An oil-lubricated anti-friction bearing is provided for a horizontal arrangement of a rotational axis with a shaft seal that separates a bearing inner chamber, which accommodates rolling bodies, from a bearing outer side, and has a clamping arrangement which acts on the shaft seal from a bearing outer side in order to fix the shaft seal axially. The clamping arrangement has an outlet for oil.

A seal assembly is for sealing between a housing and a rotary shaft includes an annular sealing member coupled with the housing and having inner and outer circumferential surfaces and a plurality of projections extending radially from the outer surface and spaced circumferentially about a central axis. Each projection has first and second axial ends and the plurality of projections define first and second projections. An annular biasing member is disposed about the sealing member outer surface and exerts an inwardly directed force on the sealing member. The biasing member has first and second ends and is arranged on the sealing member with the biasing member first end contacting the second end of each first projection and the biasing member second end contacting the first end of each second projection. As such, the biasing member extends axially and circumferentially between the first and second projections.

A method of sealing a passage in a body with a sealing composition comprising (a) a major proportion of a latex emulsion or colloid; and (b) a minor proportion of lauric acid or a laurate compound; and (c) at least one further selected additive, ideally a latex coagulation inhibitor, wherein said composition is pumped into said passage where it is set or coagulated to form a seal. Advantageously, the laurate compound is ammonium laurate and coagulation is conveniently induced by adjusting pH of the sealing composition from alkaline to acidic pH range. The method is particularly well suited to sealing in faulty formations or sealing sites and may be used in sealing within salt mines which contain brines.

According to an aspect of the present invention, there is provided a seal mechanism, including: a plate spring having a main body portion which has a curved shape and a pair of hook portions which are formed by bending the main body portion; and a seal member having a seal surface and a pair of projecting portions which are formed on an opposite side of the seal surface to catch the hook portions.

Due to increasingly strict requirements and regulations, it is becoming more and more important for piston compressors to reduce the amount of leakage of operating medium through the seal of the piston rod. Conventional seals comprising packing rings and/or packing ring combinations always have a certain amount of leakage, both during operation and when at standstill, which is why they are not usable for certain applications, or the complexity involved in such a seal increases considerably. A further problem involving the seals of piston rods relates to transverse movements by piston rods during which the sealing action of the seal must be maintained. Proposed is, therefore, a sealing arrangement according to the principle of a sealing medium barrier providing that the sealing elements 8, 9 are arranged in radial direction at a distance relative to the radial end of the recess 10 that receives the sealing elements 8, 9.

A cap acting as a grease retention feature and venting system allows crash optimization of a propeller shaft with a plunging constant velocity joint. The cap is located between a constant velocity joint and a tube of the propeller shaft system. The cap includes: a rim sealed against the inner diameter of the constant velocity joint, an interior vent chamber, a vent hole facing the interior components of the constant velocity joint and leading to the vent chamber, and an annular radial groove along the entire circumference connected to the vent chamber. The outer race has a hole perpendicular to the joint axis to complete venting to the atmosphere. In the event of a vehicle crash, the constant velocity internal joint components contact the device, causing the device to dislodge from its fixed position, contact the friction weld curls and fracture at a determined load.

A radial shaft seal for separating two media includes two radial shaft sealing rings each including an axial surface and a sealing lip. The sealing rings are disposed with the axial surfaces facing one another and the sealing lips axially opposed to one another with a space between the sealing lips including a vent. At least one of the sealing rings includes clamping cams configured to grip an inner rim of the other sealing ring so as to join the sealing rings in a form-locking, rear-engaging position relative to each other.

An annular sealing element to seal between metal surfaces for use in flanges, joints, packers and the like, located in oil and gas exploration and production equipment. The sealing element has inner and outer metal deformable surfaces joined at ends, defining an interior volume which is entirely filled with a plastic deformable material. The surfaces are arranged such that on compression of the element from the ends, the element will deform in a controlled manner on a cantilever principle. The volume of filler and the interior volume remain substantially equal during compression so that delamination does not occur. Thus the sealing element provides a seal combining the flexibility of elastomer seals with the integrity of a metal to metal seal.

A hydrodynamic non-contacting seal wherein the sealing surface of a rotatable sealing member is grooved in a spiral pattern such that the depth of the grooves decreases in a direction opposite to the direction of rotation of the rotatable sealing member.

A seal for sealing between two component parts permits a leakage flow of fluid from an upstream side of the seal to a downstream side of the seal. The seal has a jet-producing formation which produces one or more fluid jets that impinge on and thereby restrict the leakage flow.

