Patent application number | Description | Published |
20090187805 | Turbo decoding module supporting state n metric value normalization operations - A baseband processing module for use within a Radio Frequency (RF) transceiver includes a downlink/uplink interface, TX processing components, a processor, memory, RX processing components, and a turbo decoding module. The RX processing components receive a baseband RX signal from the RF front end, produce a set of IR samples from the baseband RX signal, and transfer the set of IR samples to the memory. The turbo decoding module receives at least one set of IR samples from the memory, forms a turbo code word from the at least one set of IR samples, turbo decodes the turbo code word to produce inbound data, and outputs the inbound data to the downlink/uplink interface. The turbo decoding module performs metric normalization based upon a chosen metric performs error detection operations, and extracts information from a MAC packet that it produces. | 07-23-2009 |
20110002420 | METHOD AND SYSTEM FOR DECODING SINGLE ANTENNA INTERFERENCE CANCELLATION (SAIC) AND REDUNDANCY PROCESSING ADAPTATION USING BURST PROCESS - Aspects of a method and system for decoding single antenna interference cancellation (SAIC) and redundancy processing adaptation using burst process are provided. A wireless receiver may decode bit sequences based on a first decoding algorithm that may utilize redundancy in the data and that may impose physical constraints. The receiver may also decode a received bit sequence based on a second decoding algorithm that utilizes SAIC. Received data may be processed in a burst process portion in either decoding algorithm. Burst processed data from one of the decoding algorithms may be selected based on signal-to-noise ratio and/or received signal level measurements. The selected burst processed data may be communicated to a frame processing portion of the corresponding decoding algorithm. | 01-06-2011 |
20110069795 | Method and System For Decoding Single Antenna Interference Cancellation (SAIC) and Redundancy Processing Adaptation Using Frame Process - Aspects of a method and system for decoding single antenna interference cancellation (SAIC) and redundancy processing adaptation using frame process are provided. A receiver may decode video, voice, and/or speech bit sequences based on a first decoding algorithm that may utilize data redundancy and that may impose physical constraints. The receiver may also decode a bit sequence based on a second decoding algorithm that utilizes SAIC. The first and second decoding algorithms may be adapted to perform in parallel and a decoded received bit sequence may be selected based on a redundancy verification parameter. The first and second decoding algorithms may also be adapted to be performed sequentially where the subsequent decoding operation may be conditioned to the initial decoding operation. Moreover, either the first or the second decoding algorithm may be selected for decoding the received bit sequence. The selection may be based on noise and/or interference measurements. | 03-24-2011 |
20130010901 | Method and System for Decoding Single Antenna Interference Cancellation (SAIC) and Redundancy Processing Adaptation Using Burst Process - Aspects of a method and system for decoding single antenna interference cancellation (SAIC) and redundancy processing adaptation using burst process are provided. A wireless receiver may decode bit sequences based on a first decoding algorithm that may utilize redundancy in the data and that may impose physical constraints. The receiver may also decode a received bit sequence based on a second decoding algorithm that utilizes SAIC. Received data may be processed in a burst process portion in either decoding algorithm. Burst processed data from one of the decoding algorithms may be selected based on signal-to-noise ratio and/or received signal level measurements. The selected burst processed data may be communicated to a frame processing portion of the corresponding decoding algorithm. | 01-10-2013 |
Patent application number | Description | Published |
20090279483 | METHOD AND SYSTEM TO MANAGE WIRELESS COMMUNICATIONS OF HIGH-OCCUPANCY VEHICLES - A system and method for managing wireless communications for a plurality of devices in a high occupancy vehicle is presented. The method comprises steps of creating a global bandwidth usage map across all vehicles, routes, and passengers, transmitting the global bandwidth usage map to a vehicle controller, interpreting the global bandwidth usage map and creating a local usage map, and commanding a wireless concentrator to manage the wireless communications for the devices in accordance with the local usage map. Further, the global map can be created by gathering ticket and route information, obtaining customer productivity data from a network, and parsing obtained data into canonical form. A step of inputting the ticketing information by one of the user, and a ticketing agent can be included. A step of displaying messages using a wireless access application residing on the device can be included. | 11-12-2009 |
