Aspects of the present disclosure provide techniques for uplink (UL) data channel design. An example method is provided for operations which may be performed by a first apparatus. The example method generally comprises determining a number of pilot symbols to transmit for one or more slots of a first subframe based, at least in part, on a coverage enhancement (CE) level, and transmitting at least one uplink data channel having the determined number of pilot symbols in the one or more slots of the first subframe.

Methods, systems, and devices for contention-based transmissions using differential coding techniques in mobile communication technology are described. An exemplary method for wireless communication includes transmitting, by a wireless device, a payload that comprises an identity of the wireless device and at least one of a user plane data or a control plane data, where the payload is modulated using a differential coding technique. Another exemplary method for wireless communication includes receiving, by a network node, a payload that comprises an identity of the wireless device and at least one of a user plane data or a control plane data, where the payload is modulated using a differential coding technique.

Methods, systems, and devices for wireless communications are described. A transmitting device may modulate a first binary sequence using binary phase shift keying on a first axis of a complex plane. The device may modulate a second binary sequence using binary phase shift keying on a second plane of a complex axis. The first axis and the second axis may be orthogonal. The device may transmit the first binary sequence and the second binary sequence according to the modulation of the first binary sequence and the second binary sequence.

Aspects of the present disclosure provide techniques for uplink (UL) data channel design. An example method is provided for operations which may be performed by a first apparatus. The example method generally comprises determining a number of pilot symbols to transmit for one or more slots of a first subframe based, at least in part, on a coverage enhancement (CE) level, and transmitting at least one uplink data channel having the determined number of pilot symbols in the one or more slots of the first subframe.

An apparatus for wireless communication is disclosed that performs zero-crossing-avoidance encoding for quadrature amplitude modulation. In an example aspect, the apparatus includes a polar transceiver configured to be coupled to an antenna. The polar transceiver is configured to transmit, via the antenna, data including multiple symbols associated with quadrature amplitude modulation. The multiple symbols include multiple sets of two consecutive symbols. An absolute value of a phase difference between the two consecutive symbols within each set of the multiple sets is substantially different than 180 degrees.

This disclosure describes methods, apparatus, and systems related to a modulation and coding scheme (MCS) system. The device may determine a wireless communications channel with a first device in accordance with a wireless communications standard. The device may generate a header in accordance with a communication standard, the header including, at least in part, a modulation and coding scheme (MCS) index value. The device may determine a code rate associated with the MCS index value based at least in part on the wireless communications channel. The device may cause to send the header to the first device over the wireless communications channel based at least in part on the MCS index value.

This disclosure describes methods, apparatus, and systems related to a modulation and coding scheme (MCS) system. The device may determine a wireless communications channel with a first device in accordance with a wireless communications standard. The device may generate a header in accordance with a communication standard, the header including, at least in part, a modulation and coding scheme (MCS) index value. The device may determine a code rate associated with the MCS index value based at least in part on the wireless communications channel. The device may cause to send the header to the first device over the wireless communications channel based at least in part on the MCS index value.

Aspects of the present disclosure provide techniques for uplink (UL) data channel design. An example method is provided for operations which may be performed by a first apparatus. The example method generally comprises determining a number of pilot symbols to transmit for one or more slots of a first subframe based, at least in part, on a coverage enhancement (CE) level, and transmitting at least one uplink data channel having the determined number of pilot symbols in the one or more slots of the first subframe.

This disclosure describes methods, apparatus, and systems related to a modulation and coding scheme (MCS) system. The device may determine a wireless communications channel with a first device in accordance with a wireless communications standard. The device may generate a header in accordance with a communication standard, the header including, at least in part, a modulation and coding scheme (MCS) index value. The device may determine a code rate associated with the MCS index value based at least in part on the wireless communications channel. The device may cause to send the header to the first device over the wireless communications channel based at least in part on the MCS index value.

An apparatus for wireless communication is disclosed that performs zero-crossing-avoidance encoding for quadrature amplitude modulation. In an example aspect, the apparatus includes a polar transceiver configured to be coupled to an antenna. The polar transceiver is configured to transmit, via the antenna, data including multiple symbols associated with quadrature amplitude modulation. The multiple symbols include multiple sets of two consecutive symbols. An absolute value of a phase difference between the two consecutive symbols within each set of the multiple sets is substantially different than 180 degrees.