Patent application number | Description | Published |
20090010368 | VARIABLE RATE CODING FOR FORWARD LINK - A technique for encoding a signal used in a digital communication system in which individual traffic channel data rates may be adapted to specific channel conditions. In particular, a forward error correction coding rate is adapted for individual channels while at the same time maintaining a fixed block size independent of the FEC coding rate. This allows the system data rate to adapt to the channel conditions experienced by a specific user. Thus, users experiencing good communication conditions with low multipath distortion may be allocated higher capacity, whereas users with significant multipath distortion may make use of lower rate (higher levels of coding) error codes to maintain high quality. Messages are sent from a transmitter to a receiver to inform the receiver of the coding rate implemented at any given point in time. These parameters may be adjusted independent of transmitted power level through the expedient of ensuring that size of a transmitted frame remains constant, while permitting the ability to change FEC coding rates and FEC block sizes. | 01-08-2009 |
20090028114 | STAGGERING FORWARD AND REVERSE WIRELESS CHANNEL ALLOCATION TIMING - An apparatus and method for staggering forward and reverse channel time slot allocation in a wireless communication allows a wireless communication unit, such as a base station processor or a subscriber access unit, to transmit a return message in less than a full time slot interval. Forward and reverse channel allocation occurs as a cycle of time slots occurring at periodic timing intervals. Transmission of a wireless frame carrying a message payload occurs at the beginning of the time slot. Since the forward and reverse channel allocation cycles need not be concurrent, or in phase, these cycles may be staggered with respect to each other. By staggering the forward and reverse channel allocation timing interval, the return message is sent after only a portion of a full timing interval, rather than being delayed up to one complete timing interval. | 01-29-2009 |
20090060005 | Method for using a non-orthogonal pilot signal with data channel interference cancellation - A system and method for encoding/decoding data channels in a CDMA system having data channel interference cancellation, wherein data channel interference cancellation is used to remove unwanted non-orthogonal pilot signal components which are present within a demodulated data signal. This is accomplished by regenerating interference terms with respect to the non-orthogonal pilot signal and subtracting them from the demodulated data signal. | 03-05-2009 |
20090097455 | ACCESS CHANNEL STRUCTURE FOR WIRELESS COMMUNICATION SYSTEM - A technique for efficient implementation of pilot signals on a reverse link in a wireless communication system. An access channel is defined for the reverse link such that within each frame, or epoch, a portion is dedicated to sending only pilot symbols. Another portion of the frame is reserved for sending mostly data symbols; however, within this second portion of the frame, additional pilot symbols are interleaved among the data symbols. The pilot symbol or preamble portion of the access channel frame allows for efficient acquisition of the access signal at the base station, while providing a timing reference for determining the effects of multipath fading. In particular, a pilot correlation filter provides a phase estimate from the pilot symbols in the preamble portion, which is then used to decode the data symbols in the payload portion. An access acquisition portion of the receiver uses the phase estimates provided by the pilot correlation filter to process the output of a data symbol correlation filter. The additional pilot symbols embedded in the payload portion are used in a cross product operation to further resolve the effects of multipath fading. | 04-16-2009 |
20090116469 | Reverse link pilot integrated with block codes - A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes. | 05-07-2009 |
20090135950 | MAXIMIZING DATA RATE BY ADJUSTING CODES AND CODE RATES - The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment. | 05-28-2009 |
20090175249 | ALTERNATE CHANNEL FOR CARRYING SELECTED MESSAGE TYPES - A method for communicating information in a base station is disclosed. A reverse link channel is allocated to be a shared acknowledgement channel for receiving acknowledgement information. Acknowledgement information associated with data payload from a field unit is then received over the shared acknowledgement channel by the base station. | 07-09-2009 |
20090213905 | USE OF ORTHOGONAL OR NEAR ORTHOGONAL CODES IN REVERSE LINK - An apparatus for use with a shared access communication channel is disclosed. The chipping rate of a first group of terminals is determined. Transmissions on the shared access communication channel are encoded using first pseudorandom noise (PN) code and a phase shift at the first chipping rate and an orthogonal spreading code having a chipping rate less than the first chipping rate. The apparatus may receive a feedback channel assignment and may receive an indication of a change in timing on the assigned feedback channel. | 08-27-2009 |
