| 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 |
