Abstract: A wireless communication method such as a method for supporting a Device to Device (D2D) communication performed in a wireless communication system includes: receiving first and second control signals from first and second user terminals through first and second control channels, respectively; estimating an interference in a first data channel, corresponding to the first control signal or the first control channel, based on the first and the second control signals; receiving a first data signal from the first user terminal through the first data channel; and processing the received first data signal based on a result of the estimation.

Abstract: A wireless communication method such as a method for supporting a Device to Device (D2D) communication performed in a wireless communication system includes: receiving first and second control signals from first and second user terminals through first and second control channels, respectively; estimating an interference in a first data channel, corresponding to the first control signal or the first control channel, based on the first and the second control signals; receiving a first data signal from the first user terminal through the first data channel; and processing the received first data signal based on a result of the estimation.

Abstract: A method for converting a sample rate in a Software Defined Radio (SDR) communication system is provided. The method includes setting a sampling frequency range depending on a maximum sampling frequency and a minimum sampling frequency so as to enable support of a plurality of sample rates; if a required sampling frequency is set, determining a control value for converting the maximum sampling frequency to the required sampling frequency; and receiving a signal having the maximum sampling frequency, and converting the signal having the maximum sampling frequency to a signal having the required sampling frequency depending on the control value. The control value is determined taking into account a maximum sampling frequency for setting the sampling frequency range.

Abstract: A majority voting Viterbi decoder includes a branch metric calculator (BMC) for measuring a difference between a received symbol and a reference symbol and outputting branch metrics from the difference; an add-compare-selection (ACS) unit for determining an optimal path using the branch metrics; a survival path memory unit for outputting decoded symbols by performing decoding based on the optimal path; and a majority voting unit for determining a final decoded symbol by performing majority voting for the decoded symbols output from the survival path memory unit. Accordingly, by adding the majority voting unit, a decoding depth can be reduced without the loss of an encoding gain required in a system, and by reducing the decoding depth, miniaturization is possible, power consumption can be reduced, and a processing delay in a memory can be minimized.

Abstract: Disclosed are a method of and a system for controlling frame synchronization for European Digital Audio Broadcast (DAB), the method including the steps of generating a frame synchronization start-signal with respect to an incoming signal which is input when power is supplied, keeping symbol count values with the value “0” after the frame synchronization start-signal is input, transmitting a frame offset value with respect to the incoming signal, and restarting symbol counting for frame synchronization depending on the frame offset value after the frame offset value is input, wherein the frame synchronization unit may preferably transmit the frame offset value after estimating the frame offset value. In accordance with the method and system described herein, it is possible to achieve frame synchronization in short time, thereby reducing a startup time of a DAB receiver and power consumption which is needed for the frame synchronization.

Abstract: Disclosed is a demodulation circuit for demodulating an IF signal which is input via an antennal and then over-sampled at a sampling rate four times a frequency of a baseband signal, the demodulation circuit including a mixer for converting the IF signal down to a baseband signal using a coefficient corresponding to either sine values or cosine values, a DEMUX for dividing the down-converted baseband signal into a plurality of signals, and a PPF having a plurality of sub-filters for filtering the divided signals input from the DEMUX and a plurality of adders for operating the output signals of the sub-filters. As a result, the demodulation circuit can be realized in a small hardware size and is capable of reducing power consumption.

Abstract: An OFDM signal receiving apparatus and method compensates for a sampling frequency offset. Such an apparatus includes an offset estimating unit for estimating an offset for a sampling frequency that is applied to an FFT of an OFDM signal in a tracking mode, a channel estimating unit for estimating a channel delay profile using a CIR, and an offset compensating unit for compensating for an influence due to the offset by using the duration of the FFT interval transition due to the estimated offset, profile duration of the estimated channel delay profile and duration of a guard interval included in an OFDM symbol to determine a location of the channel delay profile on the guard interval. Accordingly, it is possible to compensate for a sampling frequency offset even if using a general oscillator and not a VCXO, which results in lowering cost and power consumption.

