Abstract:
A method of managing power consumption in an electronic circuit, the circuit including a processing unit (101) and a clock circuit (102), the method comprising gating a clock signal (CLK) when the processing unit (101) is in an idle state so that the processing unit (101 ) does not receive clock signals; detecting an event signal at an input to the processing unit (101); latching the event signal while the event signal has not yet been processed by the processing unit (101); ungating the clock signal (CLK) to provide a clock signal to the processing unit; and processing the event signal at the processing unit (101).
Abstract:
A wireless communication network processes composite loop-back signals received at one or more network antennas (54) from a plurality of mobile stations (16), each transmitting an individual, mobile-specific loop-back signal. Using its knowledge of the prior network-transmitted signal(s) from which the mobile stations derive their individual loop-back signals, and its knowledge of the mobile-specific loop-back signal modifications made by each of the mobile stations, the network derives mobile-specific downlink channel information based on processing the composite loop-back signals. That is, use of the mobile-specific loop-back signals enables the network to determine downlink channel estimates as between each participating network antenna and each participating mobile station to be used for transmit signal interference and/or power precompensation, for example. Mobile stations incorporate loop-back signal sample processors used to impart mobile-specific modifications to signal samples obtained from network-transmitted signals. The modified signal samples, thus "imprinted," are then transmitted back to the network.
Abstract:
A channel response is estimated from training symbols that are received over a channel, by determining an initial channel estimate from the training symbols and applying bias to the initial channel estimate to obtain a biased channel estimate. The biased channel estimate is then used for detection.
Abstract:
An access control system includes an access control device, a wireless communication device, and a central controller. The central controller issues authorization codes to the wireless communication device. The wireless communication device is used by an authorized party to enable or activate a protected function secured by an access control device. To enable or activate the protected function, the authorized party uses the wireless communication device to transmit an access request to the access control device, which responds by transmitting an authentication challenge to the wireless communication device. The wireless communication device must transmit a valid authentication response based on the authentication challenge and a valid authorization code stored in its memory. If a valid authentication response is received, the access control device enables or activates the protected function.
Abstract:
A channel response may be estimated from training symbols that are received over a channel, by determining an initial channel estimate from the training symbols and applying bias to the initial channel estimate to obtain a biased channel estimate. The biased channel estimate may then be used to demodulate a signal that is received over the channel.
Abstract:
A transceiver includes a transmitter and a homodyne receiver, wherein the receiver is used to process both antenna-received and antenna-reflected signals. Thus, during a receive mode, for example, the receiver downconverts antenna-received signals to baseband signals, which are then processed to recover receive signal information. Then, during a transmit mode for example, antenna-reflected transmit signals are fed back to the receiver, which is retuned to the desired transmit frequency, and thus downconverts the reflected transmit signals to baseband signals. These baseband signals are then processed to obtain a characterization of impedance mismatch between the transceiver's transmitter and the associated antenna. An adjustable matching network disposed in the transmit signal path thus may be adjusted based on the characterization to reduce the mismatch. Such configurations may be used with either single-band or multi-band embodiments of the transceiver, and the transceiver may be used in both TDMA and CDMA communication systems.
Abstract:
The present invention provides a system for producing a packet delivery schedule, based on desired priority and weighting characterizations of the packet traffic. A number of prioritization schemes are systematically and efficiently reduce to reliable, repeatable schedules. The system accepts two sequences of inputs, based on desired message classification scales. The system begins counting through the sequences, based on their relationships to one another, to determine when to add a member of either scale to a schedule. The system may be designed to terminate the schedule after a fixed number of countings, or may be repeated iteratively as desired. Once a schedule is to completed, the system may continue producing other schedules, utilizing different classification scales, until all classification scales have been comprehended. The resulting schedules are systematically combined to produce a single schedule comprehending all desired classification scales. This system can be implemented in hardware, software, or a combination of both.
Abstract:
The present invention provides a method and apparatus for scheduling message processing. The present invention provides a scheduling mechanism, or scheduler (602), that receives messages (608) and stores the messages (610 or 614) in a first queue (604) or a second queue (606) based, in part, on various criteria associated with the messages. The criteria include message attributes, such as message priority, virtual private network ("VPN") classification and destination software function. The first queue (604) can be a first-in-first-out queue, and the to second queue (606) can be a multi-dimensional queue. The scheduler (602) then schedules the queued messages (612 or 616) for processing based, in part, on various operating criteria (618), such as historical operating data, current operating data and anti-starvation criteria. In addition, the scheduler (602) can be programmed to function in a variety of operating modes.
Abstract:
A compressed prefix tree data structure is provided that allows large prefix trees and Virtual Private Network (VPN) trees to be placed in external memory, while minimizing the number of memory reads needed to reach a result. The compressed prefix tree data structure represents one or more bonsai trees, where each bonsai tree is a portion of a prefix tree containing two or more nodes that can be coded into a single data word (codeword). Each codeword is stored in a portion of the external memory (e.g., 16 bytes of DRAM), and retrieved as a unit for processing. Thus, each external DRAM call can retrieve multiple nodes of a prefix tree, reducing the time required for traversing the prefix tree.
Abstract:
First and second classes of broadcast information, which have different repetitive rates, are transmitted in repetitive shared blocks of a Packet Broadcast Control Channel (PBCCH) of a General Packet Radio Service (GPRS) wireless communications system. The first class of broadcast information may be transmitted at a higher repetition rate in the shared blocks of the PBCCH than the second class of broadcast information. The same sequence of broadcast information of the first class may be transmitted in each instance of a shared block of the PBCCH along with successive portions of the broadcast information of the second class. The shared blocks may be evenly spaced apart within the PBCCH.