Method for determining a transmission direction for a communication, a method for determining a precoding matrix for a communication, and a device configured to do the same

#Various aspects relate to a method for determining a transmission direction for a communication of a network component of a radio communications system, a method for determining a precoding matrix for a communication of a network component of a radio communications system, and a device configured to do the same.

#Precoding is a technique by which each data stream at a network component (e.g. a base station) is weighted. Precoding may increase or maximize data throughput in a communications channel between the network component and a terminal (e.g. a UE). In multiple-input multiple-output (MIMO) systems, precoding may be a component of closed-loop link adaptation, whereby a transmit signal at the network component may be modified based on channel state information.

#Precoding may be achieved by means of a matrix-multiplication of a given signal vector with a precoding matrix prior to transmission (e.g. by the network component). The precoding matrix may be determined based on a codebook of candidate precoding matrices. A size of the codebook (namely, the number of candidate precoding matrices) may be large, e.g. for communication systems or operation modes that may require accurate precoding. Determining the precoding matrix based on a large codebook of candidate precoding matrices may result in a significant computation load for a device configured to determine the precoding matrix, especially for such devices with tight limits on computational capacity and power consumption budget. Therefore, efficient ways of determining the precoding matrix are needed.

#In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various aspects of the invention are described with reference to the following drawings, in which:

#FIG. 1 shows a communications system.

#FIG. 2 shows a block diagram of a terminal and a network component.

#The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and aspects in which the invention may be practised. These aspects are described in sufficient detail to enable those skilled in the art to practice the invention. Other aspects may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. The various aspects are not necessarily mutually exclusive, as some aspects can be combined with one or more other aspects to form new aspects. Various aspects are described for structures or devices, and various aspects are described for methods. It may be understood that one or more (e.g. all) aspects described in connection with structures or devices may be equally applicable to the methods, and vice versa.

#The word “exemplary” is used herein to mean “serving as an example, instance, or illustration”. Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs.

#The term “radio communications network” is used herein to refer to a radio communications system configured in accordance with the network architecture of any one of, or any combination of, LTE (Long Term Evolution) cellular communications technology, UMTS (Universal Mobile Telecommunications System) cellular communications technology which may include the system enhancement HSPA (High Speed Packet Access), GSM (Global System for Mobile Communications) cellular communications technology which may include system enhancements General Packet Radio System (GPRS) and Enhanced Data rates for GSM Evolution (EDGE) and CDMA2000 (Code Division Multiple Access) cellular communications technology, although other radio communications technology may be possible as well.