Patent application number | Description | Published |
20100074152 | METHOD AND APPARATUS FOR TRANSMITTING DATA IN A TIME DIVISION DUPLEXED (TDD) COMMUNICATION SYSTEM - Techniques to process data for transmission in a time division duplexed (TDD) communication system. In one aspect, the frequency response of a forward link is estimated at a base station based on reverse link transmissions (e.g., pilots) from a terminal Prior to a data transmission on the forward link, the base station determines a reverse transfer function based on the pilots transmitted by the terminal, “calibrates” the reverse transfer function with a calibration function to derive an estimate of a forward transfer function, and preconditions modulation symbols based on weights derived from the forward transfer function. In another aspect, the terminal estimates the “quality” of the forward link and provides this information to the base station. The base station then uses the information to properly code and modulate data prior to transmission such that the transmitted data can be received by the terminal at the desired level of performance. | 03-25-2010 |
20100208639 | APPARATUS AND METHOD FOR TRANSMIT POWER SAVINGS - An apparatus and method for transmit power savings comprising determining a rate of a previous frame; determining if a current frame is an ALWAYS-ON frame, wherein the current frame temporally succeeds the previous frame; and either ignoring every other reverse link power control (RLPC) bits received on a forward power control subchannel (F-PCSCH) or applying every RLPC bits received on the F-PCSCH. In one aspect, the apparatus and method for transmit power savings comprising using a rate determination algorithm (RDA) to determine a rate of a previous frame; detecting a pilot gating pattern at the end of the previous frame; comparing the rate of the previous frame to a threshold; determining if a current frame is an ALWAYS-ON frame; and declaring the current frame to be a 0 bps frame and puncturing the F-PCSCH to a predetermined frequency. | 08-19-2010 |
20100246642 | MULTI-ACCESS HYBRID OFDM-CDMA SYSTEM - In one aspect of a multiple-access OFDM-CDMA system, the data spreading is performed in the frequency domain by spreading each data stream with a respective spreading code selected from a set of available spreading codes. To support multiple access, system resources may be allocated and de-allocated to users (e.g., spreading codes may be assigned to users as needed, and transmit power may be allocated to users). Variable rate data for each user may be supported via a combination of spreading adjustment and transmit power scaling. Interference control techniques are also provided to improve system performance via power control of the downlink and/or uplink transmissions to achieve the desired level of performance while minimizing interference. A pilot may be transmitted by each transmitter unit to assist the receiver units perform acquisition, timing synchronization, carrier recovery, handoff, channel estimation, coherent data demodulation, and so on. | 09-30-2010 |
Patent application number | Description | Published |
20080317158 | TIME-DOMAIN TRANSMIT AND RECEIVE PROCESSING WITH CHANNEL EIGEN-MODE DECOMPOSITION FOR MIMO SYSTEMS - Techniques for processing a data transmission at the transmitter and receiver. In an aspect, a time-domain implementation is provided which uses frequency-domain singular value decomposition and “water-pouring” results to derive time-domain pulse-shaping and beam-steering solutions at the transmitter and receiver. The singular value decomposition is performed at the transmitter to determine eigen-modes (i.e., spatial subchannels) of the MIMO channel and to derive a first set of steering vectors used to “precondition” modulation symbols. The singular value decomposition is also performed at the receiver to derive a second set of steering vectors used to precondition the received signals such that orthogonal symbol streams are recovered at the receiver, which can simplify the receiver processing. Water-pouring analysis is used to more optimally allocate the total available transmit power to the eigen-modes, which then determines the data rate and the coding and modulation scheme to be used for each eigen-mode. | 12-25-2008 |