A bearing isolator assembly comprises an inner support member, an outer support member, a resilient member, an elastomeric ring, and a support cap disposed over a bearing surface defined by the inner support member or the outer support member. A path of travel is defined between the inner support member and the outer support member. The resilient member is disposed between the inner support member and the outer support member and is configured to resist compression between the inner support member and the outer support member within a first portion of the path of travel. The outer support member defines a ring envelope, in which the elastomeric ring is disposed. The inner support member defines a ring compression surface, and the elastomeric ring is configured to resist compression between the ring compression surface of the inner support member and the ring compression surface of the outer support member within a second portion of the path of travel.

Disclosed is a system and method for decreasing airflow and improving ventilation within a tunnel, such as a railroad tunnel, including a path for movement of a vehicle (e.g., train) therethrough. The system has a plurality of air baffles mounted within the tunnel, each device comprising a body and a mounting device. Each mounting device positions each body inside and along the length of the tunnel between the entrance and the exit. The air baffles are configured to restrict airflow at least in part in a longitudinal direction of the tunnel, thereby increasing a relative difference between a vehicle speed and air speed in a tunnel annulus when the vehicle passes through the tunnel. The restriction (e.g., decrease) of airflow in the tunnel reduces the piston effect resulting from the vehicle or train passing through, thus reducing emissions and heat generated by the locomotives in the tunnel.

A speaker diaphragm of the present invention is formed by mixing polylactic acid as a plant-derived resin, bamboo fibers and a natural binder. It is thereby possible to realize a speaker diaphragm capable of obtaining sufficient sound velocity, while having low environmental load and high sound quality.

A multi-layer assembly, such as a sound damping metal laminate used in the automotive industry, having first and second rigid layers and an adhesive layer in between. A retention feature in the form of a raised embossment may be formed in one or more of the rigid layers and may be located near a fastening hole, which accommodates a nut and bolt or some other type of fastening device. The retention feature may impart rigidity and improved stiffness to the multi-layer assembly in the area surrounding the fastening hole, and it may also create a space between the rigid layers that is generally devoid of adhesive from the adhesive layer. This, in turn, can improve the long term performance of the multi-layer assembly by addressing issues such as compression set, spring back and/or stress relaxation. Methods of manufacture and other embodiments are also provided, including ones that accommodate multiple fastening holes, have discontinuous retention features, and use welds in place of nuts and bolts, to name a few.

The attenuation and other optical properties of a medium are exploited to measure a thickness of the medium between a sensor and a target surface. Disclosed herein are various mediums, arrangements of hardware, and processing techniques that can be used to capture these thickness measurements and obtain dynamic three-dimensional images of the target surface in a variety of imaging contexts. This includes general techniques for imaging interior/concave surfaces as well as exterior/convex surfaces, as well as specific adaptations of these techniques to imaging ear canals, human dentition, and so forth.

A communication system for communicating with at least one loudspeaker is described where the loudspeaker is connected to audio equipment over standard two-wire speaker wire operable to carry an audio signal. The communication system includes a master node in electrical communication with a signal path carrying the audio signal between the audio equipment and the loudspeaker, the master node also including an interface with the audio equipment, a data encoder operable to encode data signals, a data transceiver operable to place the data signals onto the audio signal at frequencies above audio frequencies. The communication system also includes at least one slave node in electrical communication with the audio signal and each loudspeaker, the slave node including a data transceiver operable to receive data signals from the master node, a data decoder, and an interface able to communicate with the loudspeaker.

An earphone device includes a housing having a driver unit, and a sound guide tube mounted on a front surface of the housing to protrude from the front surface, in which the sound guide tube is disposed at a position deviated from a center position of the housing.

Measurement data is received from first and second seismic sensors, where the first and second seismic sensors are oriented in opposite directions. Each of the first and second seismic sensors has a sensing element responsive to pressure and particle motion. The signals can be combined to remove the particle motion component of the measurement data and obtain pressure-only data. Alternatively, the signals can be combined to deghost the received measurement data.

A device and attendant method to assist the hearing of a user by being removably connected to and disposing a user's ear in an enhanced hearing orientation. The device includes an elongated base, which may be disposable, and has a sufficient length to be disposed in an operative position behind the user's ear. Opposite ends of the base include an adhesive material secured to a common side thereof, wherein different ones of said opposite ends are respectively disposed and maintained in confronting engagement with a rear surface of the ear and adjacently disposed portion of the user's head. The base further includes biasing capabilities disposed and structured to exert a sufficient, forwardly and outwardly directed force on the user's ear to dispose and maintain it in the enhanced hearing orientation, when the base is in the operative position.

