
H04B 3/12 Control of transmission; Equalising by pilot signal in negative-feedback path of line amplifier
H04B 3/14 Control of transmission; Equalising characterised by the equalising network used
H04B 3/16 Control of transmission; Equalising characterised by the negative-impedance network used
H04B 3/18 Control of transmission; Equalising characterised by the negative-impedance network used wherein the network comprises semiconductor devices
H04B 3/20 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
H04B 3/21 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a set of bandfilters
H04B 3/23 Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a replica of transmitted signal in the time domain, e.g. echo cancellers
H04B 3/26 Improving frequency characteristic by the use of loading coils
H04B 3/28 Reducing interference caused by currents induced in cable sheathing or armouring
H04B 3/30 Reducing interference caused by unbalance current in a normally balanced line
H04B 3/32 Reducing cross-talk, e.g. by compensating
H04B 3/34 Reducing cross-talk, e.g. by compensating by addition of balancing components to cable during laying
H04B 3/36 Repeater circuits
H04B 3/38 Repeater circuits for signals in two different frequency ranges transmitted in opposite directions over the same transmission path
H04B 3/40 Artificial lines; Networks simulating a line of certain length
H04B 3/42 Circuits for by-passing of ringing signals
H04B 3/44 Arrangements for feeding power to a repeater along the transmission line
H04B 3/46 Monitoring; Testing
H04B 3/48 Testing attenuation
H04B 3/50 Systems for transmission between fixed stations via two-conductor transmission lines
H04B 3/52 Systems for transmission between fixed stations via waveguides
H04B 3/54 Systems for transmission via power distribution lines
H04B 3/56 Circuits for coupling, blocking, or by-passing of signals
H04B 3/58 Repeater circuits
H04B 3/60 Systems for communication between relatively movable stations, e.g. for communication with lift
H04B 3/462 Testing group delay or phase shift, e.g. timing jitter
H04B 3/466 Testing attenuation in combination with at least one of group delay and phase shift
H04B 3/487 Testing crosstalk effects
H04B 3/493 Testing echo effects or singing
H04B 5/00 Near-field transmission systems, e.g. inductive loop type
H04B 5/02 Near-field transmission systems, e.g. inductive loop type using transceiver
H04B 5/04 Calling systems, e.g. paging system
H04B 5/06 Near-field transmission systems, e.g. inductive loop type using a portable transmitter associated with a microphone
H04B 5/20 characterised by the transmission technique; characterised by the transmission medium
H04B 5/22 Capacitive coupling
H04B 5/24 Inductive coupling
H04B 5/26 using coils
H04B 5/28 using the near field of leaky cables, e.g. of leaky coaxial cables
H04B 5/40 characterised by components specially adapted for near-field transmission
H04B 5/43 Antennas
H04B 5/45 Transponders
H04B 5/48 Transceivers
H04B 5/70 specially adapted for specific purposes
H04B 5/72 for local intradevice communication
H04B 5/73 for taking measurements, e.g. using sensing coils
H04B 5/75 for isolation purposes
H04B 5/77 for interrogation
H04B 5/79 for data transfer in combination with power transfer
H04B 7/00 Radio transmission systems, i.e. using radiation field
H04B 7/01 Reducing phase shift
H04B 7/02 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas
H04B 7/04 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
H04B 7/005 Control of transmission; Equalising
H04B 7/06 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
H04B 7/08 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the receiving station
H04B 7/10 Polarisation diversity; Directional diversity
H04B 7/12 Frequency diversity
H04B 7/14 Relay systems
H04B 7/15 Active relay systems
H04B 7/17 Ground-based stations employing pulse modulation, e.g. pulse code modulation
H04B 7/19 Earth-synchronous stations
H04B 7/22 Scatter propagation systems
H04B 7/24 Radio transmission systems, i.e. using radiation field for communication between two or more posts
H04B 7/26 Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
H04B 7/145 Passive relay systems
H04B 7/155 Ground-based stations
H04B 7/165 Ground-based stations employing angle modulation
H04B 7/185 Space-based or airborne stations
H04B 7/195 Non-synchronous stations
H04B 7/204 Multiple access
H04B 7/208 Frequency-division multiple access
H04B 7/212 Time-division multiple access
H04B 7/216 Code-division or spread-spectrum multiple access
H04B 7/0404 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas the mobile station comprising multiple antennas, e.g. to provide uplink diversity
