Abstract:
A method and apparatus determine a response to a control value (316, 320) periodically transmitted by a communication system (Fig. 1) in at least one code word (306, 332) of a frame (302) of data of a communication protocol. The control value (316, 320) is for controlling a receive operation of a communication receiver (122) operating in the communication system. The receiver (122) accepts (404, 504) and stores (406, 506) earlier data from an earlier transmission of the frame (302) of data, and receives (408, 508) current data from a current transmission of the frame (302) of data. The receiver (122) thereafter makes a comparison (414, 512) of the earlier data and the current data, and selects from (a) performing (424, 520) the receive operation in accordance with a current control value received in the current data and (b) performing (418, 516, 528) the receive operation in accordance with an alternative control value, in response to the comparison.
Abstract:
A method of synchronizing a fixed access unit (16) into a time division multiple access (TDMA) system (10). The method includes the steps of receiving a timing advance channel time slot (86) at the fixed access unit (16), sending a message advanced in time by an offset value over the time slot (88), receiving an acknowledgment from the TDMA system (10) that the message was received, and advancing a subsequently transmitted communication based on the offset value.
Abstract:
Error detection and correction of a received message, such as a digitized voice message is achieved by generating (318) interpolated vectors for each error vector corresponding to a codebook index in a sequence of codebook indexes representing parameters of portions of the message. A plurality of error corrected candidate vectors for the vector corresponding to the codebook index in error, are generated (322, 324, 326) by flipping one bit in a sequence of bits representing the codebook index in error. The error corrected candidate vector which has a minimal difference from its corresponding interpolated vector is used (338) to replace the error vector. In the case of digital voice, the vectors are spectral vectors which represent spectral information for a time sample of a voice message. An ordering property of vector components is exploited to detect errors in a received codebook index without parity bits.
Abstract:
A method and apparatus for mitigating effects of multipath fading, interference, and noise in a single sideband (SSB) signal transmitted by a radio communication system and demodulated by a portable subscriber unit (122) utilizing a demodulator (304) compensated by a pilot signal power (406). The apparatus performs the mitigation process by calculating (708) a pilot fading threshold in addition to a muting threshold. When samples of the mean pilot signal power fall below the fading threshold, the compensation of the demodulated signal is adjusted (714). In addition, when the mean analog message signal power falls below the muting threshold, the samples included in the predetermined portion of the message are muted (718).
Abstract:
A method and system for L1 norm operation are provided. An instruction is received by the computer processor (490) and the instruction is decoded by decoder (492) to configure an accumulator and processing elements. A sequence of input signals is distributed through a data pipe line (495) to a programmable accumulator. The accumulator (498) sums the input signals to generate an output signal. The L1 norm operation can be performed using the distance between two vectors.
Abstract:
A method and system for an FIR filter are provided. A sequence of input signal is converted to a corresponding sequence of log signals (408). FIR filtering coefficients are then added to each log signal to generate a plurality of term signals (412). The term signals are then converted to inverse-log signals (414), and the inverse-log signals are summed to produce an output signal (416). Log/inverse-log conversions of signals are based on estimating a log/inverse-log function using a second-order polynomial.
Abstract:
A taut armature resonant impulse transducer (100) includes an armature (12), an electromagnetic driver (24, 26) and a magnetic motional mass (18). The armature includes upper (14, 15) and lower (16, 17) cross-coupled non-linear resonant suspension members, each including planar non-linear springs (62, 72) connected symmetrically about a stepped central region to opposite contiguous planar perimeter regions. The electromagnetic driver (24, 26) is coupled to the upper and lower non-linear resonant suspension members (14, 16), and effects an alternating electromagnetic field. The magnetic motional mass (18) is suspended between the upper (14, 15) and lower (16, 17) cross-coupled non-linear resonant suspension members, and provides an alternating movement in response to the alternating electromagnetic field which is transformed through the upper (14, 15) and lower (16, 17) cross-coupled non-linear resonant suspension members and the electromagnetic driver (24, 26) into motional energy.
Abstract:
The universal multimedia access apparatus (20) accesses a predetermined one of the plurality of multimedia applications (23) using an application-specific module (24) interfaced thereto, the application-specific module (24) being selected from a plurality of application-specific modules. The universal multimedia access apparatus (20) comprises a transceiver (26) and a processing unit (40). The transceiver (26) communicates multimedia information between the multimedia network (22) and the application-specific module (24), and communicates with the multimedia network (22) in any one of a plurality of communication modes. The processing unit (40) is operative to identify the application-specific module (24) interfaced thereto and the predetermined one of the plurality of multimedia applications (23) associated with the application-specific module (24), and operative to command the transceiver (26) to communicate with the multimedia network (22) in a mode associated with the predetermined one of the plurality of multimedia applications (23).
Abstract:
An apparatus and method of detecting a leak in an evaporative emissions system measures vapor flow out of the evaporative emissions system while maintaining a zero pressure difference from inside a fuel tank to atmosphere and provides a reference vapor flow variable dependent on the measurement (317). A pressurized vapor and leak flow variable is measured (323) dependent on measured vapor flow out of the evaporative emissions system while maintaining a pressure difference of 10'' of water from inside the fuel tank to atmosphere. A leak is indicated (327) if a difference between the reference vapor flow variable and the pressurized vapor and leak flow variable is greater than a predetermined leak flow factor.
Abstract:
A receiver (100), transmitter (200) and transceiver (400) in accordance with the present invention overcome the disadvantages of applying adaptive antenna array technology to multi-channel communication systems. Multi-channel radio frequency (RF) signals received via an adaptive antenna array (102) are converted from an analog form to a digital form prior to splitting and processing to recover communication channels contained therein. A number of digital communication signals are digitally combined into a multi-channel digital signal and converted from the digital form to an analog radio frequency form prior to transmission from the adaptive antenna array.