20100011272 | VARIABLE RATE CODING FOR ENABLING HIGH PERFORMANCE COMMUNICATION - A protocol for optimizing the use of coded transmissions such as over wireless links. In this technique, interframes are split into segments selected to be an optimum size according to transmission characteristics of the radio channel. The inverse process is applied at the receiver. Using this scheme, segments containing erroneous data may be present. | 01-14-2010 |
20100202317 | POWER CONTROL PROTOCOL FOR HIGHLY VARIABLE DATA RATE REVERSE LINK OF A WIRELESS COMMUNICATION SYSTEM - A subscriber unit performs power control of a reverse link by sending heartbeat messages to a base station, permitting the base station to determine a reverse link quality report. Using a reverse link quality report message received from the base station, the subscriber unit calculates its reverse power level and maintains the reverse power level during the standby state. | 08-12-2010 |
20100208708 | SYSTEM AND METHOD FOR MAINTAINING WIRELESS CHANNELS OVER A REVERSE LINK OF A CDMA WIRELESS COMMUNICATION SYSTEM - A service option overlay for a CDMA wireless communication in which multiple allocatable subchannels are defined on a reverse link by assigning different code phases of a given long pseudonoise (PN) code to each subchannel. The instantaneous bandwidth needs of each on-line subscriber unit are then met by dynamically allocating none, one, or multiple subchannels on an as needed basis for each network layer connection. The system efficiently provides a relatively large number of virtual physical connections between the subscriber units and the base stations on the reverse link for extended idle periods such as when computers connected to the subscriber units are powered on, but not presently actively sending or receiving data. These maintenance subchannels permit the base station and the subscriber units to remain in phase and time synchronism in an idle mode and also request additional channels. This in turn allows fast acquisition of additional subchannels as needed by allocating new code phase subchannels. Preferably, the code phases of the new channels are assigned according to a predetermined code phase relationship with respect to the code phase of the corresponding maintenance subchannel. | 08-19-2010 |
20110047444 | VARIABLE RATE CODING FOR ENABLING HIGH PERFORMANCE COMMUNICATION - A protocol for optimizing the use of coded transmissions such as over wireless links. In this technique, interframes are split into segments selected to be an optimum size according to transmission characteristics of the radio channel. The inverse process is applied at the receiver. Using this scheme, segments containing erroneous data may be resent. | 02-24-2011 |
20110170493 | METHOD FOR SEARCHING PILOT SIGNALS TO SYNCHRONIZE A CDMA RECEIVER WITH AN ASSOCIATED TRANSMITTER - A method for synchronizing a CDMA receiver to a transmitter when an adaptive antenna is utilized to receive transmitted data, wherein a receiving antenna system is adapted between a 360° reception angle pattern (i.e., an omni-directional pattern) and a fixed reception angle (i.e., a directional pattern) by permitting the receiver to identify a pilot signal having the largest magnitude. The receiver minimizes interference from other pilot signals by steering antenna pattern nulls toward other transmitters. As a result, the time required for the receiver to acquire a valid pilot signal is significantly reduced. | 07-14-2011 |
20110194537 | TIME-SLOTTED DATA PACKETS WITH A PREAMBLE - A method and apparatus are used to support the transmission of data to a user over multiple allocated data channels. Data packets are transmitted in time-slots of the allocated data channels to corresponding target receivers without the need for explicitly assigning particular time-slots to a target user well in advance of transmitting any data packets in the time-slots. Instead, each data packet transmitted in a time-slot includes a header label or preamble indicating to which of multiple possible receivers a data packet is directed. The preamble also preferably includes decoding information indicating how a corresponding data payload of the data packet is to be processed for recapturing transmitted raw data. | 08-11-2011 |