20090323851 | METHOD AND APPARATUS FOR UTILIZING CHANNEL STATE INFORMATION IN A WIRELESS COMMUNICATION SYSTEM - Techniques for transmitting data from a transmitter unit to a receiver unit in a multiple-input multiple-output (MIMO) communication system. In one method, at the receiver unit, a number of signals are received via a number of receive antennas, with the received signal from each receive antenna comprising a combination of one or more signals transmitted from the transmitter unit. The received signals are processed to derive channel state information (CSI) indicative of characteristics of a number of transmission channels used for data transmission. The CSI is transmitted back to the transmitter unit. At the transmitter unit, the CSI from the receiver unit is received and data for transmission to the receiver unit is processed based on the received CSI. | 12-31-2009 |
20100142638 | MULTIPLEXING OF REAL TIME SERVICES AND NON-REAL TIME SERVICES FOR OFDM SYSTEMS - Transmitter and receiver units for use in an OFDM communications system and configurable to support multiple types of services. The transmitter unit includes one or more encoders, a symbol mapping element, and a modulator. Each encoder receives and codes a respective channel data stream to generate a corresponding coded data stream. The symbol mapping element receives and maps data from the coded data streams to generate modulation symbol vectors, with each modulation symbol vector including a set of data values used to modulate a set of tones to generate an OFDM symbol. The modulator modulates the modulation symbol vectors to provide a modulated signal suitable for transmission. The data from each coded data stream is mapped to a respective set of one or more “circuits”. Each circuit can be defined to include a number of tones from a number of OFDM symbols, a number of tones from a single OFDM symbol, all tones from one or more OFDM symbols, or some other combination of tones. The circuits can have equal size or different sizes. Different circuits can be used for full rate data (e.g., active speech) and low rate data (e.g., silence periods). | 06-10-2010 |
20100166100 | MULTIPLE-INPUT, MULTIPLE-OUTPUT (MIMO) SYSTEMS WITH MULTIPLE TRANSMISSION MODES - Techniques to transmit data on a number of transmission channels in a multi-channel communication system using multiple transmission schemes requiring less channel-state information (CSI). These schemes may include a partial-CSI transmission scheme that transmits a single data stream on each transmit antenna selected for use and a “beam-forming” transmission scheme that allocates all transmit power to a single transmission channel having the best performance. Each transmission scheme may provide good or near-optimum performance for a specific range of operating conditions (or operating SNRs). These multiple transmission schemes may then be combined in a piece-wise fashion to form a “multi-mode” transmission scheme that covers the full range of operating conditions supported by the MIMO system. The specific transmission scheme to be used for data transmission at any given moment would then be dependent on the specific operating condition experienced by the system at that moment. | 07-01-2010 |
20110317671 | MULTIPLE-ACCESS HYBRID OFDM-CDMA SYSTEM - In one aspect of a multiple-access OFDM-CDMA system, data spreading is performed in the frequency domain by spreading each data stream with a respective spreading code selected from a set of available spreading codes. To support multiple access, system resources may be allocated and de-allocated to users (e.g., spreading codes may be assigned to users as needed, and transmit power may be allocated to users). Variable rate data for each user may be supported via a combination of spreading adjustment and transmit power scaling. Interference control techniques are also provided to improve system performance via power control of the downlink and/or uplink transmissions to achieve the desired level of performance while minimizing interference. A pilot may be transmitted by each transmitter unit to assist the receiver units perform acquisition, timing synchronization, carrier recovery, handoff, channel estimation, coherent data demodulation, and so on. | 12-29-2011 |
20130279614 | OFDM COMMUNICATION SYSTEM WITH MULTIPLE OFDM SYMBOL SIZES - Techniques to use OFDM symbols of different sizes to achieve greater efficiency for OFDM systems. The system traffic may be arranged into different categories (e.g., control data, user data, and pilot data). For each category, one or more OFDM symbols of the proper sizes may be selected for use based on the expected payload size for the traffic in that category. For example, control data may be transmitted using OFDM symbols of a first size, user data may be transmitted using OFDM symbols of the first size and a second size, and pilot data may be transmitted using OFDM symbols of a third size or the first size. In one exemplary design, a small OFDM symbol is utilized for pilot and for transport channels used to send control data, and a large OFDM symbol and the small OFDM symbol are utilized for transport channels used to send user data. | 10-24-2013 |