20120296968 | System and Method for Group Communications in 3GPP Machine-to-Machine Networks - An inventive system and method for group communication among devices in M2M networks comprises associating one or more of the devices with a gateway having a unique identifier, initiating registration of the devices at an M2M network using the unique identifier of the gateway, providing from the network a temporary identifier to the gateway and associating, in the network, the temporary identifier with the gateway, attaching the devices to the network using the temporary identifier, and communicating information between the network and the device through the gateway. In one aspect, the devices can be classified into sub-groups and each sub-group has a sub-group head that can be attached to the gateway so that the devices can communicate with the network through the sub-group head instead of the gateway. Each sub-group can be associated with a unique temporary identifier, in addition to the temporary identifier associated with the gateway. | 11-22-2012 |
20130094444 | AUTOMATIC PROVISIONING OF AN M2M DEVICE HAVING A WIFI INTERFACE - A method for automatically provisioning a WiFi-equipped machine-to-machine (M2M) device is disclosed. A WiFi M2M gateway identifies a WiFi network identifier broadcast by a powered-on M2M device in WiFi ad hoc mode through a scanning procedure and joins the ad hoc network defined by the M2M device. The WiFi M2M gateway obtains device information (e.g., MAC address) of the M2M device. The WiFi M2M gateway transmits a command to the M2M device to switch from ad hoc mode to infrastructure mode. The WiFi M2M gateway registers the M2M device with an M2M server associated with a service provider based on the device information of the M2M device. The WiFi M2M gateway receives a fully qualified domain name (FQDN) associated with the M2M device from the M2M server. | 04-18-2013 |
Patent application number | Description | Published |
20090215612 | Aromatic hydrogenation catalysts - An MCM-41 catalyst having a crystalline framework containing SiO | 08-27-2009 |
20100147741 | High activity MTT framework type molecular sieves - A process is described of producing an MTT framework type molecular sieve by crystallizing a mixture capable of forming said molecular sieve, wherein the mixture comprises sources of alkali or alkaline earth metal (M), an oxide of trivalent element (X), an oxide of tetravalent element (Y), water and a directing agent (R) of the formula (CH | 06-17-2010 |
20100147747 | Dewaxing catalysts and processes - A process for dewaxing a waxy component-containing hydrocarbon feedstock comprises contacting the feedstock under dewaxing conditions with a catalyst system comprising ZSM-48 and a molecular sieve of the MTT framework type. | 06-17-2010 |
20100187155 | Integrated hydrocracking and dewaxing of hydrocarbons - An integrated process for producing naphtha fuel, diesel fuel and/or lubricant base oils from feedstocks under sour conditions is provided. The ability to process feedstocks under higher sulfur and/or nitrogen conditions allows for reduced cost processing and increases the flexibility in selecting a suitable feedstock. The sour feed can be delivered to a catalytic dewaxing step without any separation of sulfur and nitrogen contaminants, or a high pressure separation can be used to partially eliminate contaminants. The integrated process includes an initial hydrotreatment, hydrocracking, catalytic dewaxing of the hydrocracking effluent, and an option final hydrotreatment. | 07-29-2010 |
20100187156 | Sour service hydroprocessing for lubricant base oil production - An integrated process for producing lubricant base oils from feedstocks under sour conditions is provided. The ability to process feedstocks under higher sulfur conditions allows for reduced cost processing and increases the flexibility in selecting a suitable feedstock. The sour feed can be delivered to a catalytic dewaxing step without any separation of sulfur and nitrogen contaminants, or a high pressure separation can be used to partially eliminate contaminants. | 07-29-2010 |
20100280290 | "METHOD OF MAKING M41S FAMILY MOLECULAR SIEVE" - This disclosure relates to a novel method of making and recovering M41S family molecular sieve materials using synthesis mixtures having high solids-content and without a purification step. The solids-content, for example, is in a range from about 20 wt. % to 50 wt. %. The method also includes the step of mixing at least a portion of the M41S made with another material to form a composition, wherein the amount of said material to be mixed with said M41S product is such that said composition having less than 10 wt. % free fluid. The material mixed with the M41S made includes metal oxides, metal nitrides, metal carbides and mixtures thereof, as well as absorptive material capable of absorbing mother liquor and selected from the group consisting of carbon silica, alumina, titania, zirconia and mixtures thereof. The amount of the wastewater generated by this novel method is reduced by at least 50% to as much as 100% as comparing with conventional method of making M41S materials. By reducing and/or eliminating at least a portion of the wastewater generated in the synthesis product, the new method reduces cost of making of M41S materials and provides a more environmentally-friendly synthesis product. | 11-04-2010 |
