Abstract: Multiple receivers may be enabled to receive satellite-based digital audio radio (SDAR) services under a single subscription. For example, an SDAR service provider can enable multiple vehicles, a home-based digital radio, or a portable digital radio, singly or in any combination. Multiple receivers transmit information to each other. One receiver is designated as a primary receiver, and the other receivers are designated as secondary receivers. The SDAR service provider transmits a list of associated secondary receivers to the primary receiver. The primary receiver enables the associated secondary receivers to receive SDAR services by placing them in an authorized state. The secondary receivers must periodically communicate with the primary receiver to remain authorized. A secondary receiver that fails to communicate with the primary receiver within a prescribed time period is switched to an unauthorized state. In this unauthorized state, the secondary receiver no longer performs as an authorized receiver.

Abstract: A method and radio receiver are provided for receiving and deciphering RF signals having encrypted data information relevant to the receiver environment. According to one aspect of the present invention, the receiver includes an input for receiving an RF signal having a data stream including a key selector and encrypted data including a message, and a demodulator for demodulating the data stream and outputting encrypted data including the message. The receiver further includes a data decryption circuit including memory for storing one or more groups of decryption keys based on a characteristic of the receiver environment. The data decryption circuit selects a decryption key based on the key selector and decrypts the message based on the selected decryption key.

Abstract: A method of communicating data in a satellite digital audio radio (SDAR) system includes transmitting two radio frequency digital signals to a SDAR receiver within a motor vehicle. The two signals include substantially identical information. Each signal includes universal data, and also group-specific data that may or may not be relevant to the particular receiver. The group-specific data is located in a predetermined time location within the signals. This method includes combining the group-specific data from one of the two signals with group-specific data from the other signal to create a group-specific output signal. Similarly, the universal data from one of the two signals is combined with universal data from the other signal to create a universal output signal.

Abstract: The present invention provides a receiver for use in a SDAR system, the receiver including a receiving unit having satellite signal detection means for detecting a transmit signal transmitted from a satellite, the transmit signal produced when the transmitter modulates a primary data stream with a secondary data stream on a carrier wave associated with the satellite; and at least one demodulator coupled to the receiving unit and configured to demodulate the transmit signal.

Abstract: A receiver includes a channel decoder select circuit, a plurality of communication channels, at least one maximum ratio combiner circuit, and a forward error correction circuit. The plurality of communication channels receive wireless information from channel demodulators and are in communication with respective channel decoder circuits, which are in communication with the channel decoder select circuit. The at least one maximum ratio combiner circuit receives the wireless information from the plurality of communication channels. The output of the maximum ratio combiner is communicated to the forward error correction circuit, the output of which is communicated to the channel decoder select circuit. A pseudo bit error measurement feedback signal communicated to the maximum ratio combiner from one of the plurality of channel decoder circuits. A method for finding wireless satellite signals that minimizes errors in a receiver system is also disclosed.

Abstract: A catheter has a section of the catheter shaft adjacent its proximal end in which an outer catheter wall and an inner catheter wall define a space therebetween. An electrode is disposed within the space defined between the inner and outer catheter walls. A magnetorheological fluid fills the space between the inner and outer catheter walls. When an electric current is passed through the electrode, the magnetorheological fluid stiffens, causing the section of the catheter shaft adjacent the proximal end to stiffen.

Abstract: A system and method of injecting audio content into a radio system is provided. The method includes the steps of receiving in a radio receiver a first RF signal from an antenna and processing the signal at a select frequency within a radio frequency band. The method also includes the step of providing audio content from an auxiliary device. The method also includes the step of modulating the audio content from the auxiliary device and replicating the modulated signal to generate a replicated RF signal at the multiple frequencies within the radio frequency band. The method further includes the step of injecting the replicated RF signal into the radio receiver.

Abstract: A method and system for communicating satellite digital radio program information for multiple satellite channels is provided. The method includes the steps of providing multiple satellite signals, and providing multiple data frames in each of the satellite signals. The method also includes the steps of providing frame synchronization symbols in each of the data frames, such that the frame synchronization symbols occurring in the satellite signals do not overlap in time with each other. The method also includes the steps of providing multiple data slots within each of the data frames, and providing satellite program information in at least one of the data slots in each data frame. The multiple data slots are positioned within each data frame relative to the frame synchronization symbol of that data frame, such that the data slots containing satellite program information in the multiple satellite signals do not overlap in time with each other.

Abstract: A digital radio receiver system and method are provided for receiving signals from multiple transmission sources and providing dynamic data buffering. The system includes an antenna for receiving signals from multiple sources, a tuner for selecting certain frequency signals, and a digital demodulator for demodulating the tuned selected signals. The system also includes a memory buffer having memory locations and capable of storing data clusters. The system further has a controller for controlling the cluster of data stored in the memory buffer. The controller selects from at least first and second clusters of data, depending strength of signal of a received buffer source.

