Abstract: Embodiments of the present disclosure relate to device, method, device and computer readable storage media of beam-forming scheme in higher rank transmission for massive multiple input multiple output system. The method comprises determining a target beam for carrying a transmission of a reference signal from the base station to the user equipment; determining a target arrangement of the plurality of ports formed at an antenna array of the base station; and transmitting, to the user equipment, different portions of the target beam through a plurality of ports based on the target arrangement. In this way, a new beamforming method when Massive-MIMO choose higher rank transmission in multi ports communication system is proposed. The gNB would only select the best beam with different halves in the same polarization to keep the QCL principles.

Abstract: Embodiments of the present disclosure relate to device, method, device and computer readable storage media of beam-forming scheme in higher rank transmission for massive multiple input multiple output system. The method comprises determining a target beam for carrying a transmission of a reference signal from the base station to the user equipment; determining a target arrangement of the plurality of ports formed at an antenna array of the base station; and transmitting, to the user equipment, different portions of the target beam through a plurality of ports based on the target arrangement. In this way, a new beamforming method when Massive-MIMO choose higher rank transmission in multi ports communication system is proposed. The gNB would only select the best beam with different halves in the same polarization to keep the QCL principles.

Abstract: The present invention provides a data transmitting method with hybrid automatic repeat request in multi-carrier system. In this method, the signal-to-noise ratios of respective sub-carriers are compared with a threshold, the data on the sub-carriers having the signal-to-noise ratios lower than the threshold are selectively retransmitted by mapping these data onto the sub-carriers having the good channel conditions, and then the retransmitted data are combined hybrid-automatically in the receiver of the opposite terminal. By using the method the system throughput can be enhanced effectively without impairing the bit error rate of the system.

Abstract: The present invention provides a HARQ (Hybrid Automatic Repeat Request) combining method in an OFDM (Orthogonal Frequency Division Multiplexing) system, which adopts improved Chase combining method weighted by SNR and variance of SNR to realize HARQ combining. The method can improve system performance in processing power and time delay, particularly in low SNR environment, and will not make the system more complex.

Abstract: The present invention discloses a method and device for adaptive modulation and coding based on second order statistics of channel information in OFDM system, characterized in that, by means of variance of Signal-to-Noise ratio (SNR) an appropriate adaptation time window is selected dynamically to trace time-varying channel better; and in that a decision criterion of second order, namely selecting an appropriate modulation and coding schemes (MCS) according to average value of SNR and variance of SNR, is employed to obtain accurate mapping from SNR to MCS. The mapping enhances practicability of the adaptive modulation and coding, decreases probability of system outage, and thus results in better performance of bit error rate.

Abstract: The present invention provides a data transmitting method with hybrid automatic repeat request in multi-carrier system. In this method, the signal-to-noise ratios of respective sub-carriers are compared with a threshold, the data on the sub-carriers having the signal-to-noise ratios lower than the threshold are selectively retransmitted by mapping these data onto the sub-carriers having the good channel conditions, and then the retransmitted data are combined hybrid-automatically in the receiver of the opposite terminal. By using the method the system throughput can be enhanced effectively without impairing the bit error rate of the system.

Abstract: The present invention provides a HARQ (Hybrid Automatic Repeat Request) combining method in an OFDM (Orthogonal Frequency Division Multiplexing) system, which adopts improved Chase combining method weighted by SNR and variance of SNR to realize HARQ combining. The method can improve system performance in processing power and time delay, particularly in low SNR environment, and will not make the system more complex.

Abstract: The present invention discloses a method and device for adaptive modulation and coding based on second order statistics of channel information in OFDM system, characterized in that, by means of variance of Signal-to-Noise ratio (SNR) an appropriate adaptation time window is selected dynamically to trace time-varying channel better; and in that a decision criterion of second order, namely selecting an appropriate modulation and coding schemes (MCS) according to average value of SNR and variance of SNR, is employed to obtain accurate mapping from SNR to MCS. The mapping enhances practicability of the adaptive modulation and coding, decreases probability of system outage, and thus results in better performance of bit error rate.

Abstract: A method, as well as the transmitter and receiver to implement it, for carrier frequency synchronization in digital communication system, comprising the following steps and corresponding devices: at the transmitter, inserting a special PN sequence every a segment of communication signals digitally modulated and then transmitting them; wherein special PN sequences are C=R(v{circle over (x)}u); at the receiver the down-converted base band signals which contain special PN sequences are match filtered to output P complex signals containing frequency offset; transforming the P complex signals into frequency domain by FFT with likelihood function to find coarse point &OHgr;0 with maximum amplitude; searching spectrum in the small range of &OHgr;0−1 to &OHgr;0+1 with more accuracy by Chirp-Z transform to obtain point increment information &OHgr;1; finding the point increment {circumflex over (&OHgr;)} of the accurate point with maximum amplitude by quadratic interpolation on &OHgr;1; calculating fr