20110174684 | Sweet or Sour Service Catalytic Dewaxing in Block Mode Configuration - Sweet and sour lubricant feeds are block and continuous processed to produce lubricant basestocks. Total liquid product yields at a desired pour point are maintained for catalytic dewaxing of both sweet and sour conditions. The desired pour point is achieved for both the sweet and sour feeds by varying the catalytic dewaxing reaction temperature as a function of sulfur content entering the reactor. | 07-21-2011 |
20110192766 | DEWAXING CATALYSTS - A supported catalyst comprises a zeolite having a silica to alumina molar ratio of 500 or less, a first metal oxide binder having a crystallite size greater than 200 Å and a second metal oxide binder having a crystallite size less than 100 Å, wherein the second metal oxide binder is present in an amount less than | 08-11-2011 |
20110315596 | INTEGRATED HYDROCRACKING AND DEWAXING OF HYDROCARBONS - An integrated process for producing naphtha fuel, diesel fuel and/or lubricant base oils from feedstocks under sour conditions is provided. The ability to process feedstocks under higher sulfur and/or nitrogen conditions allows for reduced cost processing and increases the flexibility in selecting a suitable feedstock. The sour feed can be delivered to a catalytic dewaxing step without any separation of sulfur and nitrogen contaminants. The integrated process includes an initial dewaxing of a feed under sour conditions, optional hydrocracking of the dewaxed feed, and a separation to form a first diesel product and a bottoms fraction. The bottoms fraction is then exposed to additional hydrocracking and dewaxing to form a second diesel product and optionally a lubricant base oil product. Alternatively, a feedstock can be hydrotreated, fractionated, dewaxed, and then hydrocracked to form a diesel fuel and a dewaxed, hydrocracked bottoms fraction that is optionally suitable for use as a lubricant base oil. | 12-29-2011 |
20110315599 | INTEGRATED HYDROCRACKING AND DEWAXING OF HYDROCARBONS - An integrated process for producing naphtha fuel, diesel fuel and/or lubricant base oils from feedstocks under sour conditions is provided. The ability to process feedstocks under higher sulfur and/or nitrogen conditions allows for reduced cost processing and increases the flexibility in selecting a suitable feedstock. The sour feed can be delivered to a catalytic dewaxing step without any separation of sulfur and nitrogen contaminants, or with only a high pressure separation so that the dewaxing still occurs under sour conditions. Various combinations of hydrotreating, catalytic dewaxing, hydrocracking, and hydrofinishing can be used to produce fuel products and lubricant base oil products. | 12-29-2011 |
20120316365 | Dehydrogenation Process - In a process for the dehydrogenation of cyclohexanone to produce phenol, a feed comprising cyclohexanone is contacted with a catalyst comprising an inorganic, crystalline, mesoporous support material and a hydrogenation-dehydrogenation component under dehydrogenation conditions effective to convert at least part of the cyclohexanone in the feed into phenol and hydrogen. | 12-13-2012 |
20130172514 | "PROCESS FOR PRODUCING CYCLOALKYLAROMATIC COMPOUNDS" - In a process for producing a cycloalkylaromatic compound, an aromatic compound, hydrogen and at least one diluent are supplied to a hydroalkylation reaction zone, such that the weight ratio of the diluent to the aromatic compound supplied to the hydroalkylation reaction zone is at least 1:100. The aromatic compound, hydrogen and the at least one diluent are then contacted under hydroalkylation conditions with a hydroalkylation catalyst in the hydroalkylation reaction zone to produce an effluent comprising a cycloalkylaromatic compound. | 07-04-2013 |
20130251627 | High Throughput Process for Manufacturing Molecular Sieves - A method of crystallizing a crystalline molecular sieve having a pore size in the range of from about 2 to about 19 Å, said method comprising the steps of (a) providing a mixture comprising at least one source of ions of tetravalent element (Y), at least one hydroxide source (OH | 09-26-2013 |
