Abstract:
A DC translation circuit (200) provides maximum dynamic range in DC level shifting that is temperature and process invariant. The DC translation circuit (200) includes a bandgap reference (202) and current mirror circuit (204) for providing a reference current, Iref. An op-amp circuit (210) receives an AC signal centered about a first DC level, and translates the first DC level into a second DC level using the reference current, a current mirror circuit (208), op-amp circuit (210) and resistor (R2).
Abstract:
A computing device, which may be implemented as an integrated circuit, is constructed of a microprocessor (30) and one or more neural network co-processors (32). The microprocessor (30) normally executes programs which transfer data to the neural network co-processors (32), which are used to compute complicated mathematical functions. Direct Memory Access (DMA) is also used to transfer data. Each neural network co-processor (32) interfaces to the microprocessor in a manner substantially similar to that of a conventional memory device. The co-processor (32) does not require any instructions and is configured to execute mathematical operations simply by being pre-loaded with gating functions and weight values. In addition, the co-processor (32) executes a plurality of arithmetic operations in parallel, and the results of such operations are simply read from the co-processor.
Abstract:
Text may be converted to audible signals, such as speech, by first training a neural network using recorded audio messages (204). To begin the training, the recorded audio messages are converted into a series of audio frames (205) having a fixed duration (213). Then, each audio frame is assigned a phonetic representation (203) and a target acoustic representation, where the phonetic representation (203) is a binary word that represents the phone and articulation characteristics of the audio frame, while the target acoustic representation is a vector of audio information such as pitch and energy. After training, the neural network is used in conversion of text into speech. First, text that is to be converted is translated to a series of phonetic frames of the same form as the phonetic representations (203) and having the fixed duration (213). Then the neural network produces acoustic representations in response to context descriptions (207) that include some of the phonetic frames. The acoustic representations are then converted into a speech wave form by a synthesizer.
Abstract:
In a data transmitter (200), a precision timing signal receiver (201) provides a precise timing signal (203) to an informationnaly responsive comparator (205). The informationally responsive comparator compares an output (211) of a controllable oscillator (209) to the precise timing signal to produce a comparison metric. An output of the informationally responsive compararator, comprising a combination of an information signal (207) and the comparison metric, is then used to control the controllable oscillator.
Abstract:
Electronic devices using microprocessors requiring additional external memory can have security protection for the microprocessors while in an expanded mode of operation. A microprocessor (102) having a security access circuit (112) allows executable code to be stored in a peripheral storage device, such as external EPROM (124), while maintaining protection to the microprocessor EPROM (108) by monitoring if an instruction code is generated from an internal memory source or an external memory source.
Abstract:
Alternate communication services may be provided in a communication system (100) based on the geographic location of a target communication unit. When a service request, which identifies the target communication unit and a particular service, is received by a communication resource controller (101), the communication resource controller (101) ascertains the location of a target communication unit and determines whether the target unit is located within a predefined area. If the target unit (102, 103) is located with the predefined area, the communication resource controller (101) determines whether the particular service requested is prohibited in the predefined area. If the service is prohibited, an alternate service is made available to the initiating communication unit.
Abstract:
A communication system time division multiplexes the use of spreading codes. The communication system accepts information (301, 302) from at least two users and codes each users information utilizing error correction coders (303, 306). The coded information is then time multiplexed by a multiplexer (312) into timeslots. The output of the multiplexer (312) is spread by a common spreading (Walsh) code, scrambled with a pseudo-noise sequence, and conveyed to a modulator for transmission. In this manner, information for two users may be transmitted utilizing only a single spreading (Walsh) code.
Abstract:
In a transmitter (100), circuitry is employed to automatically calibrate errors in a modulated carrier signal. A generator (320) is activated to generate (510) a low frequency square wave for use as data, which is used to generate a modulating signal from which the modulated carrier signal is generated. The modulated carrier signal is down-converted to an intermediate frequency (IF) signal having a steady state IF signal level. The instantaneous IF signal level is compared (545) to the steady state IF signal level to determine (550) whether the instantaneous IF signal level differs from the steady state IF signal level by greater than a predetermined amount, and, when the instantaneous IF signal level differs from the steady state IF signal level by greater than the predetermined amount, the modulating signal is adjusted (560).
Abstract:
A code division multiple access (CDMA) communicating system reduces interference by reducing the encoding rate for selected mobiles. The system (400) primarily uses link related characteristics such as, inter alia, distance measurements, physical resource power, and mobile determined noise, to determine which mobiles require an encoding rate reduction. Once determined, the encoding rate of the determined mobiles is reduced, which in turn reduces self-interference and enhances system capacity.
Abstract:
A radio communication system (10) operates over a sequence of communication channels using a synchronized channel hopping protocol. A first communication device (16) is provided which is capable of communicating over the sequence of communication channels using channel hopping, and which has an operating communication channel. A second communication device (13) is provided, which is capable of determining the operating communication channel and channel hopping parameters of the first communication device (16). The second communication device (13) can communicate over the sequence of communication channels using channel hopping synchronized with the channel hopping of the first communication device (16), while selecting an operating communication channel different from the operating communication channel of the first communication device (16) when both communication devices (13, 16) operate simultaneously.