A speaker diaphragm contains a material obtained by adding a cycloolefin polymer resin to a carbon fiber-reinforced liquid crystal polymer. The speaker diaphragm having high sound velocity, a speaker, and a production method of the speaker diaphragm can thereby be obtained.

The present invention relates to an assembly structure of a diaphragm for a microspeaker. The present invention discloses a bonding structure of a diaphragm for a microspeaker, the boding structure comprising: a suspension including a central portion, an outer peripheral portion, and a connecting portion connecting the central portion and the outer peripheral portion; and a side diaphragm including an inner peripheral portion and an outer peripheral portion, which are attached to the central portion and outer peripheral portion of the suspension, respectively, and a dome portion, which projects between the inner peripheral portion and the outer peripheral portion, wherein the suspension and the side diaphragm are attached by thermal compression.

The invention relates to a loudspeaker mounting and adjustment system and method for installing and operating a professional audio system used in a stadium, concert hall or the like. The system comprises a vertical array of loudspeaker cabinets that can be suspended from a ceiling and that enables the horizontal and vertical angle of the sound dispersion field to be adjusted remotely and/or automatically while the system is suspended. Each loudspeaker cabinet is connected to a vertically adjacent loudspeaker cabinet via a pair of levers located on either side of the cabinet that control the angle between adjacent loudspeaker cabinets. A linear actuator is connected to each lever for controlling the lever position. Each loudspeaker cabinet also comprises a waveguide with at least one actuator for modifying the waveguide angle and thus the horizontal angle of the sound dispersion field.

An adaptive speaker panel is provided. The speaker panel can have a speaker opening and a pair of concentric sealing ribs proximate to the speaker opening, the pair of sealing ribs having a first sealing rib and a second sealing rib towards a center of the speaker opening from the first sealing rib. The first sealing rib is first sealing rib dimensioned to seal against a first speaker basket and the second sealing rib dimensioned to seal against a second speaker basket that is smaller than the first speaker basket. Also, the first sealing rib and the second sealing rib are operatively arranged such that without modification to the speaker panel the first speaker basket or the second speaker basket can be attached to and sealed against the panel.

Embodiments of a firearm suppressor are disclosed herein. According to various embodiments, the firearm suppressor can include a housing. The housing can include an outer surface, an inner cavity, and an attachment mechanism that attaches the housing to a barrel of a firearm. The inner cavity can accommodate a baffle. The firearm suppressor also can include a lighting attachment. The lighting attachment can include a power source and a lighting mechanism.

A firearm silencer for suppressing sound intensity generated by the discharge of a firearm, the discharge generating propellant gases, is disclosed. The firearm silencer includes an outer tube. The outer tube is generally hollow and generally cylindrical. The firearm silencer also includes a monolithic baffle stack inserted within the outer tube, and the monolithic baffle stack positions and constrains the outer tube coaxially and axially at a first and second end of the outer tube relative to a first and second end of the monolithic baffle stack using seals and retention seals, with such seals also providing an atmospheric sealing function. The monolithic baffle stack includes a first end that includes a first hole. The monolithic baffle stack also includes a second end that includes a second hole. The second end is located opposite the first end of the monolithic baffle stack. The monolithic baffle stack further includes a plurality of chambers in fluid communication with each other via a plurality of holes and annular void. The monolithic baffle stack also includes a plurality of recesses in fluid communication with the plurality of chambers via a plurality of through holes and annular void. The monolithic baffle stack also further includes plurality of protrusions and plurality of lands within the plurality of chambers where said lands and plurality of holes in chambers form an equivalent cylindrical bore dimension. Moreover, the firearm silencer includes a path extending from the first hole adjacent the first end of the monolithic baffle stack through the first hole adjacent the second end of the monolithic baffle stack. The plurality of chambers, the plurality of recesses, the plurality of through holes, the plurality of protrusions, the plurality of lands, the annular void, and the path are configured to allow propellant gases to travel there through.

There is provided a method for optimizing performance of a multi-transducer earpiece, where the multi-transducer earpiece includes a perpendicular flange that partitions the cross sectional area of the acoustic delivery channel in a manner where mixing of signals from both the high frequency transducer and the mid/low frequency transducer is carried out in the ear canal of a user during reproduction of audio signals.

