Abstract: Method and apparatus for generating compact signatures of acoustic signal are disclosed. A method of generating acoustic signal signatures comprises the steps of dividing input signal into multiple frames, computing Fourier transform of each frame, computing difference between non-negative Fourier transform output values for the current frame and non-negative Fourier transform output values for one of previous frames, combining difference values into subgroups, accumulating difference values within a subgroup, combining accumulated subgroup values into groups, and finding an extreme value within each group.

Abstract: Disclosed is an acoustic communication method that includes filtering an audio signal to attenuate a high frequency section of the audio signal; generating a residual signal which corresponds to a difference between the audio signal and the filtered signal; generating a psychoacoustic mask for the audio signal based on a predetermined psychoacoustic model; generating a psychoacoustic spectrum mask by combining the residual signal with the psychoacoustic mask; generating an acoustic communication signal by modulating digital data according to the acoustic signal spectrum mask; and combining the acoustic communication signal with the filtered signal.

Abstract: A diversity receiver configured to receive digital signals, including a first modulator configured to receive a first signal and modulate the first signal to first data, a second modulator configured to receive a second signal and modulate the second signal to second data, a path aligner configured to detect starting points of the first data and the second data and generate a control signal for synchronizing the first data and the second data, and an equalizer/decoder configured to synchronize the first and second data and to generate a signal to noise ratio and an equalizer output by a recursive equalization operation for the diversity signals thus synchronized.

Abstract: An acoustic communication method and device are provided that filter an audio signal to attenuate a high frequency section of the audio signal. A residual signal is generated that corresponds to a difference between the audio signal and the filtered signal. A psychoacoustic mask is generated for the audio signal based on a predetermined psychoacoustic model. A psychoacoustic spectrum mask is generated by combining the residual signal with the psychoacoustic mask, an acoustic communication signal is generating by modulating digital data according to the acoustic signal spectrum mask, the acoustic communication signal is combined with the filtered signal, and radiating, by a speaker, the combined acoustic communication signal and the filtered signal in a form of sound waves.

Abstract: A method and apparatus for providing location information are provided. The method includes receiving data including reference sound information from at least one external device; receiving location information request data including sound information from the mobile device; detecting similar reference sound information to the sound information based on a comparison of the sound information to the reference sound information; determining location in formation of an external device that transmitted the similar reference sound information; and transmitting the determined location information to the mobile device.

Abstract: A method for transmitting, by a mobile device, a data object, is provided, and includes estimating expected transmission times required for transmitting an object between devices by an acoustic communication link and supported radio interfaces, based on a size of the object, transmitting the object through an acoustic communication channel when the link is estimated to provide a shortest expected transmission time, and determining rankings of the radio interfaces according to the expected transmission times when the acoustic communication link does not provide a shortest expected transmission time, transmitting rankings information and configuration information on the supported radio interfaces through the acoustic communication channel by a configuration container, and transmitting the object through a radio interface through which a response is received.

Abstract: A frequency detector includes an error measurement unit measuring a time interval between zero-crossing points of an input signal that is modulated. An error conversion unit quantizes the measured time interval using one of modulation time intervals. An error calculation unit calculates a frequency error based upon a difference between the measured time interval and the quantized time interval. An error generation control unit controls whether to output the frequency error based upon the quantized time interval, the calculated frequency error, and a predetermined critical value.

Abstract: An inter-carrier interference ICI cancellation method of a kth sub-carrier of an orthogonal frequency division multiplexing OFDM receiving signal (k is a natural number greater than 1 and less than or equal to n, n is a number of sub-carriers) includes canceling an inter-carrier interference element produced by at least one sub-carrier among inter-carrier interference elements of the kth sub-carrier by a decision feedback equalization DFE method, and canceling another inter-carrier interference element produced by at least another sub-carrier among inter-carrier interference elements of the kth sub-carrier by a linear minimum mean square error equalization LMMSE method.

Abstract: An orthogonal frequency division multiplexing (OFDM) receiver includes a n average power calculation unit and an output unit. The average power calculation unit calculates and outputs a first average power of a null symbol section of each transmitted frame output from an OFDM transmitter and calculates and outputs second average powers of sub-carriers that correspond to each null symbol section. The output unit compares the first average power and the second average powers, to perform a reciprocal transformation on difference values of the first average power and each of the second average powers based on results of the comparisons, and to store and output reciprocally transformed values as channel state information.

Abstract: An apparatus and method for transmitting and receiving data for a multi-channel digital broadcasting system, using advanced encoding schemes (including sub channels having a regular part and a parity part) but also compatible with the existing digital broadcasting systems. In the transmitting apparatus, a main service channel includes a plurality of sub channels, and at least one of the sub channels contains a regular part generated based on the information data and a parity part corresponding to the regular part.