H04B 7/0408 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas using two or more beams, i.e. beam diversity
H04B 7/0413 MIMO systems
H04B 7/0417 Feedback systems
H04B 7/0426 Power distribution
H04B 7/0452 Multi-user MIMO systems
H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices for antenna weighting
H04B 7/0491 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas using two or more sectors, i.e. sector diversity
H04B 7/0495 Diversity systems; Multi-antenna systems, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas using two or more sectors, i.e. sector diversity using overlapping sectors in the same base station to implement MIMO antennas
H04B 10/00 Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
H04B 10/02 Details
H04B 10/03 Arrangements for fault recovery
H04B 10/04 Transmitters
H04B 10/06 Receivers
H04B 10/07 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
H04B 10/08 Equipment for monitoring, testing or fault measuring
H04B 10/10 Transmission through free space, e.g. through the atmosphere (H04B 10/22, H04B 10/24, H04B 10/30 take precedence);;
H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
H04B 10/12 Transmission through light guides, e.g. optical fibres (H04B 10/22, H04B 10/24, H04B 10/30 take precedence);;
H04B 10/13 using multimodal transmission
H04B 10/14 Terminal stations
H04B 10/16 Repeaters
H04B 10/17 in which processing or amplification is carried out without conversion of the signal from optical form
H04B 10/18 Arrangements for reducing or eliminating distortion or dispersion, e.g. equalisers
H04B 10/20 Arrangements for networking, e.g. bus or star coupling
H04B 10/22 Transmission between two stations which are mobile relative to each other (H04B 10/30 takes precedence);;
H04B 10/24 Bidirectional transmission (H04B 10/22, H04B 10/30 take precedence);;
H04B 10/25 Arrangements specific to fibre transmission
H04B 10/26 using a single light source for both stations involved
H04B 10/27 Arrangements for networking
H04B 10/28 using a single device as a light source or a light receiver
H04B 10/29 Repeaters
H04B 10/30 Transmission systems employing beams of corpuscular radiation (arrangements for handling beams of corpuscular radiation, e.g. focusing, moderating, G21K 1/00)
H04B 10/032 Arrangements for fault recovery using working and protection systems
H04B 10/035 Arrangements for fault recovery using loopbacks
H04B 10/038 Arrangements for fault recovery using bypasses
H04B 10/40 Transceivers
H04B 10/43 Transceivers using a single component as both light source and receiver, e.g. using a photoemitter as a photoreceiver
H04B 10/50 Transmitters
H04B 10/54 Intensity modulation
H04B 10/58 Compensation for non-linear transmitter output
H04B 10/60 Receivers
H04B 10/61 Coherent receivers
H04B 10/63 Homodyne
H04B 10/64 Heterodyne
H04B 10/66 Non-coherent receivers, e.g. using direct detection
H04B 10/67 Optical arrangements in the receiver
H04B 10/69 Electrical arrangements in the receiver
H04B 10/70 Photonic quantum communication
H04B 10/071 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
H04B 10/073 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an out-of-service signal
H04B 10/075 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
H04B 10/077 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using a supervisory or additional signal
H04B 10/079 Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
H04B 10/80 Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups , e.g. optical power feeding or optical transmission through water
H04B 10/85 Protection from unauthorised access, e.g. eavesdrop protection
H04B 10/90 Non-optical transmission systems, e.g. transmission systems employing non-photonic corpuscular radiation
H04B 10/105 specially adapted for satellite links
H04B 10/112 Line-of-sight transmission over an extended range
H04B 10/114 Indoor or close-range type systems
H04B 10/116 Visible light communication
H04B 10/118 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum specially adapted for satellite communication
H04B 10/135 using single mode transmission
H04B 10/142 Coherent homodyne or heterodyne systems
H04B 10/145 Transmitters
H04B 10/148 Receivers
H04B 10/152 Non-coherent direct-detection systems
H04B 10/155 Transmitters
H04B 10/158 Receivers
H04B 10/207 using a star-type coupler
H04B 10/213 using a T-type coupler
H04B 10/255 Self-phase modulation [SPM]
H04B 10/272 Star-type networks
H04B 10/275 Ring-type networks
H04B 10/278 Bus-type networks
H04B 10/291 Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
H04B 10/293 Signal power control
H04B 10/294 Signal power control in a multiwavelength system, e.g. gain equalisation
