A communication system includes a repetitive orthogonal frequency-division multiplexing (“ROFDM”)transmitter communicating with an ROFDM receiver. The ROFDM transmitter includes an ROFDM modulator, which includes a K-point Fast Fourier Transform receiving a block of time-domain data symbols and generating an initial orthogonal frequency-division multiplexing symbol. The initial orthogonal frequency-division multiplexing symbol is based on a block of frequency-domain data symbols corresponding to the block of time-domain data symbols. The initial orthogonal frequency-division multiplexing symbol includes an ending part. The ROFDM modulator includes an orthogonal frequency-division multiplexing symbol repeater generating a repetitive orthogonal frequency-division multiplexing symbol by repeatedly reproducing the initial orthogonal frequency-division multiplexing symbol. The modulator includes a cyclic prefix adder pretending a cyclic prefix to the repetitive orthogonal frequency-division multiplexing symbol to generate a baseband transmitted signal. The cyclic prefix includes the ending part of the initial orthogonal frequency-division multiplexing symbol. The ROFDM receiver includes an ROFDM demodulator.

A radio-frequency (RF) sampling transmitter (e.g., of the type that may be used in 5G wireless base stations) includes a complex baseband digital-to-analog converter (DAC) response compensator that operates on a complex baseband signal at a sampling rate lower than the sampling rate of an RF sampling DAC in the RF sampling transmitter. The DAC response compensator flattens the sample-and-hold response of the RF sampling DAC only in the passband of interest, addressing the problem of a sinc response introduced by the sample-and-hold operation of the RF sampling DAC and avoiding the architectural complexity and high power consumption of an inverse sinc filter that operates on the signal at a point in the signal chain after it has already been up-converted to an RF passband.

A transmission filter includes a transmission filter circuit and an additional circuit. The transmission filter circuit defines a first signal path connecting a first terminal and a second terminal. The additional circuit is connected to a first node located between the first terminal and the transmission filter circuit on the first signal path and a second node located between the second terminal and the transmission filter circuit on the first signal path and defines a second signal path connecting the first node and the second node. The additional circuit includes, on the second signal path, a resonator group, a capacitive element, and an inductance element. The inductance element is electromagnetically coupled to the transmission filter circuit.

When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

When a plurality of terminals share the same resources in a wireless communication system, and when control information such as acknowledgement/negative acknowledgement (ACK/NAK) information or scheduling information is transmitted, a method of efficiently performing code division multiplexing (CDM) is required to distinguish the plurality of terminals. In particular, it is necessary to develop a method by which a code sequence of CDM can be selected and used according to each cell condition. Provided is a method of forming a signal in a wireless communication system in which a plurality of terminals commonly share frequency and time resources. The method includes the operations of receiving condition information in a cell; selecting one of a plurality of time domain orthogonal sequences having different lengths, according to the condition information; and allocating the selected time domain orthogonal sequence to a control signal symbol block.

Channel state information (CSI) operations are disclosed with regard to elevation beamforming (EB)/full dimension (FD) multiple input, multiple output (ED/FD-MIMO) operations. With CSI processing associated with multiple CSI-reference signal (CSI-RS) resources, ambiguities may arise in determining the CSI reporting type and rank. CSI reporting type may be determined using a last reported beam selection indicator (BI) or, in the absence of a BI, may be determined according to a predefined rule. When rank and BI are reported separately and rank is absent, user equipment may determine a default reference rank for CSI reporting based on either or both of previously reported rank or BI. When rank and BI are jointly reported, encoding schemes with fixed bitwidths determined based on either CSI-RS processes or resources may be used to enhance decoding. CSI-RS antenna ports, processes, or resources may also be used in determining application of CSI processing relaxation.

A signal sending method, a signal receiving method, and a device. The signal sending method includes: generating synchronization signals, where the synchronization signals include a first synchronization signal and a second synchronization signal; and sending the synchronization signals, where the first synchronization signal and the second synchronization signal overlap in time domain, and within a time domain resource in which the first synchronization signal and the second synchronization signal overlap, there is an intersection set between a frequency domain resource corresponding to the first synchronization signal and a frequency domain resource corresponding to the second synchronization signal. In this way, frequency domain resources occupied by the synchronization signals may be reduced, thereby saving frequency domain resources for another data transmission process. In addition, the two synchronization signals may further share a part of the frequency domain resources, thereby improving resource utilization.

A method and system analog beamforming for a single-connected antenna array is herein disclosed. A method includes estimating analog channels on a per-antenna basis, calculating explicitly an analog beamforming matrix based on the estimated analog channels, and performing analog beamforming based on the calculated analog beamforming matrix.

A sequence distributing and sequence processing method and apparatus in a communication system are provided. The sequence distributing method includes the following steps: generating sequence groups including a number of sequences, the sequences in the sequence groups are determined according to the sequence time frequency resource occupation manner which is supported by the system; distributing the sequence groups to cells. The method avoids the phenomenon that signaling transmission is needed to distribute the sequences to the cells for different time frequency resource occupation manner, and saves in so far as possible the wireless network transmission resource occupied during the process of distributing the sequences through distributing the sequence groups comprising a number of sequences to the cells.

A sequence distributing and sequence processing method and apparatus in a communication system are provided. The sequence distributing method includes the following steps: generating sequence groups including a number of sequences, the sequences in the sequence groups are determined according to the sequence time frequency resource occupation manner which is supported by the system; distributing the sequence groups to cells. The method avoids the phenomenon that signaling transmission is needed to distribute the sequences to the cells for different time frequency resource occupation manner, and saves in so far as possible the wireless network transmission resource occupied during the process of distributing the sequences through distributing the sequence groups comprising a number of sequences to the cells.