A precoding process is performed on a first baseband signal and a second baseband signal to generate a first precoding signal and a second precoding signal. A pilot signal is inserted into the first precoding signal and phase change is performed on the second precoding signal. A pilot signal is inserted into the phase changed second precoding signal, and phase change is further performed on the phase-changed second precoding signal with the pilot signal inserted.

A transmission device that improves data reception quality includes: a first pilot inserter that inserts a pilot signal into a first precoded signal; a phase changer that applies a phase change of i×Δλ to the second precoded signal, where i is a symbol number and an integer that is greater than or equal to 0; an inserter that inserts a pilot signal into the second precoded signal applied with the phase change; and a phase changer that applies a phase change to the second precoded signal applied with the phase change and inserted with the pilot signal. Δλ satisfies n/2 radians<Δλ<π radians or π radians<Δλ<3π/2 radians. When the communications scheme is an OFDM scheme, the phase changer and the phase changer apply a phase change, and when the communications scheme is a single-carrier scheme, do not apply a phase change.

A method for signal processing includes receiving at a given location at least first and second signals transmitted respectively from at least first and second antennas (34) of a wireless transmitter (24). The at least first and second signals encode identical data using a multi-carrier encoding scheme with a predefined cyclic delay between the transmitted signals. The received first and second signals are processed, using the cyclic delay, in order to derive a measure of a phase delay between the first and second signals. Based on the measure of the phase delay, an angle of departure (θ) of the first and second signals from the wireless transmitter to the given location is estimated.

A method, a system, and a computer program product for enabling reliable millimeter links in wireless communications systems. One or more beams associated with a plurality of communication paths is trained to determine one or more angles corresponding to the beams at which the beams are received by at least one of a first communication device and a second communication device. Using the determined one or more angles, at least one communication path in the plurality of communication paths is selected for transmission of one or more data packets between the first and second communication devices. Using the selected communication path, one or more data packets are transmitted.

A wireless audio system including a transmitter using multiple antenna diversity techniques for different signal types is provided. Multipath performance may be optimized, along with improved spectral efficiency of the system.

Aspects directed towards receiving at a sidelink node from and communicating to peer sidelink nodes an indication on whether the CDD antenna diversity scheme is used in a data transmission are disclosed. Also disclosed is the receiving sidelink node optimizing its operation based on the knowledge of whether the CDD antenna diversity scheme is used in the data transmission and thus the performance at the receiving sidelink node is improved. Also disclosed are aspects directed to a peer sidelink node determining whether to use the CDD antenna diversity scheme based on a variety of factor and conveying the determination to the receiving sidelink node.

For example, a wireless communication device may be configured to disable a per-antenna Cyclic Shift Diversity (CSD) insertion for a Long Training Field (LTF) of a Physical Layer (PHY) Protocol Data Unit (PPDU), for example, based on a determination that the PPDU is to be configured for a predefined type of channel-sounding-based measurement. For example, the per-antenna CSD insertion may include insertion of a CSD between a plurality of transmit chains of the wireless communication device. For example, the wireless communication device may be configured to transmit the LTF of the PPDU via the plurality of transmit chains with the per-antenna CSD insertion disabled.

A transmission method includes generating a first precoded signal and a second precoded signal by performing a precoding process on a first baseband signal and a second baseband signal, outputting a third signal by inserting a pilot signal into the first precoded signal, outputting a fourth signal by applying a first phase change to the second precoded signal, outputting a fifth signal by inserting a pilot signal into the fourth signal, and outputting a sixth signal by applying a second phase change to the fifth signal.

Aspects directed towards receiving at a sidelink node from and communicating to peer sidelink nodes an indication on whether the CDD antenna diversity scheme is used in a data transmission are disclosed. Also disclosed is the receiving sidelink node optimizing its operation based on the knowledge of whether the CDD antenna diversity scheme is used in the data transmission and thus the performance at the receiving sidelink node is improved. Also disclosed are aspects directed to a peer sidelink node determining whether to use the CDD antenna diversity scheme based on a variety of factor and conveying the determination to the receiving sidelink node.

Provided are M signal processors that respectively generate modulated signals for M reception apparatuses (where M is an integer equal to 2 or greater), a multiplexing signal processor, and N antenna sections (where N is an integer equal to 1 or greater). When transmitting multiple streams, each of the M signal processors generates two mapped signals, generates first and second precoded signals by precoding the two mapped signals, periodically changes the phase of signal points in the IQ plane with respect to the second precoded signal, outputs the phase-changed signal, and outputs the first precoded signal and the phase-changed second precoded signal as two modulated signals. When transmitting a single stream, each of the M signal processor outputs a single modulated signal. The multiplexing signal processor multiplexes the modulated signals output from the M signal processors, and generates N multiplexed signals. The N antenna sections respectively transmit the N multiplexed signals.