Methods, systems, and devices for wireless communication are described. A base station may identify a first synchronization sequence and generate a second synchronization sequence based at least in part on the first synchronization sequence. The base station may map the first synchronization sequence to a first resource block of a synchronization channel associated with a first frequency sub-band of a shared radio frequency spectrum band and the second synchronization sequence to a second resource block associated with a second frequency sub-band of the synchronization channel. The base station may then transmit the first synchronization sequence and the second synchronization sequence concurrently over the synchronization channel using the first resource block and the second resource block according to the mapping. In some cases, the second synchronization sequence may be generated by applying a first phase shift to the first synchronization sequence.

Systems and methods related to scheduling for a cluster of cells controlled by a base station of a cellular communications network are disclosed. In some embodiments, a method of operation of a base station in a cellular communications network to provide scheduling for a cluster of cells controlled by the base station is provided. In some embodiments, the method of operation of the base station comprises identifying a first set of Radio Access Bearers (RABs) for cluster scheduling for a Transmit Time Interval (TTI) and a second set of RABs for individual cell scheduling for the TTI, where the first set of RABs and the second set of RABs are non-over-lapping sets. The method further includes performing cluster scheduling for the first set of RABs for the TTI and performing individual cell scheduling for the second set of RABs for the TTI.

Systems, methods, and apparatuses are described for wireless communications. A wireless device may transmit an uplink signal via a cell of a cell group. Transmission timing of the uplink signal may be based on a cell of the cell group and a timing adjustment associated with a different cell group.

User equipment associated with a legacy network may utilize a bottom-to-top search technique to identify relevant control channel samples. Generating a control channel that is configured for the bottom-to-top search technique may lead to poor performance in a single-carrier waveform, which may be disadvantageous as networks move toward New Radio. In some aspects, described herein, a base station generates a control channel that is configured to minimize gaps in the control channel, and a user equipment performs a top-to-bottom search technique to identify relevant control channel samples. By using the top-to-bottom search technique, degradation of single-carrier waveforms is reduced and efficiency is improved.

In order to provide a transmission device and transmission method with which a response signal for random access preamble transmitted from a preamble transmission device is efficiently transmitted, setting unit in base station sets a first resource candidate group, which enables terminal capable of receiving a latch response transmitted by demodulation reference signal (DMRS) transmission to be selected, and a second resource candidate group, which enables terminal incapable of receiving a latch response transmitted by DMRS transmission but capable of receiving a latch response transmitted by cell-specific reference signal (CRS) transmission to be selected. Control unit selects DMRS transmission as the latch response transmission method when a resource in which latch preamble has been received is included in the first candidate group, but selects CRS transmission as the latch response transmission method when the resource is included in the second resource candidate group.

Apparatus and methods for disrupting or preventing periodicity in DTC circuits are provided. In an example, a communication circuit can include a digital-to-time converter (DTC) and a processing path coupled to the DTC. The DTC can be configured to receive reference information, modulation information and first dither information, and to provide a modulated signal using the reference information, the modulation information and the first dither information. The processing path can be configured to receive second dither information and to cancel the first dither information using the second dither information, wherein the DTC is configured to disrupt processing periodicity of the communication circuit using the first dither information.

Disclosed is a random access method for a machine type communication (MTC) terminal. The random access method performed by a terminal includes performing a cell search, determining a radio environment based on time taken to perform the cell search, and performing different random access procedures depending on the determined radio environment. Accordingly, coverage of the MTC terminal that is in a poor radio environment may be enhanced, thereby performing normal communication with a base station.

Certain aspects of the present disclosure relate to methods and apparatus for generating synchronization signals for cell synchronization. Certain aspects of the present disclosure provide a method for wireless communication. The method generally includes determining a symbol index for transmitting a sequence; determining an amount of cyclical shift in one of a frequency domain and a time domain to apply to the sequence, wherein the amount of cyclical shift in the frequency domain is based on the sequence and the symbol index; shifting the sequence by the amount of cyclical shift; and transmitting the shifted sequence in a symbol corresponding to the symbol index.

Techniques are described for wireless communication. A first method may include performing a clear channel assessment (CCA) on an unlicensed radio frequency spectrum band; transmitting an indication of a time division duplexing (TDD) configuration over the unlicensed radio frequency spectrum band when the CCA is successful; and transmitting downlink data over the unlicensed radio frequency spectrum band in accordance with the TDD configuration when the CCA is successful. A second method may include performing a CCA on an unlicensed radio frequency spectrum band; dynamically determining, based at least in part on at least one grant to a user equipment (UE), and for a period following the CCA, a number of uplink subframes for communication over the unlicensed radio frequency spectrum band; and transmitting downlink data over the unlicensed radio frequency spectrum band in accordance with the timing of the number of uplink subframes when the CCA is successful.

Systems and methods for transmitting data using various Modulation on Zeros schemes are described. In many embodiments, a communication system is utilized that includes a transmitter having a modulator that modulates a plurality of information bits to encode the bits in the zeros of the z-transform of a discrete-time baseband signal. In addition, the communication system includes a receiver having a decoder configured to decode a plurality of bits of information from the samples of a received signal by: determining a plurality of zeros of a z-transform of a received discrete-time baseband signal based upon samples from a received continuous-time signal, identifying zeros that encode the plurality of information bits, and outputting a plurality of decoded information bits based upon the identified zeros.