The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.

A communications system comprises a maximum ratio combining (MRC) circuit for receiving a plurality of input data streams and for processing the plurality of input data streams using maximum ration combining to improve signal to noise ratio. A MIMO transmitter transmits the MRC processed carrier signal over a plurality of separate communications links from the MIMO transmitter, each of the plurality of separate communications links from one transmitting antenna of a plurality of transmitting antennas to each of a plurality of receiving antennas at a MIMO receiver.

The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.

An Orthogonal Time Frequency Space Modulation (OTFS) modulation scheme that maps data symbols, along with optional pilot symbols, using a symplectic-like transformation such as a 2D Fourier transform and optional scrambling operation, into a complex wave aggregate and be backward compatible with legacy OFDM systems, is described. This wave aggregate may be processed for transmission by selecting portions of the aggregate according to various time and frequency intervals. The output from this process can be used to modulate transmitted waveforms according to various time intervals over a plurality of narrow-band subcarriers, often by using mutually orthogonal subcarrier “tones” or carrier frequencies. The entire wave aggregate may be transmitted over various time intervals. At the receiver, an inverse of this process can be used to both characterize the data channel and to correct the received signals for channel distortions, thus receiving a clear form of the original data symbols.

The apparatus may be a base station. The apparatus processes a plurality of synchronization signals by performing time-division multiplexing (TDM) of at least one of a plurality of first synchronization signals of different types and at least one of the plurality of second synchronization signals of different types, the plurality of synchronization signals including the plurality of first synchronization signals and the plurality of second synchronization signals. The apparatus transmits the processed synchronization signals to a user equipment (UE).

The apparatus may be a base station. The apparatus processes a first group of synchronization signals. The apparatus processes a second group of synchronization signals. The apparatus performs a first transmission by transmitting the processed first group of the synchronization signals in a first synchronization subframe. The apparatus performs a second transmission by transmitting the processed second group of the synchronization signals in a second synchronization subframe.

The apparatus may be a base station. The apparatus sets a first numerology for at least one synchronization signal of one or more synchronization signals to be different from a second numerology for at least one data signal of one or more data signals. The apparatus transmits the one or more synchronization signals to a user equipment (UE) based on the first numerology. The apparatus transmits the one or more data signals to the UE based on the second numerology.

The apparatus may be a base station. The apparatus sets a first numerology for at least one synchronization signal of one or more synchronization signals to be different from a second numerology for at least one data signal of one or more data signals. The apparatus transmits the one or more synchronization signals to a user equipment (UE) based on the first numerology. The apparatus transmits the one or more data signals to the UE based on the second numerology.

Aspects of the present disclosure provide for the transmission of various synchronization signals with variable periodicity. For synchronization signals with long periodicity, in some aspects of the disclosure, the synchronization signals may be transmitted as single-frequency-network (SFN) synchronization signals and/or the synchronization signals may be repeated a number (N) of times within a synchronization burst to reduce user equipment (UE) search latency and improve UE measurement accuracy. In some examples, the synchronization signals may be repeated within a synchronization burst using a repetition pattern that may be configurable based on the periodicity of transmission or fixed for one or more periodicities of transmission.

A method of a communication device configured with two or more multi-user coordination modes for communication with a plurality of users is disclosed. The method comprises determining an available spatial selectivity for the plurality of users, and selecting one of the two or more multi-user coordination modes based on the determined available spatial selectivity and a number of users of the plurality. Corresponding apparatus, communication receiver and computer program product are also disclosed.