20140171293 | Xylene Isomerization Process and Catalyst Therefor - The invention concerns a xylenes isomerization process for the production of equilibrium or near-equilibrium xylenes. The process utilizes a catalyst comprising HZSM-5 or MCM-49 and process conditions including a temperature of less than 295° C. and a pressure sufficient to maintain the xylenes in liquid phase. In embodiments, the process can be operated in a continuous mode with ppm levels of dissolved H | 06-19-2014 |
20140194653 | High Throughput Process for Manufacturing Molecular Sieves of MFI Framework Type - A process for converting hydrocarbons comprising the step of contacting said hydrocarbons under conversion conditions with a crystalline molecular sieve having a pore size in the range of from about 2 to about 19 Å, said molecular sieve made by a method comprising the steps of (a) providing a mixture comprising at least one source of ions of tetravalent element (Y), at least one trivalent element hydroxide source (OH | 07-10-2014 |
Patent application number | Description | Published |
20090076317 | Synthesis of high activity ZSM-48 - A process for producing ZSM-48 comprises crystallizing an aqueous reaction mixture comprising at least one source of silica, at least one source of alumina, at least one source of hydroxyl ions, at least one source of diquaternary alkylammonium, R | 03-19-2009 |
20090206004 | Aromatic hydrogenation process - An MCM-41 catalyst having a crystalline framework containing SiO | 08-20-2009 |
20100298598 | Method of Preparing a Molecular Sieve Composition - This disclosure provides a method of preparing a crystalline molecular sieve comprising: (a) providing a reaction mixture comprising at least one source of ions of tetravalent element Y, at least one source of alkali metal hydroxide, water, optionally at least one seed crystal, and optionally at least one source of ions of trivalent element X, the reaction mixture having the following molar composition:
| 11-25-2010 |
20110021855 | Process for Manufacturing MCM-22 Family Molecular Sieves - A method of manufacturing a molecular sieve of the MCM-22 family, said method comprising the steps of (a) providing a mixture comprising at least one source of ions of tetravalent element, at least one source of alkali metal hydroxide, at least one directing-agent (R), water, and optionally at least one source of ions of trivalent element, said mixture having the following mole composition:
| 01-27-2011 |
20110021856 | Method of Preparing a Molecular Sieve Composition - A method of preparing a crystalline molecular sieve is provided, which method comprises
| 01-27-2011 |
20110034749 | Synthesis and use of ZSM-12 - A process is described for synthesizing a porous, crystalline material having the framework structure of ZSM-12 of the formula: | 02-10-2011 |
20110038789 | MCM-22 Family Molecular Sieve Composition - An MCM-22 family molecular sieve having an X-ray diffraction pattern of the as-synthesized MCM-22 family molecular sieve including d-spacing maxima at 12.4±0.25, 3.57±0.07 and 3.42±0.07 Angstroms and at least one peak between 26.6° and 29° (2θ). The peak between 26.6° to 29° (2θ) has a two theta (2θ) of about 26.9°. A method of manufacturing an MCM-22 family molecular sieve, said method comprising the steps of (a) combining at least one silicon source, at least one source of alkali metal hydroxide, at least one directing-agent (R), water, and optionally one aluminum source, to form a mixture having the following mole composition:
| 02-17-2011 |
20110263918 | Xylene Isomerization Process and Catalyst Therefor - The invention concerns a xylenes isomerization process for the production of equilibrium or near-equilibrium xylenes. The process utilizes a catalyst comprising HZSM-5 or MCM-49 and process conditions including a temperature of less than 295° C. and a pressure sufficient to maintain the xylenes in liquid phase. In embodiments, the process can be operated in a continuous mode with ppm levels of dissolved H | 10-27-2011 |
20130026070 | Hydrocracking Catalysts Containing Stabilized Aggregates of Small Crystallites of Zeolite Y Associated Hydrocarbon Conversion Processes - This invention relates to hydrocracking catalysts utilizing stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. This invention also relates to the use of such catalysts in hydrocracking processes for the conversion of heavy oils into lighter fuel products. The invention is particularly suited for the selective production of diesel range products from gas oil range feedstock materials under hydrocracking conditions. | 01-31-2013 |
20130029832 | STABILIZED AGGREGATES OF SMALL CRYSTALLITES OF ZEOLITE Y - This invention relates to stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. | 01-31-2013 |
20130029833 | AGGREGATES OF SMALL CRYSTALLITES OF ZEOLITE Y - This invention relates to aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 μm. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. | 01-31-2013 |
