A transmission method is provided for a communication system in which communications using a plurality of communication methods having different transmission parameters are performed at the same frequency (in frequency bands that at least partially overlap with each other). The transmission method includes: generating a first symbol group that includes a control symbol for causing a communication partner apparatus to recognize that communication using a first communication method is to be performed and a second symbol group that includes a data symbol for the first communication method; transmitting the first symbol group at a first transmit power; and transmitting the second symbol group at a second transmit power that is smaller than the first transmit power.

Joint estimation of the framer index and the frequency offset in an optical communication system are described among various other features. A transmitter can transmit data frames using pilot and framer symbols. A receiver can estimate the framer index and frequency offset using the pilot and framer symbols, and identify the beginning of a header portion of a data frame. By identifying the beginning of the header portion of a data frame, the receiver can then process data received from the transmitter in a manner synchronous to the manner in which the data was transmitted by the transmitter.

Processes and device configurations are provided for extracting observables from communications signals. Methods include performing a frequency extraction on received communication signals to determine a carrier frequency, acquiring an estimation of channel frequency response and a frame start time. Signal tracking is performed to update frame start time of a signal physical broadcast channel block structure (SS/PBCH) in the communication signal, and at least one observable is extracted from the communications signal based on the updated estimate of frame start time. Characteristics of communications signal, such as frame structure including a synchronization signal physical broadcast channel block structure (SS/PBCH) may be used to opportunistically extract time of arrival (TOA) from communications signals. Symbols and subcarriers of new radio signals may be used to extract reference signals, and to determine one or more navigation observables based on communication signal.

Embodiments disclosed herein include systems and methods for locating all synchronization signal blocks on a 5G new radio channel. Such systems and methods can include measuring downlink signal energy over a bandwidth of the 5G new radio channel to identify a center frequency of a signal broadcast on the 5G new radio channel, processing the signal at the center frequency of the signal to identify a first of a plurality of synchronization signal blocks and global OFDM symbol boundaries for the wireless radio channel, and using the global OFDM symbol boundaries for all raster frequencies of the 5G new radio channel to identify remaining ones of the plurality of synchronization signal blocks.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station (BS), information identifying a core resource set (CORESET) for one or more shared radio frequency spectrum channels. The CORESET may be configured into a plurality of resource blocks based at least in part on a resource block granularity associated with the one or more shared radio frequency spectrum channels. The UE may communicate with the BS using the CORESET. Numerous other aspects are provided.

An OFDM system uses a normal mode which has a symbol length T, a guard time TG and a set of N sub-carriers, which are orthogonal over the time T, and one or more fallback modes which have symbol lengths KT and guard times KTG where K is an integer greater than unity. The same set of N sub-carriers is used for the fallback modes as for the normal mode. Since the same set of sub-carriers is used, the overall bandwidth is substantially constant, so alias filtering does not need to be adaptive. The Fourier transform operations are the same as for the normal mode. Thus fallback modes are provided with little hardware cost. In the fallback modes the increased guard time provides better delay spread tolerance and the increased symbol length provides improved signal to noise performance, and thus increased range, at the cost of reduced data rate.

A first orthogonal frequency division multiplexing (OFDM) frame signal is generated that includes a grid of multiple frequency subcarriers and multiple time periods. An OFDM symbol is transmitted using multiple frequency subcarriers during a time period and includes known reference OFDM symbols assigned to corresponding time-frequency resource elements in the grid, Each resource element is defined by a one of the multiple frequency subcarriers and one of the multiple time periods. A second orthogonal frequency division multiplexing (OFDM) frame signal is generated that includes a grid of multiple frequency subcarriers and multiple time periods and includes known reference OFDM symbols assigned to corresponding time-frequency resource elements in the grid. The time-frequency resource elements in the grid assigned to the known reference OFDM symbols in the first OFDM frame signal are different from the time-frequency resource elements in the grid assigned to the known reference OFDM symbols in the second OFDM frame signal. The first OFDM frame signal is converted to a first radio signal and the second OFDM frame signal to a second radio signal. The first radio signal is transmitted from a first antenna and the second radio signal from a second, different antenna.

A wireless device receives control message(s) comprising parameters of a plurality of cell groups and a pathloss reference for each secondary cell. The wireless device transmits uplink signals in a first secondary cell in a secondary cell group. Transmission power of the uplink signals is determined employing a received power of the pathloss reference assigned to the first secondary cell. Timing of the uplink signals in the secondary cell group employs a synchronization signal on an active secondary cell in the secondary cell group as a timing reference.

The present technology relates to a reception apparatus, a reception method, and a program capable of improving performance in diversity. The reception apparatus includes a plurality of demodulation units configured to demodulate a supplied branch and generate a symbol and a synthesis unit configured to synthesize the symbol demodulated by the plurality of demodulation units, in which the synthesis unit sets a predetermined time from arrival time of a first-arriving symbol as a search range, and synthesizes a symbol that arrives within the search range and the first-arriving symbol. The present technology can be applied to a mobile terminal apparatus that receives television broadcasting or the like with diversity system.

The Direct Synchronization of Synthesized Clock (DSSC) contributes a method, system and apparatus for reliable and inexpensive synthesis of inherently stable local clock synchronized to a referencing signal received from an external source. Such local clock can be synchronized to a referencing frame or a data signal received from wireless or wired communication link and can be utilized for synchronizing local data transmitter or data receiver. Such DSSC can be particularly useful in OFDM systems such as LTE/WiMAX/WiFI or Powerline/ADSL/VDSL, since it can secure lower power consumption, better noise immunity and much more reliable and faster receiver tuning than those enabled by conventional solutions.