A receiving device performs, in an equalization processing circuit that performs an equalizing process for a received signal sequence and outputs a sequence to be demodulated, a first transmission-path estimating process of generating a first compensation coefficient indicating a propagation coefficient of a transmission path of a received signal, based on a preamble sequence, a second transmission-path estimating process of generating a second compensation coefficient from a received header-replica sequence generated by performing demodulation and modulation for a header sequence included in a first equalizer-compensated output sequence in which distortion has been compensated based on the first compensation coefficient, a third transmission-path estimating process of generating a third compensation coefficient by synthesizing the first and second compensation coefficients with each other, and a propagation-path compensating process of performing a distortion compensating process for a payload sequence included in the received signal sequence based on the third compensation coefficient.

A method for channel estimation, performed by a wireless transmit/receive unit (WTRU), includes: receiving a plurality of input signals, generating a plurality of sensing matrices for the input signals, generating an augmented sensing matrix and an augmented observation vector according to the sensing matrices and the input signals, estimating a plurality of channel delay parameters according to the augmented sensing matrix and the augmented observation vector, and estimating channel information according to the channel delay parameters.

The disclosure is directed to an OFDM receiver with a low-resolution ADC and an electronic device thereof. According to one of the exemplary embodiments, the OFDM receiver may include not limited to: an ADC module which receives a transmission signal of a channel in an analog format and digitizes the transmission signal into a digital format to generate a quantized transmission signal; an error compensating and estimating module which is coupled to the ADC module, receives the quantized transmission signal and a feedback signal which is a first estimated time-domain transmission signal to generate an estimated error signal according to a turbo iterative updating technique; and a signal estimating module which is coupled to the error compensating and estimating module, receives the estimated error signal and a channel attenuation coefficient of the channel to generate an estimated transmission signal.

This disclosure describes systems, methods, and devices related to a trigger-based null data packet (NDP) for channel sounding system. A device may send a trigger frame to a group of station devices, the group of station devices including a first station device, the trigger frame indicating a high efficiency (HE) long training field (HE-LTF) mode and a guard interval duration. The device may identify a HE trigger-based (TB) null data packet (NDP) received from the first station device, the HE TB NDP including a first packet extension field, wherein the HE TB NDP is associated with the HE-LTF mode and the guard interval duration indicated in the trigger frame. The device may send a downlink NDP including a second packet extension field, a second HE-LTF mode, and a second guard interval duration. The device may determine channel state information based on HE TB NDP received from the first station device.

Apparatuses, methods, and systems are disclosed for determining a magnitude of a composite zero-forcing equalizer. One method includes measuring a first frequency response at a first antenna connector. The method includes determining a first zero-forcing equalizer for the first antenna connector as an inverse of the first frequency response. The method includes measuring a second frequency response at a second antenna connector. The method includes determining a second zero-forcing equalizer for the second antenna connector as an inverse of the second frequency response. The method includes determining a magnitude of a composite zero-forcing equalizer as a square root of a weighted combination of squares of magnitudes of the first zero-forcing equalizer and the second zero-forcing equalizer. A first weight applied for the first antenna connector is a square of a first power measured at the first antenna connector.

A communication device that is configured to: compute reflected transmission weights based on timing correction coefficients to be applied to each of a plurality of antennas according to reception timings of uplink signals from a plurality of wireless terminals that receive multiplexed downlink signals transmitted from the plurality of antennas, and on respective channel estimation values between the plurality of antennas and the plurality of wireless terminals, the computed reflected transmission weights reflecting the timing correction coefficients and being computed at first frequency intervals; compute interpolated transmission weights by interpolating between the computed reflected transmission weights at second frequency intervals that are narrower than the first frequency intervals; and compute transmission weights to be applied to downlink signals by, based on the timing correction coefficients, correcting the interpolated transmission weights that have been interpolated such that the timing correction coefficients are reflected a second time.

A transmitting device includes: a transmission signal generation circuit that generates a transmission signal using a frame format including a legacy short training field (STF), a legacy channel estimation field (CEF), a legacy header field, an enhanced directional multi-gigabit (EDMG) header field, an EDMG-STF, an EDMG-CEF, and a data field; and a transmission circuit that transmits the generated transmission signal using one or more channels, wherein the legacy header field includes a data length field expressed by multiple bits, and the data length field indicates, to a legacy terminal, information related to a data length using all of the multiple bits, and indicates, to an EDMG terminal, information related to a data length using a subset of the multiple bits, and uses the remaining bit or bits to indicate information related to the one or more channels in which the transmission signal is transmitted.

The present invention relates to a method and apparatus for demodulation in a wireless communications system transmitted across a wireless communications channel. The described wireless receiver includes a first antenna for receiving a wireless signal including a symbol transmitted across a wireless communications channel perceived by the first antenna, an observation modifier for generating a modified observation (y) of the symbol based on a product of the received observation (r) and the complex conjugate of a channel estimate (h*), a log-likelihood ratio (LLR) module generating log-likelihood ratios (LLRs) based on the modified observation and the channel estimate, and a maximum-likelihood-based decoder for decoding the symbol based on the LLRs.

Method and apparatus of obtaining better detection performance by improving matrix condition for an MN over-determined MIMO system are disclosed. The condition of a matrix to be inverted for solving various detection problems is improved by reordering equations of the original MIMO system, resulting in a reordered channel matrix and reordered received signal vector so that the top NN sub-matrix has the largest determinant among all NN sub-matrices of the reordered channel matrix. The disclosed method may be used to obtain a more accurate estimate of the transmit data bits.

Embodiments relate to apparatuses (10; 20), methods and computer programs for determining transmission control information. The Apparatus (10) is suitable for a base band unit (110) of a base station transceiver (100) of a mobile communication system (300), the base station transceiver (100) further comprising one or more radio units (120) configured to wirelessly communicate with the base band unit (110) using one or more wireless fronthaul links. The apparatus (10) comprises at least one output (12) configured to transmit a downlink component of the one or more wireless fronthaul links to the one or more radio units (120). The apparatus (10) further comprises at least one input (14) configured to receive an uplink component of the one or more wireless fronthaul links from the one or more radio units (120). The apparatus (10) further comprises a control module (16) configured to control the at least one output (12) and the at least one input (14). The control module (16) is further configured to transmit a reference signal via the at least one output (12) to the one or more radio units (120). The control module (16) is further configured to receive a loopback version of the reference signal via the at least one input (14) from the one or more radio units (120). The control module (16) is further configured to determine transmission control information based on an attenuation of the reference signal determined based on the loopback version of the reference signal. The transmission control information comprises information related to a per-radio unit transmission power to be used by the one or more radio units (120) for transmissions on the one or more wireless fronthaul links. The control module (16) is further configured to provide the transmission control information to the one or more radio units (120) via the at least one output (12).