A symbol phase difference compensating portion (6) calculates a first phase difference which is a phase difference between a known pattern extracted from a received signal and a true value of the known pattern and performs phase compensation for the received signal based on the first phase difference. A tentative determination portion (12) tentatively determines an output signal of the symbol phase difference compensating portion (6) to acquire an estimated value of a phase. A first phase difference acquiring portion (13) acquires a second phase difference which is a phase difference between a phase of the output signal and the estimated value of the phase acquired by the tentative determination portion (12). A first phase difference compensating portion (14) performs phase compensation for the output signal based on the second phase difference.

A frequency estimation apparatus and method for a single receiver. The frequency estimation apparatus for the single receiver includes: a coarse frequency estimation unit estimating a coarse frequency by calculating an average of frequency estimation values for each single pulse; a direct current domain transformation unit transforming a reception signal into a direct current domain based on the coarse frequency; a fine frequency estimation unit estimating a fine frequency by applying regression analysis to a pulse train in the direct current domain of the coarse frequency; and an extremely fine frequency estimation unit estimating an extremely fine frequency by compensating an error of the coarse frequency with the fine frequency.

A digital radio receiver (7) is arranged to receive and process data frames, each data frame comprising (i) a plurality of identical synchronization sequences; (ii) identification data different from the synchronization sequences; and (iii) convolution-encoded message data. An initial-synchronization section of the receiver (7) uses the plurality of synchronization sequences in a received data frame to perform a frequency-synchronization or symbol-timing-synchronization operation. A frame-synchronization section determines frame-synchronization information by correlating at least a part of the received identification data against reference identification data stored in a memory. A convolution-decoding section uses the frame-synchronization information to decode the message data.

A transmission apparatus maps a first stream of input data to first complex symbols in serial format and convert them into first complex symbols in parallel format. They are inverse Fourier transformed into OFDM signals associated with multiple subcarriers that are transmitted via a first antenna over the multiple subcarriers in a same frequency band over a same time period that includes a same set of time slots. First pilot information is transmitted via a first antenna on a first one of a plurality of pilot subcarriers during the same set of time slots, and second pilot information is sent via a first antenna on a second one of a plurality of pilot subcarriers during the same set of time slots. The second pilot information is different from the first pilot information. A second stream of input data is similarly transformed to form second OFDM signals transmit via a second antenna over the multiple subcarriers in the same frequency band over the same time period that includes the same set of time slots. The first pilot information is transmitted via the second antenna on the second pilot subcarrier during the set of same time slots, and the second pilot information is transmitted on one of the pilot subcarriers during the same set of time slots.

Provided are a method and a device for generating a MIMO test signal which is configured to test a performance of MIMO wireless terminal. With the method, the plurality of space propagation matrixes of the MIMO testing system are acquired by performing the phase shift transformation on the plurality of calibration matrixes of the MIMO testing system, the target space propagation matrix having the isolation degree meeting the preset condition is determined according to the maximum amplitude value of elements in each inverse matrix of the plurality of space propagation matrixes, and the transmitting signal for test is generated by a calculation according to the throughput testing signal acquired by the pre-calculation and the target calibration matrix corresponding to the target space propagation matrix.

A transmission apparatus maps a first stream of input data to first complex symbols in serial format and convert them into first complex symbols in parallel format. They are inverse Fourier transformed into OFDM signals associated with multiple subcarriers that are transmitted via a first antenna over the multiple subcarriers in a same frequency band over a same time period that includes a same set of time slots. First pilot information is transmitted via a first antenna on a first one of a plurality of pilot subcarriers during the same set of time slots, and second pilot information is sent via a first antenna on a second one of a plurality of pilot subcarriers during the same set of time slots. The second pilot information is different from the first pilot information. A second stream of input data is similarly transformed to form second OFDM signals transmit via a second antenna over the multiple subcarriers in the same frequency band over the same time period that includes the same set of time slots. The first pilot information is transmitted via the second antenna on the second pilot subcarrier during the set of same time slots, and the second pilot information is transmitted on one of the pilot subcarriers during the same set of time slots.

A phase locked loop circuit that is capable of stabilizing a frequency of an input signal even in the case where the frequency is unstable is provided. The phase locked loop circuit that corrects a frequency error of an output signal from an oscillator to a predetermined target frequency; an ADC that converts the output signal to a digital signal; reference frequency output means that outputs a reference frequency signal; frequency error detection means that detects the frequency error based on the digital signal and the reference frequency signal; correction signal generation means that generates an error correction signal based on the frequency error; a DAC that converts the error correction signal to an analog signal; and a multiplier that multiplies the output signal by the analog signal to correct the frequency error of the output signal.

A frequency estimation apparatus and method for a single receiver. The frequency estimation apparatus for the single receiver includes: a coarse frequency estimation unit estimating a coarse frequency by calculating an average of frequency estimation values for each single pulse; a direct current domain transformation unit transforming a reception signal into a direct current domain based on the coarse frequency; a fine frequency estimation unit estimating a fine frequency by applying regression analysis to a pulse train in the direct current domain of the coarse frequency; and an extremely fine frequency estimation unit estimating an extremely fine frequency by compensating an error of the coarse frequency with the fine frequency.

A communication device of the disclosure includes a phase synchronizer, a first modulator, and a detector. The phase synchronizer generates a second signal on a basis of a first signal received from a communication partner. The first modulator is able to modulate the first signal on a basis of the second signal. The detector detects that synchronization between the first signal and the second signal is lost.

The multi-channel signal processing device includes a multi-channel continuous waveform (CW) phase shifter module configured to generate phase control and filter interference therein for multiple local oscillator (LO) signals at a same frequency, a multi-channel up-converter module configured to up-convert the multiple LO signals to a desired frequency and filter respective image signals therein, and a multi-channel wideband mixer module configured to receive and mix the up-converted LO signals at the desired frequency from the multi-channel up-converter module with radio frequency (RF) signals.