Abstract: Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

Abstract: Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

Abstract: Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

Abstract: Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

Abstract: Described are systems, methods, apparatuses, and computer program products for wireless in-ear-monitoring (IEM) of audio. A system includes transmitter(s) configured to map orthogonal sub-carriers of a digital signal to narrowband receivers to form receiver-allocated audio channels, modulate the digital signal, and transmit the signal as an ultra-high frequency (UHF) analog carrier wave comprising the orthogonal sub-carriers to the nearby receiver. A narrowband receiver is configured to demodulate and sample the sub-carriers allocated to the receiver. Sub-carriers can be positioned orthogonal to one another in adjacent sub-bands of the frequency domain and beacon symbols and pilot signals can be iteratively provided in the same portion of the frequency domain for each channel. The receiver can use non-data-aided and data-aided approaches for synchronization of the time domain and frequency domain waveforms of the received signal to the transmitted signal prior to sampling the allocated sub-carriers.

Abstract: A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.

Abstract: A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.

Abstract: A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.

Abstract: A method for synchronizing baseband clocks in an OFDMA wireless microphone system is disclosed. An example method includes receiving a plurality of pilot subcarriers from an audio transmitter. The method also includes determining a timing offset estimate based on the pilot subcarriers. The method further includes determining a tuning value by passing the timing offset estimate through a proportional-integral controller. The method still further includes determining a modified reference signal by modifying a reference oscillator based on the tuning value. And the method yet further includes controlling (i) an audio sample clock and (ii) an antenna data clock based on the modified reference signal.

Abstract: The present invention presents a smart dual-view video surveillance system, which carries a smart live-view video and a dedicated recording-view video from each camera to the video recorder. The smart live-view video only carries video data for the visible displayed pixels in its displaying video window and is dedicated for live-view monitoring. The dedicated recording-view video carries the complete video data and is dedicated to video recording and playback.

Abstract: In one aspect the present invention provides a mechanism to carry analog video, digital video and other types of data over a single cable simultaneously between the camera modem and the monitor modem. The analog video has low latency and can be used as real time monitoring, while the digital video is usually compressed high definition video and carried in IP packets. In the camera modem, the analog video is digitized and decoded into digital video, which is further compressed by a near-zero latency video encoder. All types of data, including the compressed analog video and digital video, are multiplexed together to form a single digital stream and transmitted over the cable. In the monitor modem at the other end of the cable, the near-zero latency video stream originated from analog video is de-multiplexed from the single digital downstream, decompressed and finally the corresponding analog video is reconstructed.

Abstract: An automatic gain control (“AGC”) system. The system includes a first multiplier, an envelope detector, a summation module, a filter module, a convergence module, and a feedback module. The convergence module includes a convergence control module and a second multiplier. The feedback module includes an accumulator, a scalar multiplier module, and a third multiplier. The system is configured to adjust or modify its convergence speed according to the state of convergence of the AGC system, and the convergence speed of the AGC system is substantially independent of a signal level of the received signal.

Abstract: Systems and methods of carrier frequency acquisition or recovery in a receiver. The receiver is able to achieve carrier acquisition when a frequency offset is large (e.g., near a decision boundary). The receiver includes a demodulator, an equalizer, and a carrier recovery module. The carrier recovery module includes a decision device and phase detector, a phase error differentiator, a frequency direction confidence module, and a frequency and phase combiner module. The carrier recovery module calculates a phase error differential between a phase error at a first time and a phase error at a second time. Based on the phase error differential, the frequency direction confidence module generates a frequency offset confidence number. The frequency offset confidence number provides an indication of the direction of a frequency offset and a degree of certainty related to a detected direction (e.g., positive or negative) of the frequency offset.

Abstract: An automatic gain control (“AGC”) system. The system includes a first multiplier, an envelope detector, a summation module, a filter module, a convergence module, and a feedback module. The convergence module includes a convergence control module and a second multiplier. The feedback module includes an accumulator, a scalar multiplier module, and a third multiplier. The system is configured to adjust or modify its convergence speed according to the state of convergence of the AGC system, and the convergence speed of the AGC system is substantially independent of a signal level of the received signal.

Abstract: Systems and methods of carrier frequency acquisition or recovery in a receiver. The receiver is able to achieve carrier acquisition when a frequency offset is large (e.g., near a decision boundary). The receiver includes a demodulator, an equalizer, and a carrier recovery module. The carrier recovery module includes a decision device and phase detector, a phase error differentiator, a frequency direction confidence module, and a frequency and phase combiner module. The carrier recovery module calculates a phase error differential between a phase error at a first time and a phase error at a second time. Based on the phase error differential, the frequency direction confidence module generates a frequency offset confidence number. The frequency offset confidence number provides an indication of the direction of a frequency offset and a degree of certainty related to a detected direction (e.g., positive or negative) of the frequency offset.