A wireless device receives a radio resource control message comprising an aperiodic sounding reference signal (SRS) subframe parameter. A downlink control information is received. The downlink control information indicates uplink resources in a plurality of scheduled consecutive subframes for transmission of transport blocks by the wireless device and triggers an SRS transmission in a subframe of the plurality of scheduled consecutive subframes. The SRS is transmitted in the subframe. A position of the subframe in the plurality of scheduled consecutive subframes is determined based on the aperiodic SRS subframe parameter.

A method of communication includes duplication of a first field of a first content channel into a third field in a third content channel and applying a modulation and coding scheme (MCS) to only one of the first field and the third field. The first content channel is a first portion of a frame and the third content channel is a third portion of the frame. Duplication of a second field of a second content channel into a fourth field in a fourth content channel and applying a modulation and coding scheme (MCS) to only one of the second field and the fourth field. The second content channel is a second portion of a frame and the fourth content channel is a fourth portion of the frame. The first content channel and the second content channel form a first group of content channels and the third content channel and the fourth content channel form a second group of content channels. The method then transmits the frame.

A method is used for frequency offset estimation in a wireless communication network that employs time based scheduling of packets. The method is performed by a packet receiver in the wireless communication network. The method includes receiving a packet from a packet transmitter. The packet includes a preamble that is composed of samples of a single orthogonal frequency-division multiplexing symbol. The preamble has a cyclic prefix (CP) defined by a repetition of samples from an end-portion of the preamble and the preamble, except for the CP, is free from any repeated sequence of samples. The method also includes determining a sequence of similarity measure values between the CP of the preamble and the end-portion of the preamble, applying a low-pass filter to the sequence of similarity measure values, resulting in a filtered sequence of similarity measure values, and performing frequency offset estimation on the filtered sequence of similarity measure values.

A system and method for recovering encoded data from a modulated baseband signal is disclosed. Aspects and embodiments of the system and method include receiving an analog input signal representing a modulated baseband signal, counting clock cycles of a reference clock, detecting a first transition and a second transition of the analog input signal indicating a first change and a second change in the modulated baseband signal, storing a first counter value corresponding to an amount of clock cycles elapsed between the first transition and the second transition, and determining a binary-valued bit sequence corresponding to the first counter value.

A method and a device for receiving transmitting data in in a wireless local area network are provided. The device receives a physical layer protocol data unit (PPDU) from a station over a transmission bandwidth and determines whether the station is a member of a basic service set (BSS) managed by the device based on the PPDU. When the PPDU is a multi-user (MU)-PPDU, the AP determines that the station is not a member of the BSS managed by the AP. Such MU-PPDU includes a first signal field and a second signal field, the first signal field having bandwidth information indicating the transmission bandwidth, the second signal field having user-specific information with allocation for orthogonal frequency division multiple access (OFDMA) transmission.

An audio data transmission method includes encapsulating, based on a physical layer frame header, a protocol data unit (PDU) including audio data, to obtain an audio data packet, where the physical layer frame header is modulated using a first digital modulation scheme, the PDU is modulated using a second digital modulation scheme, a value of a modulation rate of the first digital modulation scheme is equal to a value of a data transmission rate, and a value of a modulation rate of the second digital modulation scheme is less than the value of the data transmission rate, and sending the audio data packet on a BLUETOOTH low energy (BLE) physical channel at the data transmission rate.

Methods for simultaneous packet transmission (SPT) may be used to transmit packets simultaneously on a communications link such the orthogonal frequency division multiplexed multiple access (OFDMA) downlink used in used in WiFi and LTE cellular/wireless mobile data applications. A first SPT method may employ multiple data streams and selects a subset of streams to form symbols during every intervals. This allows the use of variable code rates on different streams thereby increasing the overall throughput. A second SPT method may transmit a second data stream implicitly while transmitting a data stream explicitly on a communication channel. These SPT methods may be used either individually or jointly, and may be implemented via software changes at the transmitter and the receiver. Additionally, methods for applying constrained interleaved coded modulation (CICM) to low-density parity check (LDPC) codes and decoding LDPC codes with CICM are presented.

A coding and modulation apparatus and method are presented. The apparatus comprises an encoder that encodes input data into cell words, and a modulator that modulates said cell words into constellation values of a non-uniform constellation. The modulator is configured to use, based on the total number M of constellation points of the constellation and the code rate, a non-uniform constellation from one or several groups of constellations each comprising one or more constellations.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may communicate with a base station by initiating a random access procedure with a two-root preamble. The UE may receive, from the base station, control signaling that indicates a set of root preamble sequences. The UE may transmit, to the base station, a preamble signal that is generated based on a first root preamble sequence and a second root preamble sequence of the set of root preamble sequences. The UE may then monitor for a preamble response based on the preamble signal. In some cases, the base station may be a base station in a terrestrial network. In other cases, the base station may be a satellite in a non-terrestrial network (NTN).

Provided is a radio communication system including a radio transmission apparatus including a plurality of transmission antennas and a radio reception apparatus including a plurality of reception antennas. The radio transmission apparatus includes a communication distance measurement unit configured to measure a distance between the plurality of transmission antennas and the plurality of reception antennas, a selection unit configured to select a modulation scheme common to all frequency channels indicating an orthogonality between the plurality of transmission antennas and the plurality of reception antennas, the modulation scheme satisfying an average value of index values for each of the frequency channels according to the distance between the plurality of transmission antennas and the plurality of reception antennas and satisfying a predetermined desired bit error rate, a transmission signal generation unit configured to separate transmission data into the number of all the frequency channels, modulate each item of the separated transmission data by the selected common modulation scheme, and output the transmission signals multiplexed by the number of multiplexing indicating the number of the plurality of transmission antennas to be used, and a radio signal transmitting unit. The radio reception apparatus includes a demodulation unit configured to demodulate a reception signal received by each of the plurality of reception antennas by a demodulation scheme corresponding to the modulation scheme to generate reception data.