A horse lead clip assembly for connection between horse tack that includes an upper clasp section with a hook and bolt closure and a lower quick detachable end that allows for the replacement of a broken clip with a new clip portion when excess stress is placed upon the hook of the clasping section. The assembly further includes a sleeve that when actuated laterally, allows for the introduction or removal of a new clasp section from the receiving end of the detachable portion. The assembly provides easy replacement of a broken clip, prevents the user from discarding the rope due to the broken clip, and allows a user to leave the clip hooked on one object while detaching it from the other.

A multi-function pet leash system generally comprises a substantially rigid handle and a substantially rigid tether/carrier engaged with the handle. The tether/carrier may have one or more means for removable tethering and carrying of accessories, whereby with a pet attached to a leash engaged with the tether/carrier, a user may grasp the handle coupled to the leash through the tether/carrier and walk the pet while conveniently carrying one or more accessories. The handle may be disengaged from the tether/carrier and so serve a separate function, alone or in combination with one or more of the accessories.

The present invention relates to an aquarium cleaning apparatus, systems and methods for removing debris from the aquarium, and in particular, a self-contained cleaning apparatus that utilizes a siphon effect created by pouring water in an aquarium tank and/or pulling water out of an aquarium tank, such as via a vacuum. In a preferred embodiment, the siphon operation occurs because of the difference between the water level of the aquarium tank and the vertical height of a spout attached to the top of a vertical tube. Therefore, it is not necessary for the user to immerse their hands in the aquarium water to operate the cleaning device.

The present invention provides treatment apparatus, a fluid application device and methods of removing and applying fluid and relates particularly but not exclusively to an apparatus and method suitable for applying fluid to an elongate object such as a bovine teat or the like and to removing excess fluid. The device includes a holder (28) having a first end (58) and a second end (62) and an interior edge (54) defining a first opening, the first end having a second opening (56); a lower portion (70); and a cassette (30) for insertion into the second opening (56) and including a wiping device (32) having a wiping material (82, 84, 86) extending radially inwardly and extending at least partially across the first opening.

A collar/harness and optionally leash system and method for assembling, using and manufacturing the same is provided. The system may include a single strap including means for connecting attached along the strap at positions predefined to be assembled to form a first loop adapted for use as a collar and a second loop adapted for use as a harness. The first and second loops of the assembled strap may form a figure-eight design.

A dog leash assembly includes (1) an elongated handle portion, (2) a first leash adapter coupled to the first end of the handle portion and having a first leash connector, and (3) a second leash adapter coupled to the second end of the elongated handle portion and a second leash connector, the second leash connector being removably couplable to the first leash connector. A first collar coupling member has a first end that is removably couplable to the first leash connector and/or the second leash connector a second end with a first collar connector that is removably couplable to a dog collar.

A dryer system for a firefighting ensemble comprising a housing having an air intake port and an air outlet port, a forced air assembly including a heater and a blower accommodated within the housing, a plurality of flexible porous hose segments coupled to the air outlet port operable to receive and conduct forced air therefrom, and the plurality of flexible porous hose segments are operable to conduct forced heated air into elements of the firefighting ensemble to speed drying.

A method for printing on a lower surface of a peak of a baseball cap comprising: a) printing an image on the lower surface of the peak when the peak is at an elevated printing temperature and when the peak is in a generally planar configuration; b) allowing the peak to cool to a temperature below an elevated formation temperature; and, c) heating the peak to the elevated formation temperature and applying a non-planar shape to the peak, wherein the peak comprises a deformable insert that is solid at the elevated printing temperature and deformable at the elevated formation temperature.

Disclosed is a paw insertion device. In one embodiment, the device includes two pivotally interconnected arms. Each of the arm can include a paw insertion guide at a distal end. The insertion guides are designed to be inserted into an article of animal footwear. The opposite grip ends of the arms can then be brought together to spread apart the insertion guide and permit the animal paw to be easily positioned within the footwear. A lock subassembly is also included for permitting the insertion device to be locked in the opened position.

A footwear hanger includes a suspension portion for suspending a pair of shoes having toe separators in as side-by-side relation in an upright position, and a pair of support portions connected to, and in mirror symmetrical relationship with, the suspension portion. Each support portion has a plurality of uprights together operative for jointly supporting one of the shoes. The uprights of each support portion are spaced apart from one another and include bound spaces in which the toe separators of the respective shoe are received for holding the shoe upright in the upright position.