20130096358 | PROCESS FOR PRODUCING PHOSPHORUS MODIFIED ZEOLITE CATALYSTS - In a process for producing a phosphorus-modified zeolite catalyst, an aqueous reaction mixture comprising a source of silica and a source of an organic directing agent effective to direct the synthesis of a desired zeolite is heated at a temperature and for a time sufficient to produce crystals of the desired zeolite. Wet zeolite crystals can then be separated from the reaction mixture and, without removing all the water from the wet zeolite crystals, the zeolite can be converted into the ammonium form by ion exchange, and the crystals can be treated with a phosphorus compound. The phosphorus-treated, ammonium-exchanged zeolite can then be formed into a catalyst to be heated in one or more stages to remove the water and organic directing agent from the zeolite crystals and to convert the zeolite to the hydrogen form. | 04-18-2013 |
20130144100 | SYNTHESIS OF HIGH ACTIVITY LARGE CRYSTAL ZSM-5 - In a process for preparing a high activity, large crystal ZSM-5 type zeolite in the absence of a template, a reaction mixture can be prepared comprising water, a silica source having a surface area less than 150 m | 06-06-2013 |
20130157840 | Molecular Sieve Composition From Pre-Formed Extrudates and Process of Use - This disclosure provides a molecular sieve composition having a first and second crystalline molecular sieve, made by the method comprising: (a) providing a reaction mixture comprising at least one source of ions of tetravalent element Y, at least one source of alkali metal hydroxide, water, optionally at least one seed crystal, and optionally at least one source of ions of trivalent element X, the reaction mixture having the following molar composition: | 06-20-2013 |
20130324760 | Hydrocarbon Conversion Process Using a High Throughpout Process for Manufacturing Molecular Sieves - A method of crystallizing a crystalline molecular sieve having a pore size in the range of from about 2 to about 19 Å, said method comprising the steps of (a) providing a mixture comprising at least one source of ions of tetravalent element (Y), at least one hydroxide source (OH | 12-05-2013 |
20140024523 | Process for Producing Molecular Sieve Materials - In a process for producing a molecular sieve material, water, at least one source of an oxide of a tetravalent and/or a trivalent element and at least one structure directing agent is mixed in a reactor equipped with a mixer having a Froude number of at least 1, to produce a molecular sieve synthesis mixture having a solids content of at least about 20 wt %. The molecular sieve synthesis mixture is heated in the reactor while agitating the mixture with said mixer to form crystals of said molecular sieve material and the molecular sieve crystals are subsequently recovered from the reactor. | 01-23-2014 |
20140024868 | Synthesis and Use of M41S Family Molecular Sieves - A process is described for producing an M41S family molecular sieve. The process comprises preparing a synthesis mixture capable of forming said molecular sieve in a reactor, which is equipped with a mixer having a Froude number of at least 1, said synthesis mixture having a solids content of at least 20 wt %. The synthesis mixture is heated in the reactor while agitating the mixture with said mixer to form a product mixture comprising water and crystals of said molecular sieve material. Thereafter at least part of the water is removed from the product mixture in the reactor so as to decrease the water content of the product mixture inside the reactor by at least 5 wt %. | 01-23-2014 |
20140162866 | FIBER REINFORCED ZEOLITE EXTRUDATES WITH ENHANCED PHYSICAL PROPERTIES - The invention relates to a method of making a reinforced catalytic microporous and/or mesoporous bound composition comprising the steps of: providing a pre-formed catalytic crystalline material; mixing the catalytic crystalline material with water, a metal oxide binder, and a reinforcing glass fiber to form an extrudable composition; extruding the extrudable slurry under conditions sufficient to form the reinforced catalytic bound extrudate; and calcining the reinforced catalytic bound extrudate at a temperature and for a time sufficient to form a calcined reinforced catalytic bound catalyst. Advantageously, the reinforcing glass fiber can have a diameter from 5-100 microns and a length-to-diameter ratio from 300:1-3000:1 and can be present in an amount from about 1-50 parts, based on about 1000 parts combined of catalytic crystalline material and metal oxide binder. | 06-12-2014 |
20140162867 | SYNTHESIS OF ZSM-5 CRYSTALS WITH IMPROVED MORPHOLOGY - Methods are provided for synthesizing crystals having a ZSM-5 framework structure from synthesis mixtures suitable for synthesis of ZSM-12 framework structure crystals in the absence of seed crystals with a ZSM-5 framework structure, such as in the absence of any seed crystals. For synthesis mixtures with a sufficiently high XO | 06-12-2014 |
Patent application number | Description | Published |