Abstract: A method and apparatus for detecting a transmit signal in a receiver in a multiple-input multiple-output (MIMO) system are provided. The method includes: dividing a constellation space into a plurality of sub-spaces, the constellation space being determined by a channel matrix, which indicates channel characteristics of the MIMO communication system, and the number of antennas; and detecting the transmit signal by calculating a metric of at least one of the sub-spaces. The apparatus includes: a channel estimation unit which estimates channel characteristics of the MIMO communication system; a preprocessing unit which preprocesses the estimated channel-characteristic data; and a signal detection unit which processes a received signal measured by the receiver using the preprocessed channel-characteristic data, divides a constellation space used to detect the transmit signal into sub-spaces, and executes a statistical algorithm on at least one of the sub-spaces.

Abstract: A method for converting a sample rate in a Software Defined Radio (SDR) communication system is provided. The method includes setting a sampling frequency range depending on a maximum sampling frequency and a minimum sampling frequency so as to enable support of a plurality of sample rates; if a required sampling frequency is set, determining a control value for converting the maximum sampling frequency to the required sampling frequency; and receiving a signal having the maximum sampling frequency, and converting the signal having the maximum sampling frequency to a signal having the required sampling frequency depending on the control value. The control value is determined taking into account a maximum sampling frequency for setting the sampling frequency range.

Abstract: A majority voting Viterbi decoder includes a branch metric calculator (BMC) for measuring a difference between a received symbol and a reference symbol and outputting branch metrics from the difference; an add-compare-selection (ACS) unit for determining an optimal path using the branch metrics; a survival path memory unit for outputting decoded symbols by performing decoding based on the optimal path; and a majority voting unit for determining a final decoded symbol by performing majority voting for the decoded symbols output from the survival path memory unit. Accordingly, by adding the majority voting unit, a decoding depth can be reduced without the loss of an encoding gain required in a system, and by reducing the decoding depth, miniaturization is possible, power consumption can be reduced, and a processing delay in a memory can be minimized.

Abstract: Disclosed is a demodulation circuit for demodulating an IF signal which is input via an antennal and then over-sampled at a sampling rate four times a frequency of a baseband signal, the demodulation circuit including a mixer for converting the IF signal down to a baseband signal using a coefficient corresponding to either sine values or cosine values, a DEMUX for dividing the down-converted baseband signal into a plurality of signals, and a PPF having a plurality of sub-filters for filtering the divided signals input from the DEMUX and a plurality of adders for operating the output signals of the sub-filters. As a result, the demodulation circuit can be realized in a small hardware size and is capable of reducing power consumption.

Abstract: Disclosed are a method of and a system for controlling frame synchronization for European Digital Audio Broadcast (DAB), the method including the steps of generating a frame synchronization start-signal with respect to an incoming signal which is input when power is supplied, keeping symbol count values with the value “0” after the frame synchronization start-signal is input, transmitting a frame offset value with respect to the incoming signal, and restarting symbol counting for frame synchronization depending on the frame offset value after the frame offset value is input, wherein the frame synchronization unit may preferably transmit the frame offset value after estimating the frame offset value. In accordance with the method and system described herein, it is possible to achieve frame synchronization in short time, thereby reducing a startup time of a DAB receiver and power consumption which is needed for the frame synchronization.

Abstract: An OFDM signal receiving apparatus and method compensates for a sampling frequency offset. Such an apparatus includes an offset estimating unit for estimating an offset for a sampling frequency that is applied to an FFT of an OFDM signal in a tracking mode, a channel estimating unit for estimating a channel delay profile using a CIR, and an offset compensating unit for compensating for an influence due to the offset by using the duration of the FFT interval transition due to the estimated offset, profile duration of the estimated channel delay profile and duration of a guard interval included in an OFDM symbol to determine a location of the channel delay profile on the guard interval. Accordingly, it is possible to compensate for a sampling frequency offset even if using a general oscillator and not a VCXO, which results in lowering cost and power consumption.