A pre-threaded and knotted needle with a length of thread knotted though the eye of the needle and a connection securing the ends of the thread and a sleeve securing a bundle of the thread so that the thread is not tangled until it is released and ready for use The thread is bundle is formed by wrapping it into a bundle and securing a sleeve around the bundle of the thread so that the thread is not tangled until it is released and ready for use. The bundle is released for use by pulling on the needle and the end of the thread to release the bundle of thread.

A biomass pyrolysis process is provided in which biomass feedstock is mixed with a heat carrier. The heat carrier at least partly comprises char. The ratio by weight of biomass to char is in the range 1:1 to 1:20. The process may be carried out by in a screw/auger pyrolysis reactor in which the solid feedstock components are conveyed along the reactor by a first screw. A second screw conveys at least a portion of the solid products of the biomass pyrolysis back to a heat transfer medium input port. Thus, the heat transfer medium includes char from the biomass pyrolysis.

This invention relates to a process for thermochemically transforming biomass or other oxygenated feedstocks into high quality liquid hydrocarbon fuels. In particular, a catalytic hydropyrolysis reactor, containing a deep bed of fluidized catalyst particles is utilized to accept particles of biomass or other oxygenated feedstocks that are significantly smaller than the particles of catalyst in the fluidized bed. The reactor features an insert or other structure disposed within the reactor vessel that inhibits slugging of the bed and thereby minimizes attrition of the catalyst. Within the bed, the biomass feedstock is converted into a vapor-phase product, containing hydrocarbon molecules and other process vapors, and an entrained solid char product, which is separated from the vapor stream after the vapor stream has been exhausted from the top of the reactor. When the product vapor stream is cooled to ambient temperatures, a significant proportion of the hydrocarbons in the product vapor stream can be recovered as a liquid stream of hydrophobic hydrocarbons, with properties consistent with those of gasoline, kerosene, and diesel fuel. Separate streams of gasoline, kerosene, and diesel fuel may also be obtained, either via selective condensation of each type of fuel, or via later distillation of the combined hydrocarbon liquid.

The device and method are provided to increase anhydrosugars yield during pyrolysis of biomass. This increase is achieved by injection of a liquid or gas into the vapor stream of any pyrolysis reactor prior to the reactor condensers. A second feature of our technology is the utilization of sonication, microwave excitation, or shear mixing of the biomass to increase the acid catalyst rate for demineralization or removal of hemicellulose prior to pyrolysis. The increased reactivity of these treatments reduces reaction time as well as the required amount of catalyst to less than half of that otherwise required. A fractional condensation system employed by our pyrolysis reactor is another feature of our technology. This system condenses bio-oil pyrolysis vapors to various desired fractions by differential temperature manipulation of individual condensers comprising a condenser chain.

The present technology describes apparatus, systems, and methods for the thermal decomposition of carbonaceous feedstocks through continuous pyrolysis. A reciprocating reactor is described that includes an inner reactor pipe and an outer reactor pipe. The outer reactor pipe has a first portion that surrounds the inner reactor pipe forming an annulus space, and a second portion that extends beyond the inner reactor pipe and forms a turnaround zone. The inner reactor pipe defines an inner reactor zone that produces partially reacted carbonaceous feedstock, and the annulus space defines an outer reactor zone that produces product gases and solids.

A process for heat treatment of a solid, with a coolant solid, in which a stage for mixing the solid with the pre-heated coolant solid is carried out, with the coolant solid being a solid hydrocarbon. The solid hydrocarbon is ground, before the mixing stage with the solid, to obtain a solid hydrocarbon powder with a grain size of between 20 μm and 300 μm. The solid is ground, before the mixing stage with the coolant solid, to obtain solid pellets with a thickness of between 1 mm and 30 mm, a width of between 1 mm and 40 mm, and a length of between 1 mm and 100 mm. The mixing is carried out at a temperature of between 80° C. and 700° C.

A method for reducing the coking time in the oven area near the door or end wall and for improving coke quality and situation of emissions by compensating for radiation losses through coke oven chamber doors and end walls is described. This compensation is accomplished by varying the height of the coal cake in the environment of the frontal coke oven chamber doors. The variation is achieved both by increasing or decreasing the coal cake over part of the length or over the entire length of the coke oven chamber door. The reduction in the height of the coal cake can be generated by omission of coal or coal compacts, the increase in height can be accomplished by stacking of coal and pressing or adding of coal compacts, with it also being envisaged to omit the pressing cycle so as to obtain a recess with a lower coal cake density which also has less heat radiation.