Patent application number | Description | Published |
20120275943 | Pump - A pump for a dialysis machine, the pump having a pump chamber and a deformable membrane actuable to pump a fluid from the pump chamber, the pump chamber being substantially conical such that the membrane is actuated to extend into the conical chamber in order to pump the fluid from the chamber. | 11-01-2012 |
20120279910 | Dialysis Machine - A cartridge for use in a hemodialysis machine, the cartridge comprising a dialysate flow path including a dialyser, the dialysate flow path for delivering a flow of dialysate to the dialyser; a first mixing pump comprising a chamber having a fixed volume between a concave recess and a flexible membrane, said chamber for receiving a predetermined volume of a first dialysate solution base, and a volume of water; a flow balancing pump comprising: a chamber having a fixed volume between a concave recess and a flexible membrane, and inlet through which it receives dialysate; a fluid flow path connecting the first mixing pump to the flow balancing pump; the cartridge further comprising a first check valve having an inlet in fluid communication with said fluid flow path, said check valve configured to open if the pressure in the fluid flow path exceeds a predetermined pressure to allow excess fluid in the fluid flow path to flow through the first check valve to a drain, and to close when the pressure in the fluid flow path falls back below said predetermined pressure. | 11-08-2012 |
20130008854 | DIALYSIS MACHINE CALIBRATION - The invention covers a cartridge for use in a hemodialysis machine, the cartridge comprising a dialysate flow path including a dialyzer, the dialysate flow path for delivering a flow of dialysate through the dialyzer; a mixing pump defining a chamber having volume variable between a maximum volume and a minimum volume for receiving a predetermined volume of a first dialysate solution base, second dialysate solution base, and a volume of water; a first dialysate solution base supply conduit having a first positive displacement pump having a first inlet valve and a first outlet valve associated therewith; a second dialysate solution base supply conduit having a second positive displacement pump having a second inlet valve and a second outlet valve associated therewith; a first and second fluid conduit associated joining respective first and second positive displacement pumps with the mixing pump; and a third fluid conduit for connecting the mixing pump outlet to a dialyzer filter inlet. | 01-10-2013 |
20150027951 | Dialysis Machine - The invention relates to a dialysis machine having improved flow balance. In particular, the invention monitors the pressure of blood entering and leaving a patient's body using several sensors ( | 01-29-2015 |
20150076053 | Dialysis Machine - A hemodialysis machine comprising a dialysate flow path for delivering a flow of dialysate solution through a dialyser, the flow path including a flow balancer for achieving a balance in the dialysate solution flow volume observed between an inlet and an outlet of the dialyser over the course of a treatment, the flow balancer comprising a first flow balance pump having an inlet valve and an outlet valve and a second flow balance pump having an inlet valve and an outlet valve, wherein the flow path further includes a flow restrictor means downstream of the flow balance pumps to reduce the pressure difference across the valves in the dialysate flow path. | 03-19-2015 |
20150129481 | Dialysis Machine - A hemodialysis machine including a main body and a door, the door being capable of opening and closing relative to the main body so as to receive and retain a disposable cartridge therebetween, the machine further including a controller and a pneumatic pump, the cartridge having a chassis with a platen side covered by a first deformable membrane and a door side covered by a second deformable membrane, the chassis and membranes defining a dialysate flow path for delivering a flow of dialysate solution through a dialyser, the main body having a platen for in use sealing against the platen side of the cartridge and the door having an interface plate for in use sealing against the door side of the cartridge, the pneumatic pump being fluidically connected to an interface plate cavity between the interface plate and the cartridge by a pneumatic supply line, the pump being controlled by the controller to selectively generate a vacuum in the platen cavity so as to affix the cartridge to the door prior to operation of the machine. | 05-14-2015 |