20110216707 | APPLICATION SPECIFIC TRAFFIC OPTIMIZATION IN A WIRELESS LINK - A packet data system such as a TCP/IP network transmits packets containing a variety of data types along links in the network. Packets are transmitted in a stream between nodes interconnected by the links connections which conform to a transport layer protocol such as TCP, UDP, and RSTP, and includes wireless links, which transmit packets using a radio frequency (RF) medium. Typical protocols, however, are usually developed to optimize throughput and minimize data error and loss over wired links, and do not lend themselves well to a wireless link. By examining the data in a packet, performance characteristics such as a port number are determined. The performance characteristics indicate the application type, and therefore, the data type, of the packets carried on the connection. Since certain data types, such as streaming audio and video, are more loss tolerant, determination of the data type is used to compute link control parameters for the wireless link which that are optimal to the type of data being transmitted over the link. | 09-08-2011 |
20120039328 | VARIABLE RATE CODING FOR ENABLING HIGH PERFORMANCE COMMUNICATION - A protocol for optimizing the use of coded transmissions such as over wireless links. In this technique, interframes are split into segments selected to be an optimum size according to transmission characteristics of the radio channel. The inverse process is applied at the receiver. Using this scheme, segments containing erroneous data may be resent. | 02-16-2012 |
20120076113 | TRANSMITTING ACKNOWLEDGEMENT MESSAGES USING A STAGGERED UPLINK TIME SLOT - A downlink communication is transmitted/received in at least one downlink time slot. In response to the received downlink communication, an acknowledgement message is received/transmitted in an uplink time slot a fixed integer number of uplink time slots after transmission/reception of the received downlink communication. The uplink and downlink time slots are staggered by substantially a half of a time slot. | 03-29-2012 |
20120087364 | REVERSE LINK PILOT INTEGRATED WITH BLOCK CODES - A technique for encoding digital communication signals. Data symbols are augmented in pilot symbols inserted at predetermined positions. The pilot augmented sequence is then fed to a deterministic error correction block encoder, such as a turbo product coder, to output a coded sequence. The symbols in the error correction encoded sequence are then rearranged to ensure that the output symbols derived from input pilot symbols are located at regular, predetermined positions. As a result, channel encoding schemes can more easily be used which benefits from power of two length block sizes. | 04-12-2012 |
20120093131 | MINIMAL MAINTENANCE LINK TO SUPPORT SYCHRONIZATION - A method for use in a field unit operable in a wireless communication network. The method includes receiving an indication of a plurality of access identifiers from a base station. The field unit selects an access identifier from the plurality of access identifiers received from the base station. The selected access identifier is associated with a type of field unit request. The field unit transmits the selected access identifier to the base station. The field unit then receives a message from the base station. The message is based on the transmitted selected access identifier. The message contains a timing adjustment that indicates an amount to advance timing. A corresponding field unit apparatus, a base station method, and corresponding base station apparatus is also disclosed. | 04-19-2012 |
20120250798 | MAXIMIZING DATA RATE BY ADJUSTING CODES AND CODE RATES - The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment. | 10-04-2012 |
20120269176 | VARIABLE RATE CODING FOR FORWARD LINK - A forward error correction (FEC) block size is maintained at a constant size. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. Therefore, as the number of information bits per symbol is changed, the number of output bits is always maintained. The scheme permits for a greater flexibility and selection of effective data rates. | 10-25-2012 |
20120289234 | HANDOFF TO BASE STATION HAVING ENHANCED CAPABILITIES - A method and a wireless transmit/receive unit perform a handoff to a target base station having enhanced capabilities. A dual mode manager triggers a capabilities query for information regarding enhanced capability of the target base station, wherein the enhanced capability includes transmission in accordance with a high speed data mode. A generator sends the query to a server connected to the Internet via a first base station not having enhanced capability. The dual mode manager receives from the server via the first base station information regarding the enhanced capability. A handoff to the target base station is initiated by the dual mode manager on a condition that the received information indicates that the target base station has enhanced capability. The dual mode manager deactivates a first mode of operation for communication with the first base station and activates the high speed data mode for communication with the target base station. | 11-15-2012 |
