A receiver receives and processes a radio signal received via a frequency selective radio channel from a transmitter employing a plurality of transmit antennas. The receiver determines, based on the received signal, complex precoder coefficients and delays of respective space-delay precoders for each layer and transmit antenna at the transmitter so as to achieve a predefined property for a communication over the radio channel, each space-delay precoder modeling or defining for the associated transmit antenna a plurality of cyclic filters delaying and weighting a signal to be transmitted with the corresponding precoder delays and complex precoder coefficients, respectively, and feeds back to the transmitter the determined delays explicitly or implicitly and the determined complex precoder coefficients explicitly or implicitly, the transmitter precoding the signals to be transmitted to the receiver using the fed back delays and complex precoder coefficients.

A method and system are provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) system. The MIMO system may comprise at least one MIMO transmitter and at least one MIMO receiver. Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO communication systems. The method may include generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI.

Transmit diversity schemes may be used for sending sequence-based signals over multiple antennas. For example, a user equipment (UE) may determine an uplink sequence to be transmitted to a base station using multiple antennas. The UE may utilize a transmit diversity scheme for the multiple-antenna transmission of the uplink sequence, where the transmit diversity scheme utilized may be based on a number of symbol periods during which the sequence is transmitted. In accordance with the transmit diversity scheme, the UE may use multiple transmit antennas to transmit different sequences from respective antennas. In other examples, the UE may transmit the uplink sequence using different time or frequency resources. Additionally, the UE may use some combination of different transmit diversity schemes for sequence-based signals. In some aspects, the base station may provide an indication of the transmit diversity scheme that the UE is to use for transmitting the uplink sequence.

Systems and methods for closed loop MIMO (multiple input and multiple output) wireless communication are provided. Various transmit formats including spatial multiplexing and STTD are defined in which vector or matrix weighting is employed using information fed back from receivers. The feedback information may include channel matrix or SVD-based feedback.

A receiver receives and processes a radio signal received via a frequency selective radio channel from a transmitter employing a plurality of transmit antennas. The receiver determines, based on the received signal, complex precoder coefficients and delays of respective space-delay precoders for each layer and transmit antenna at the transmitter so as to achieve a predefined property for a communication over the radio channel, each space-delay precoder modeling or defining for the associated transmit antenna a plurality of cyclic filters delaying and weighting a signal to be transmitted with the corresponding precoder delays and complex precoder coefficients, respectively, and feeds back to the transmitter the determined delays explicitly or implicitly and the determined complex precoder coefficients explicitly or implicitly, the transmitter precoding the signals to be transmitted to the receiver using the fed back delays and complex precoder coefficients.

Aspects of the present invention provide additional MAC functionality to support the PHY features of a wireless communication system framework. The additional MAC functionality aids in enabling feedback from wireless terminals to base stations. In some aspects of the invention the feedback is provided on an allocated feedback channel. In other aspects of the invention the feedback is provided by MAC protocol data units (PDU) in a header, mini-header, or subheader. The feedback may be transmitted from the wireless terminal to the base station autonomously by the wireless terminal or in response to an indication from the base station that feedback is requested. Aspects of the invention also provide for allocating feedback resources to form a dedicated feedback channel. One or more of these enhancements is included in a given implementation. Base stations and wireless terminals are also described upon which methods described herein can be implemented.

The disclosure relates to a first communication device for a wireless communication system, the first communication device comprising: a processor, a cascade precoder including an outer precoder and an inner precoder, and a transceiver; wherein the processor is configured to determine the inner precoder; wherein the transceiver is configured to transmit a first pilot sequence to a second communication device; wherein the transceiver is configured to receive a first channel estimation from the second communication device; wherein the processor is configured to determine the outer precoder based on the first channel estimation; wherein the transceiver is configured to transmit at least one of a data sequence and a pilot sequence to the second communication device.

A method for X2 interface communication is disclosed, comprising: at an X2 gateway for communicating with, and coupled to, a first and a second radio access network (RAN), receiving messages from the first RAN according to a first X2 protocol and mapping the received messages to a second X2 protocol for transmission to the second RAN; maintaining state of one of the first RAN or the second RAN at the X2 gateway; executing executable code received at an interpreter at the X2 gateway as part of the received messages; altering the maintained state based on the executed executable code; and receiving and decoding an initial X2 message from the first RAN; identifying specific strings in the initial X2 message; matching the identified specific strings in a database of stored scripts; and performing a transformation on the initial X2 message, the transformation being retrieved from the database for stored scripts, the stored scripts being transformations.

Described is a technology to reduce the interference between two or more transmit receive (Tx/Rx) points (TRPs) and improve the reliability for New Radio ultra reliable low latency communication (NR URLLC) applications. The technology operates in one aspect at a network node, and in another aspect at a user equipment. If a network device decides to use packet duplication, the network device can indicate duplication to the user equipment. The network device can send duplicate copies, e.g., via two different antenna panels, or can send one copy and coordinate with another network device (e.g., another cell) to send the other copy. When the user equipment receives the copies, the user equipment combines the data, e.g., via soft combining or concatenation into combined data, and decodes the combined data. Weights, such as corresponding to channel quality from each transmit source, can be used as factors in the combining of the data.

A test transmission can be used to train and/or select a signal. For example, a cellular network can configure a receiver with a recommended receiver signal sweeping pattern for mobile devices. A transmitter device can duplicate a data packet transmission and send it to a receiver device to ensure that the receiver can receive the duplicated packets from different signals. Consequently, the duplicated data packet can be indicated in the associated control channel so that the receiver is aware that the data packet is a duplicated transmission, and based on this info and configuration data, the receiver can select a more favorable signal.