H04B 10/296 Transient power control, e.g. due to channel add/drop or rapid fluctuations in the input power
H04B 10/297 Bidirectional amplification
H04B 10/299 Signal waveform processing, e.g. reshaping or retiming
H04B 10/508 Pulse generation, e.g. generation of solitons
H04B 10/516 Transmitters - Details of coding or modulation
H04B 10/524 Pulse modulation
H04B 10/532 Polarisation modulation
H04B 10/548 Phase or frequency modulation
H04B 10/556 Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
H04B 10/564 Power control
H04B 10/572 Wavelength control
H04B 10/588 Compensation for non-linear transmitter output in external modulation systems
H04B 10/2507 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
H04B 10/2513 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
H04B 10/2519 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using Bragg gratings
H04B 10/2525 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using dispersion-compensating fibres
H04B 10/2531 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion using spectral inversion
H04B 10/2537 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to scattering processes, e.g. Raman or Brillouin scattering
H04B 10/2543 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to fibre non-linearities, e.g. Kerr effect
H04B 10/2557 Cross-phase modulation [XPM]
H04B 10/2563 Four-wave mixing [FWM]
H04B 10/2569 Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to polarisation mode dispersion [PMD]
H04B 10/2575 Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
H04B 10/2581 Multimode transmission
H04B 10/2587 Arrangements specific to fibre transmission using a single light source for multiple stations
H04B 11/00 Transmission systems employing ultrasonic, sonic or infrasonic waves
H04B 13/00 Transmission systems characterised by the medium used for transmission, not provided for in groups
H04B 13/02 Transmission systems in which the medium consists of the earth or a large mass of water thereon, e.g. earth telegraphy
H04B 14/00 Transmission systems not characterised by the medium used for transmission
H04B 14/02 Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
H04B 14/04 Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse code modulation
H04B 14/06 Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using differential modulation, e.g. delta modulation
H04B 14/08 Transmission systems not characterised by the medium used for transmission characterised by the use of a sub-carrier
H04B 15/00 Suppression or limitation of noise or interference
H04B 15/02 Reducing interference from electric apparatus by means located at or near the interfering apparatus
H04B 15/04 Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
H04B 15/06 Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder by local oscillators of receivers
H04B 17/00 Monitoring; Testing
H04B 17/02 of relay systems
H04B 17/10 Monitoring; Testing of transmitters
H04B 17/11 Monitoring; Testing of transmitters for calibration
H04B 17/12 Monitoring; Testing of transmitters for calibration of transmit antennas, e.g. of amplitude or phase
H04B 17/13 Monitoring; Testing of transmitters for calibration of power amplifiers, e.g. of gain or non-linearity
H04B 17/14 Monitoring; Testing of transmitters for calibration of the whole transmission and reception path, e.g. self-test loop-back
H04B 17/15 Performance testing
H04B 17/16 Test equipment located at the transmitter
H04B 17/17 Detection of non-compliance or faulty performance, e.g. response deviations
H04B 17/18 Monitoring during normal operation
H04B 17/19 Self-testing arrangements
H04B 17/20 Monitoring; Testing of receivers
H04B 17/21 Monitoring; Testing of receivers for correcting measurements
H04B 17/23 Indication means, e.g. displays, alarms or audible means
H04B 17/24 Monitoring; Testing of receivers with feedback of measurements to the transmitter
H04B 17/26 Monitoring; Testing of receivers using historical data, averaging values or statistics
H04B 17/27 Monitoring; Testing of receivers for locating or positioning the transmitter
H04B 17/29 Performance testing
H04B 17/30 Monitoring; Testing of propagation channels
H04B 17/40 Monitoring; Testing of relay systems
H04B 17/309 Measuring or estimating channel quality parameters
H04B 17/318 Received signal strength
H04B 17/327 Received signal code power [RSCP]
H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
H04B 17/345 Interference values
H04B 17/354 Adjacent channel leakage power
H04B 17/364 Delay profiles
H04B 17/373 Predicting channel quality parameters
H04B 17/382 Monitoring; Testing of propagation channels for resource allocation, admission control or handover
H04B 17/391 Modelling the propagation channel