20120307809 | ALTERNATE CHANNEL FOR CARRYING SELECTED MESSAGE TYPES - A method is implemented by a subscriber unit in a wireless communication for establishing a network session. The subscriber unit encodes an acknowledgment message for transmission on a shared reverse link channel to a base station. Acknowledgment information associated with a received session tag at the subscriber unit to the base station is transmitted over the shared reverse link channel, on a condition that the session tag is received from a network server via the base station on a forward link channel and identified by the subscriber unit. The acknowledgment is transmitted on a reverse traffic channel on a condition that the session ID tag is not identified by the subscriber unit. | 12-06-2012 |
20120320901 | USE OF ORTHOGONAL OR NEAR ORTHOGONAL CODES IN REVERSE LINK - An apparatus and method for use with a shared access communication channel is disclosed. A wireless network device receives signals and recovers data from a first plurality of subscriber units and a second plurality of subscriber units in a time interval. Received signals from the first plurality of subscriber units are distinguishable by having unique pseudo noise (PN) sequence with respect to others of the first plurality of subscriber units. Received signals the second plurality of subscriber units are distinguishable by a unique orthogonal sequence with respect to others of the second plurality of subscriber units. Received signals are distinguished between the first and second plurality of subscriber units based on detection of an orthogonal sequence present only in the received signals from the second plurality of subscriber units. | 12-20-2012 |
20130121251 | METHOD FOR SEARCHING PILOT SIGNALS TO SYNCHRONIZE A CDMA RECEIVER WITH AN ASSOCIATED TRANSMITTER - A wireless transmit-receive unit includes an antenna, detection circuitry configured to detect a pseudorandom (PN) offset of a pilot signal received by the antenna while the antenna is adapted to an omnidirectional receive pattern, and monitoring circuitry configured to monitor a received signal strength of the pilot signal as a directional receive pattern of the antenna is steered in order to determine an azimuth angle of the directional pattern that maximizes the pilot signal at the detected PN offset. | 05-16-2013 |
20130176994 | CODED REVERSE LINK MESSAGES FOR CLOSED-LOOP POWER CONTROL OF FORWARD LINK CONTROL MESSAGES - A field unit includes circuitry configured to receive a signal and determine whether the received signal has a predetermined quality; circuitry configured to select a signal from a plurality of signals including a first signal indicating that the field unit is requesting an assignment of resources and the received signal was received with the predetermined quality, a second signal indicating that the field unit is requesting an assignment of resources and the received signal was not received with the predetermined quality, a third signal indicating that the field unit is not requesting an assignment of resources and the received signal was received with the predetermined quality, and a fourth signal indicating that the field unit is not requesting an assignment of resources and the received signal was not received with the predetermined quality; and circuitry configured to transmit the selected signal over a control channel. | 07-11-2013 |
20130242950 | TIME-SLOTTED DATA PACKETS WITH A PREAMBLE - A method and apparatus are used to support the transmission of data to a user over multiple allocated data channels. Data packets are transmitted in timeslots of the allocated data channels to corresponding target receivers without the need for explicitly assigning particular time-slots to a target user well in advance of transmitting any data packets in the time-slots. Instead, each data packet transmitted in a time-slot includes a header label or preamble indicating to which of multiple possible receivers a data packet is directed. The preamble also preferably includes decoding information indicating how a corresponding data payload of the data packet is to be processed for recapturing transmitted raw data. | 09-19-2013 |
20140321441 | MULTI-DETECTION OF HEARTBEAT TO REDUCE ERROR PROBABILITY - A communications system improves performance of detecting a signal having an indication of a request to change communications states by making at least two positive identifications of the request in a given time frame. The system may further improve performance by applying a difference in power levels for a non-request state (i.e., steady state or ‘control hold’ state) versus a request state (i.e., ‘request to change’ state). In one particular application, a base station determines a request to change communications states with a reasonably high probability of detection and a reasonably low probability of false detection. The system has a reduced number of erroneous communications states, such as erroneous traffic channel allocations. The detection technique is compatible with 1xEV-DV systems and I-CDMA systems, but general enough to support systems employing various other communications protocols used in wired and wireless communications systems. | 10-30-2014 |