20080267326 | Multi-channel receiver with improved AGC - An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, an AGC loop, under the control of an AGC processor, controls the gain of an analog sub-receiver adapted to simultaneously receive multiple signals to achieve a desired AGC setpoint signal intensity from the sub-receiver. Multiple digital demodulators, coupled to the sub-receiver by an analog-to-digital converter (ADC), demodulate the multiple received signals. The AGC controller, based upon which of the received signals are being demodulated, selects the desired AGC setpoint from a table of setpoints. The AGC controller may also provide selective power control to circuitry in the receiver and select the resolution of the ADC. The controller updates the AGC loop with step values selected from a group of values by an AGC control algorithm. Different groups of step values may be used by the controller depending on whether the signals are fading or not. | 10-30-2008 |
20080268798 | Multi-channel receiver with improved AGC - An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, an AGC loop, under the control of an AGC processor, controls the gain of an analog sub-receiver adapted to simultaneously receive multiple signals to achieve a desired AGC setpoint signal intensity from the sub-receiver. Multiple digital demodulators, coupled to the sub-receiver by an analog-to-digital converter (ADC), demodulate the multiple received signals. The AGC controller, based upon which of the received signals are being demodulated, selects the desired AGC setpoint from a table of setpoints. The AGC controller may also provide selective power control to circuitry in the receiver and select the resolution of the ADC. The controller updates the AGC loop with step values selected from a group of values by an AGC control algorithm. Different groups of step values may be used by the controller depending on whether the signals are fading or not. | 10-30-2008 |
20090110047 | DEMODULATOR WITH CONFIGURABLE ADAPTIVE EQUALIZER - An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, the receiver has an adaptive equalizer configurable to operate with QPSK or 8PSK modulated signals. In the equalizer, a slicer table memory responsive to an 8-level quantizer (slicer) and a select signal is configured to map the output of the quantizer into QPSK or 8PSK symbol coordinates depending on whether the QPSK or the 8PSK signal is being received. The slicer table memory may be loaded with the symbol coordinates calculated from data in the 8PSK signal. A pattern matcher determines if the 8PSK or the QPSK signal is being received and asserts the select signal to configure the slicer table memory accordingly. | 04-30-2009 |
20090154613 | TIMING-FREQUENCY OFFSET AND CARRIER-FREQUENCY OFFSET ESTIMATIONS FOR MULTI-CARRIER MODULATED SIGNALS USING PILOT TONES - In one embodiment, a demodulator demodulates a multi-carrier modulated signal having two pilot tones. The demodulator calculates a first phase angle for the first pilot tone and a second phase angle for the second pilot tone based on the time-domain multi-carrier modulated signal. A timing-frequency offset estimate is calculated using the first and second phase angles. Further, a fine carrier-frequency offset estimate is calculated for each pilot tone based on the corresponding phase angle and the timing-frequency offset estimate. Each fine carrier-frequency offset estimate is combined with a coarse estimate and weighted. The weighted estimates are then combined. In further embodiments, the timing-frequency offset estimate is weighted and combined with a weighted timing-frequency offset estimate generated using a cyclic prefix. In yet further embodiments, the weighted carrier-frequency offset estimates are combined with a weighted carrier-frequency offset estimate generated using a cyclic prefix. | 06-18-2009 |
20110188489 | MULTI-CHANNEL RECEIVER WITH IMPROVED AGC - An improved multi-channel receiver for satellite broadcast applications or the like. In an exemplary embodiment, a primary AGC loop controls an analog sub-receiver adapted to simultaneously receive multiple signals. Multiple digital demodulators, coupled to the sub-receiver, demodulate the multiple received signals. Multiple secondary AGC loops, one for each received signal, compensate for variations in demodulated signal strengths caused by the primary AGC loop. A feed-forward AGC compensation technique generates scalar control values for scaling the demodulated signals before the demodulated signals are processed by the secondary AGC loops. This at least partially compensates for gain variations caused by the primary AGC, reducing received signal drop-outs before the secondary AGC loops can compensate for the gain variations. Because of systemic delays in the sub-receiver and the demodulators, the scalar control values are independently timed to be coincident with the variations in the demodulated signal strengths caused by the primary AGC loop. | 08-04-2011 |