A device for feeding and controlling secondary air from secondary air ducts into flue gas channels of horizontal coke oven chambers is shown. The flue gas channels are located underneath the coke oven chamber floor on which coal carbonization is realized. The flue gas channels serve for combustion of partly burnt coking gases from the coke oven chamber. The partly burnt gases are burnt with secondary air, thus heating the coke cake also from below to ensure even coal carbonization. Secondary air comes from the secondary air ducts connected to atmospheric air and to the flue gas channels. Controlling elements are mounted in the connecting channels between the flue gas channels and secondary air ducts which can precisely control the air flow into the flue gas channels. Thereby, it is possible to achieve a much more regular heating and heat distribution in coke oven chambers. The actual controlling devices in the connecting channels can be formed by turnable pipe sections, wall bricks, or metal flaps. It is particularly advantageous to utilize a hump-like facility (tabouret) which sits in the secondary air ducts and which is comprised of a tabouret plate with a central opening that is slid under the corresponding embranchment to regulate the gas stream. The controlling mechanism can be actuated manually, electrically, or pneumatically. Thereby, the controlling device can also be automated.

The invention relates to a marking and/or scanning head comprising a plurality of receiving spaces in which individual marking and/or sensing devices can be arranged for marking and/or scanning an object, wherein the receiving spaces are arranged in at least two sub-arrays, wherein at least one sub-array is movable and/or rotatable with regard to at least one other sub-array. The invention further relates to a marking and/or scanning apparatus and a method for operating a marking and/or scanning head or apparatus.

A laser-engraveable flexographic printing precursor or patternable element comprises a laser-engraveable layer having two orthogonal dimensions. This laser-engraveable layer comprises one or more elastomeric resins and non-metallic fibers that are oriented in the laser-engraveable layer predominantly in one of its two orthogonal dimensions. The non-metallic fibers have an average length of at least 0.1 mm and an average diameter of at least 1 μm. The oriented non-metallic fibers reduce curl and shrinkage in the precursor and improve print quality and press life.

The invention pertains to a method and apparatus for preparing a printing form from a precursor, particularly a method and apparatus for preparing the printing form by thermally treating a photosensitive precursor having a photopolymerizable layer. The method and apparatus includes heating the photosensitive precursor to a temperature sufficient to cause a portion of the layer to liquefy, contacting the precursor with a development medium to remove the liquefied material, and supporting a development medium with a core member adjacent an exterior surface of the photosensitive precursor, wherein a compressible collar of a closed-cell foam having a Poisson's ratio of less than 0.4 is disposed between the core member and the development medium.

A device for heating at least one tool that is disposed on the circumference of a rotating cylinder, for example on the circumference of an embossing cylinder. The embossing tool is produced from a magnetizable material and it is fixed to a carrier sleeve that is produced from a non-magnetizable material.

A peak cancellation-crest factor reduction (PC-CFR) device includes a clipping unit configured to output a clipping error signal by clipping amplitude values of a first baseband complex signal based on a predetermined threshold value; a peak value determination unit configured to receive the clipping error signal, and determine a first amplitude value as a peak value when the first amplitude value is greater than a second amplitude value input before the first amplitude value and a third amplitude value input after the first amplitude value among amplitude values of the clipping error signal; a cancellation pulse generator (CPG) allocation unit configured to allocate the peak value to a CPG; and a subtractor configured to subtract a cancellation pulse generated from the CPG from the first baseband complex signal and output a second baseband complex signal with a reduced peak-to-average power ratio (PAPR).

Provided are a preamble symbol generation method and receiving method, and a relevant frequency-domain symbol generation method and a relevant device, characterized in that the method comprises: generating a prefix according to a partial time-domain main body signal truncated from a time-domain main body signal; generating the hyper prefix according to the entirety or a portion of the partial time-domain main body signal; and generating time-domain symbol based on at least one of the cyclic prefix, the time-domain main body signal and the hyper prefix, the preamble symbol containing at least one of the time-domain symbols. Therefore, using the entirety or a portion of a certain length of a time-domain main body signal as a prefix, it is possible to implement coherent detection, which solves the issues of performance degradation with non-coherent detection and differential decoding failure under complex frequency selective fading channels; and generating a hyper prefix based on the entirety or a portion of the above truncated time-domain main body signal enables the generated preamble symbol to have sound fractional frequency offset estimation performance and timing synchronization performance.