Method and device for configuring a waveform at a transmitter are provided. The method includes: receiving at least one input signal, each input signal corresponding to a subcarrier spacing setting; performing IDFT pre-processing to each input signal, the IDFT pre-processing including DFT pre-coding or offset modulation; performing IDFT to each input signal which is subjected to the IDFT pre-processing, the IDFT including an IDFT with parameters including resource mapping and a corresponding IDFT size; performing IDFT post-processing to each input signal which is subjected to the IDFT to obtain at least one output signal, the IDFT post-processing including cyclic extension and time-domain windowing; adding the at least one output signal in time domain; and transmitting the added signal through a corresponding antenna port. Waveforms are configured flexibly according to practical scenarios at the transmitter to determine a most suitable waveform for current scenario, which meets practical requirements of 5G technology.

According to an embodiment of the present invention, a data transmission method for a station (STA) device in a wireless LAN (WLAN) system includes the steps of: generating a physical protocol data unit (PPDU) that includes a physical preamble and a data field; and transmitting the PPDU. Therein: the whole transmission band of the PPDU is made up of a plurality of resource units in a frequency region; each of the plurality of resource units is configured from a preset number of tones; resource units, from among the plurality of resource units, that have the same logical index are allocated to the same STA; and the resource units that have the same logical index may be discontinuously located in the frequency region.

An apparatus and method for generating a broadcast signal frame for signaling a time interleaving mode are disclosed. An apparatus for generating broadcast signal frame according to an embodiment of the present invention includes a time interleaver configured to generate a time-interleaved signal by performing time interleaving on a BICM output signal; and a frame builder configured to generate a broadcast signal frame including a preamble for signaling a time interleaving mode corresponding to the time interleaver for each of physical layer pipes (PLPs).

A multi-carrier communication system such as an OFDM or DMT system has nodes which are allowed to dynamically change their receive and transmit symbol rates, and the number of carriers within their signals. Changing of the symbol rate is done by changing the clocking frequency of the nodes' iFFT and FFT processors, as well as their serializers and deserializers. The nodes have several ways of dynamically changing the number of earners used. The selection of symbol rate and number of earners can be optimized for a given channel based on explicit channel measurements, a priori knowledge of the channel, or past experience. Provision is made for accommodating legacy nodes that may have constraints in symbol rate or the number of carriers they can support. The receiver can determine the correct symbol rate and number of earners through a priori knowledge, a first exchange of packets in a base mode that all nodes can understand, or an indication in the header of the data packet which is transmitted in a base mode of operation that all nodes can understand.

An estimation device is provided. The distance estimation device includes a calibration circuit and a distance estimation circuit. The calibration circuit may receive channel state information (CSI), and obtain signal-path power and noise-path power according to the CSI, and perform calculation to divide the signal-path power by the noise-path power to obtain a signal-power calibration value. The distance estimation circuit is coupled to the calibration circuit. The distance estimation circuit receives a received signal strength indication (RSSI) and the signal-power calibration value, and obtains a path-loss exponent according to the RSSI and the signal-power calibration value, and obtains a distance-estimation value according to the signal-power calibration value and the path-loss exponent.

A discrete Fourier transform spread orthogonal time frequency space modulation method comprises the steps of performing DFT preceding processing and delay-Doppler domain mapping processing on the transmit data symbols, OTFS modulator, and performing delay-Doppler domain demapping processing and IDFT decoding processing on a received signal to realize demodulation; compared with the existing waveforms, including OFDM and DFT-s-OFDM, the proposed DFT-s-OTFS can reduce the bit error rate under high Doppler spread and the peak-to-average power ratio of the transmitted signal at the same time.

An OFDM signal transmission apparatus is provided, which includes a mapping unit configured to map first signals into N subcarriers and second signals into M subcarrier(s) to form an OFDM signal, wherein N is larger than M. The first signals are each indicating a same bit of retransmission information and the second signals are each indicating a same bit of information other than retransmission information. The OFDM signal transmission apparatus further includes a transmitting unit configured to transmit the formed OFDM signal.

An adaptable orthogonal frequency-division multiplexing system (OFDM) that uses a multiple input multiple output (MIMO) to having OFDM signals transmitted either in accordance with time diversity to reducing signal fading or in accordance with spatial diversity to increase the data rate. Sub-carriers are classified for spatial diversity transmission or for time diversity transmission based on the result of a comparison between threshold values and at least one of three criteria. The criteria includes a calculation of a smallest eigen value of a frequency channel response matrix and a smallest element of a diagonal of the matrix and a ratio of the largest and smallest eigen values of the matrix.

Embodiments of this application provide a side information transmission method and apparatus. Data to be transmitted by a transmit end includes at least one first data sub-block and at least one second data sub-block. A first modulated signal is obtained based on a first phase rotation factor. A second modulated signal is obtained based on a second phase rotation factor. Side information is generated based on the first phase rotation factor and the second phase rotation factor. The first data sub-block is carried on a first subcarrier, and the side information is also mapped to the first carrier. The first modulated signal corresponding to the at least one first data sub-block, the second modulated signal corresponding to the at least one second data sub-block, and a modulated signal corresponding to the side information are superposed to obtain a to-be-transmitted signal.

A front-end unit that operates within a C-RAN architecture to perform the functions of cellular signal processing and resource selection between an RRU and the BBU pool network is described. The front-end unit supports flexible load migration and CoMP (coordinated multipoint) in the CRAN BBU while also reducing data transmission within the BBU pool network or between the BBU pool network and the RRU.