Abstract: The present invention involves a transmitter for transmitting two levels of data in a hierarchical transmission system. The transmitter has encoders, a modulator, an adjuster, and an up converter. The first encoder has a first output and capable of providing digital information based on a first level of data on the first output. The second encoder has a second output and is capable of providing digital information based on a second level of data on the second output. The modulator is coupled to the first encoder and has I and Q outputs. The adjuster is coupled to the modulator and second encoder and modifies signals on the I and Q outputs of the modulator to produce transmission I and transmission Q outputs. The up converter is coupled to the adjuster and is capable of transmitting broadcast radio signals based on the transmission I and transmission Q outputs. The modulator may include a root raised cosine filter and/or a QPSK modulator.

Abstract: A satellite-based digital audio radio (SDAR) receiver is configured to temporarily store data that may be transmitted to the SDAR receiver at a time inconvenient to the subscriber. A memory arrangement buffers data output by a channel decoder. The SDAR receiver can use the buffered data prior to using any currently transmitted data. The buffered data is associated with buffered timing information that lags behind the current timing information associated with the currently transmitted data. The buffered data is available for use only once before a decryption subsystem receives the current timing information. If the subscriber uses the currently transmitted data, the decryption subsystem receives the current timing information. The decryption subsystem decrypts only data that is associated with timing information that is no earlier than the latest timing information received by the decryption subsystem.

Abstract: This invention provides a receiver for use in a SDAR system which includes a receiving unit having satellite signal detection means for detecting a first transmit signal transmitted from a first communication satellite and a second transmit signal transmitted from a second communication satellite, the first transmit signal produced when the transmitter modulates a primary data stream with a secondary data stream on a first carrier wave associated with the first communication satellite and the second transmit signal produced when the transmitter modulates the primary and secondary data streams on a second carrier wave associated with the second communication satellite, and an encoder re-encodes the primary and the secondary data on a third carrier wave, forming a third transmit signal which is re-transmitted to a receiver using a terrestrial repeater. This invention also provides a method of receiving transmitted data.

Abstract: A braking magnet is attached to the housing of a motor of a motorized component such as a window covering. With this structure the motor is braked from turning under the weight of the window covering when deenergized.

Abstract: A technique for recording information received by a satellite digital audio radio (SDAR) receiver for playback encrypts content of a received SDAR channel using a local key that is unique to the SDAR receiver. The encrypted content is then stored for playback. When selected for playback, the stored encrypted content is decrypted with the local key and provided to the user.

Abstract: A technique for determining a tuning frequency of an audio receiver includes interrupting a received radio frequency (RF) signal at an input of the audio receiver. Next, a modulated audio signal is injected into the input of the audio receiver. Then, it is determined whether the demodulated audio signal is present at an output of the audio receiver. If not, the frequency of the modulated audio signal is changed until the demodulated audio signal is detected at the output of the audio receiver.

Abstract: A method and system of communicating sub-synchronization information into a transmitted digital audio stream and extracting sub-synchronization information from a received digital audio stream is provided. The method includes the steps of having a transmitter introduce sub-synchronization information into a data stream at a period less than that of existing pre-amble signals, and transmitting that data to a receiver. The method further includes the steps of receiving the transmitted data stream in the receiver, extracting the synchronization information, and using the synchronization information to accurately decode the received audio data.

Abstract: A system and method of communicating sub-synchronization information into a transmitted digital audio stream and extracting sub-synchronization information from a received digital audio stream is provided. The method includes the steps of having a transmitter introduce sub-synchronization information into a data stream at a period less than that of existing transmitter pre-amble signals, and transmitting that data to a receiver. The method further includes the steps of receiving the transmitted data stream in the receiver circuitry, extracting the synchronization information, and using the synchronization information to accurately decode the received audio data.

Abstract: An audio system includes a first unit and a second unit. The first unit includes a radio frequency (RF) front-end, a channel decoder, a first wireless interface, a content decoder and a digital-to-analog converter (DAC). The second unit includes a second wireless interface, a source decoder and a content encoder.

Abstract: The present invention provides a receiver for use in a SDAR system, the receiver including a receiving unit having satellite signal detection means for detecting a first transmit signal transmitted from a first communication satellite and a second transmit signal transmitted from a second communication satellite, the first transmit signal produced when the transmitter modulates a primary data stream with a secondary data stream on a first carrier wave associated with the first communication satellite and the second transmit signal produced when the transmitter modulates the primary and secondary data streams on a second carrier wave associated with the second communication satellite; and at least one demodulator coupled to the receiving unit and configured to demodulate the at least one of the first and the second transmit signals.

Abstract: The present invention involves a method for transmitting data using an orthogonal frequency division multiplex (OFDM) transmission system, such as over a terrestrial network used in satellite digital audio radio. A OFDM signal is generated based on first input data. A variation is introduced in the OFDM signal based on second input data to generate a modified OFDM signal which is transmitted. The modified OFDM signal is decoded by performing a demodulation of the modified OFDM signal then a first and second detection to obtain the first input data and the second input data. The introduction of a variance may include introducing an additional phase offset across adjacent OFDM sub-carriers, across adjacent OFDM symbols, an additional phase offset in the OFDM signal, an additional amplitude offset in the OFDM signal, an additional amplitude augmentation in the OFDM signal, and/or a second variation in the first OFDM signal based on third input data.