Abstract: A diversity receiver configured to receive digital signals, including a first modulator configured to receive a first signal and modulate the first signal to first data, a second modulator configured to receive a second signal and modulate the second signal to second data, a path aligner configured to detect starting points of the first data and the second data and generate a control signal for synchronizing the first data and the second data, and an equalizer/decoder configured to synchronize the first and second data and to generate a signal to noise ratio and an equalizer output by a recursive equalization operation for the diversity signals thus synchronized.

Abstract: A symbol sequence corresponding to a vestigial sideband (VSB) signal is divided into a plurality of sections, respective ones of which correspond to respective time periods. Individual ones of the sections are recursively adaptively equalized to produce respective equalized sections. A bit stream is constructed from the equalized sections.

Abstract: Provided is a receiver for processing VSB signal. The receiver includes a first equalizer/decoder unit and a second equalizer/decoder unit. The first equalizer/decoder unit performs a first equalizing operation, first TCM decoding and first RS decoding on a received symbol to output a first dibit. The second equalizer/decoder unit performs a second equalizing operation, second TCM decoding and second RS decoding on the received symbol to output a transport stream. The first dibit is provided as a priori information for a soft-decision operation of the second TCM decoding.

Abstract: An OFDM (orthogonal frequency-division multiplexing) receiver circuit can include a GI (Guard Interval) combiner circuit that is configured to adaptively combine data in the GI of an OFDM formatted signal with data included in a predetermined section of an active OFDM symbol.

Abstract: An OFDM (orthogonal frequency division multiplexing) receiver is equalized by dividing each of a plurality of received OFDM symbols into a plurality of sub-symbols and outputting each of Fourier-converted signals corresponding to each of the sub-symbols, and estimating a channel response corresponding to each of the divided sub-symbols.

Abstract: Disclosed is an acoustic communication method that includes filtering an audio signal to attenuate a high frequency section of the audio signal; generating a residual signal which corresponds to a difference between the audio signal and the filtered signal; generating a psychoacoustic mask for the audio signal based on a predetermined psychoacoustic model; generating a psychoacoustic spectrum mask by combining the residual signal with the psychoacoustic mask; generating an acoustic communication signal by modulating digital data according to the acoustic signal spectrum mask; and combining the acoustic communication signal with the filtered signal.

Abstract: A method for transmitting, by a mobile device, a data object, is provided, and includes estimating expected transmission times required for transmitting an object between devices by an acoustic communication link and supported radio interfaces, based on a size of the object, transmitting the object through an acoustic communication channel when the link is estimated to provide a shortest expected transmission time, and determining rankings of the radio interfaces according to the expected transmission times when the acoustic communication link does not provide a shortest expected transmission time, transmitting rankings information and configuration information on the supported radio interfaces through the acoustic communication channel by a configuration container, and transmitting the object through a radio interface through which a response is received.

Abstract: A method for encoding an information object in a communication system by storing the information object in a buffer; generating a sampling set including bits randomly selected from the buffer and bits regularly selected from the buffer; generating control channel data including a sampling set number of the sampling set and size information for the information object; and modulating the sampling set and the control channel data.

Abstract: An orthogonal frequency division multiplexing (OFDM) equalizer includes a memory that stores OFDM frame information, a partial sum calculator configured to calculate a partial sum of a data cell corresponding to an OFDM reception signal based on a current pilot cell and a fixing coefficient corresponding to the current pilot cell, an adapting coefficient calculator configured to calculate a channel response of the data cell and calculate an adapting coefficient based on the calculated channel response and an interpolated channel response, an interpolated channel response calculator configured to calculate the interpolated channel response based on the partial sum and the adapting coefficient, and a channel compensation unit configured to output a corrected OFDM reception signal based on the fast Fourier transformed OFDM reception signal and the interpolated channel response. Related receivers and channel equalization methods are also disclosed.

Abstract: An encoder includes a precoder for encoding an input information object according to a preset encoding scheme and storing the encoded information object in a precoder buffer, a sample number/address generation unit for generating a sample number of each sample and an address, which corresponds to each bit of each sample and the address of the precoder buffer, a multiplexer for selecting a bit of the precoder buffer corresponding to the address generated by the sample number/address generation module, a sampling buffer for storing a bit of each sample output from the multiplexer, a control packet generation module for generating a control packet including information on the sample number generated by the sample number/address generation module, a packet assembling unit for assembling the sample stored in the sampling buffer with the control packet generated by the control data generation module, and a modulation module for modulating the packet output from the packet assembling unit into a sound signal accordi