Patent classifications
H04L27/2654
Receiver and FBMC reception method with low decoding latency
The invention relates to a receiver and a FBMC reception method making it possible to reduce the decoding latency time and to increase the data rate in a communication system using a handshake exchange protocol or a TDMA access protocol. The receiver introduces zero padding values in place of the last samples of the last block of samples of a FBMC packet, without waiting for the end of this packet. The decoding of the FBMC packet is thus decoded more rapidly, without significant degradation of the error rate and without reduction of the out-of-band rejection rate of the FBMC signal.
METHOD AND AUXILIARY METHOD, APPARATUS, BASE STATION AND USER EQUIPMENT FOR INTERFERENCE CANCELLATION
The present disclosure provides a method for interference cancellation which includes: calculating a mean value and a variance value of a received signal to obtain statistics information of the received signal; calculating an estimating log-likelihood ratio using the statistics information of the received signal; calculating a decoding log-likelihood ratios of the received signal using the estimating log-likelihood ratio of the received signal, and performing calculations to update the statistics information of the received signal; repeating the above steps for a pre-determined number of times, performing hard decisions on the decoding log-likelihood ratios of the received signal, and outputting data bits obtained from the hard decision. The present disclosure also provides an apparatus, an auxiliary method, a base station and a terminal device for interference cancellation. The mechanism of the present disclosure can reduce the impact of inherent interference in the FBMC/OQAM system on system performances, and increase spectral efficiency and design flexibility of the FBMC/OQAM system.
Transformation between time domain and frequency domain based on nearly orthogonal filter banks
A filter bank for signal decomposition is provided. The filter bank comprises a plurality of filter units each of which has one input and two outputs forming two paths whose transfer functions are complementary to each other, where the plurality of filter units are connected to form a tree structure.
Method and apparatus for transmitting and receiving signal using variable observation length in multicarrier system using non-orthogonal transmission signal
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method and apparatus for transmitting and receiving signals using a variable observation length in a multi-carrier system using the non-orthogonal transmission signal. A receiver performs fast Fourier transform on reception vectors contained in the signal, equalizes the fast Fourier transformed reception vectors by a 1-tap zero forcing equalizer, and applies a reception filter based on the observation length to the equalized reception vectors. A transmitter includes a transceiver configured to transmit and receive a signal, and a controller configured to cause the transceiver to transmit an indicator for a Modulation and Coding Scheme (MCS) level to a receiver based on a channel state, and transmit a signal applied with the MCS level to the receiver.
Method and apparatus for channel estimation and equalization in QAM-FBMC system
The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4th-Generation (4G) communication system such as Long Term Evolution (LTE). A method and apparatus for channel estimation and equalization in a cellular environment based on quadrature amplitude modulation-filter bank multicarrier (QAM-FBMC) transmission is provided. The signal transmission method for a transmitter includes sending channel measurement information to a receiver, receiving channel related information from the receiver, selecting a first filter and a second filter to be used for signal transmission according to the received channel related information, mapping, when no performance difference is present between the first filter and the second filter, reference symbols evenly to subcarriers associated with the first filter and subcarriers associated with the second filter, mapping, when a performance difference is present between the first filter and the second filter, reference symbols preferentially to subcarriers associated with the transmitting filter with higher performance, and sending a transmit signal having the mapped reference symbols.
Data sending method, apparatus, and device, and data receiving method, apparatus, and device
A transmit end determines M first time-frequency resource locations and S second time-frequency resource locations, and determines, in the S second time-frequency resource locations, S/2 second time-frequency resource locations as a first set, and S/2 second time-frequency resource locations excluding the second time-frequency resource locations in the first set as a second set; determines a communication data symbol sent at the second time-frequency resource locations in the first set; obtains, a compensation data symbol sent at the second time-frequency resource locations in the second set, where interference of the communication data symbol to the pilot data symbol cancels out interference of the compensation data symbol to the pilot data symbol; and separately sends the pilot data symbol at the M first time-frequency resource locations, and sends the communication data symbol and the compensation data symbol at the S second time-frequency resource locations.
Method and apparatus for repeated transmission in multicarrier wireless communication system
A method for signal transmission includes determining whether to perform repeated transmissions for a time length of a multiplication of L and M or more, wherein L indicates the overlapping factor of the system and M indicates a number of quadrature amplitude modulation (QAM) filter bank multi-carrier (FBMC) symbols, determining information on a type of the repeated transmissions to be performed, and transmitting FBMC symbols using a transmit power determined based on the type of the repeated transmissions. A base station includes a transceiver unit to send and receive signals, a control unit configured to determine whether to perform repeated transmissions for a time length of a multiplication of L and M or more, determine information on a type of the repeated transmissions to be performed, and transmit FBMC symbols using a transmit power determined based on the type of the repeated transmissions.
RESOURCE BLOCK BASED MULTICARRIER MODULATIONS FOR AGILE SPECTRUM
A resource block (RB)-based multicarrier modulation (MCM) transmitter and receiver structure for spectral agile systems are disclosed. The transmitter and the receiver are capable of sharing opportunistically available and non-contiguous channels with other users. The RB-MCM partitions the available spectrum, contiguous or non-contiguous, into multiple RBs (same or different sizes), applies a baseband MCM or single carrier modulation, or coded single carrier or multicarrier schemes in each RB with a type of spectral leakage reduction technique, and applies RB modulation for each RB to modulate the signal from baseband to the frequency band of that RB. At the receiver, the received signal may be filtered and RB demodulation may be applied to put each RB signal in baseband and a baseband multicarrier or single carrier or coded single carrier or coded multicarrier demodulation may be applied to each RB signal. Different RBs may use different modulation schemes.
VARIABLE LATENCY DATA COMMUNICATION USING ORTHOGONAL TIME FREQUENCY SPACE MODULATION
A system and method of variable latency data transmission. The method includes transforming a first original data frame in accordance with a first time-frequency transformation so as to provide a first transformed data frame wherein the first time-frequency transformation is associated with a first latency. The method further includes transforming a second original data frame in accordance with a second time-frequency transformation so as to provide a second transformed data frame wherein the second time-frequency transformation is associated with a second latency. Using a transmitter, elements of the first transformed data frame are transmitted over a first frame period corresponding to the first latency and elements of the second transformed data frame are transmitted over a second frame period corresponding to the second latency wherein the first frame period is different from the second frame period.
SYSTEM AND METHOD FOR IMPLEMENTING ORTHOGONAL TIME FREQUENCY SPACE COMMUNICATIONS USING OFDM
A system and method for orthogonal time frequency space communication and waveform generation. The method includes receiving a plurality of information symbols and encoding an NM array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency. The two-dimensional array of modulation symbols is then transmitted using M mutually orthogonal waveforms included within M frequency sub-bands.