The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

Apparatuses, methods, and systems for precoding multi-carrier signals are disclosed. One method includes obtaining a transmission channel matrix between a terminal and a plurality of separate users, wherein the transmission channel matrix includes channel estimates for a plurality of subcarriers of the multi-carrier signal, wherein the terminal is one of a plurality of terminals interfaced with a central processing unit, and wherein the terminal communicates with the plurality of spatially separate user with the multi-carrier signals. The method further comprises determining a precoding for the terminal based on a distribution of user signal power across the transmission channel between the terminal and the plurality of spatially separate user, and determining a precoding for the central processing unit based on the precoding for the terminal and based on the transmission channel matrix, wherein a precoding matrix for the central processing unit is multi-carrier signal dependent.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

Aspects of the disclosure relate to multiple-input and multiple-output (MIMO) codebook configuration for wireless downlink communications. A user equipment or a scheduled entity receives a reference signal (channel state information reference signal (CSI-RS) and transmits a CSI report based on the reference signal. The CSI report includes a rank indicator configured to indicate one or more ranks among multiple ranks corresponding to multiple antenna panels associated with the reference signal, and a precoding matrix indicator (PMI) corresponding to a codebook for the plurality of antenna panels. In some examples, a first rank of the multiple ranks is different from a second rank of the plurality of ranks. In other examples, a first antenna panel of the multiple antenna panels having a different number of antenna ports than a second antenna panel of the multiple antenna panels. Other aspects, embodiments, and features are also claimed and described.

Apparatuses, methods, and systems for precoding multi-carrier signals are disclosed. One method includes obtaining a transmission channel matrix between a terminal and a plurality of separate users, wherein the transmission channel matrix includes channel estimates for a plurality of subcarriers of the multi-carrier signal. A channel dimension reduction matrix is determined based upon a composite of the channel estimates for the plurality of subcarriers, wherein dimensions of the channel dimension reduction matrix are less than dimensions of the transmission channel matrix. The method further includes determining a precoding matrix for the terminal based on the channel dimension reduction matrix, wherein the precoding matrix is multi-carrier signal independent, determining an effective channel based on a channel estimate of the transmission channel and based on the precoding matrix of the terminal, and determining a precoding matrix for the central processing unit based on the effective channel.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

A method for transmitting and receiving a codebook subset restriction bitmap is provided. The Codebook Subset Restriction (CSR) bitmap transmission method of an evolved Node B (eNB) in transmission mode 9 for communication with 8 antenna ports includes generating a CSR bitmap including bits corresponding to restricted precoding matrix indicators and rank indicators that are not allowed for reporting and transmitting the CSR bitmap to a User Equipment (UE). The CSR bitmap comprises 53 bits corresponding to a first codebook and 56 bits corresponding to a second codebook, the 53 bits corresponding to a first codebook comprise 16, 16, 4, 4, 4, 4, and 1 bits for layers 1, 2, 3, 4, 5, 6, 7, and 8, respectively, and the 56 bits corresponding to a second codebook comprise 16, 16, 16 and 8 bits for layers 1, 2, 3, and 4, respectively.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.

The present disclosure provides a method of generating codebook in a wireless communication system with multiple antenna arrays, as well as a wireless communication system, base station and terminal using the codebook for communication. The method comprises steps of: providing a basic codebook which contains multiple pre-coding matrices; and assigning phase offsets to certain pre-coding matrices in the basic codebook to form a codebook with phase offset. The feedback overhead from a client to a base station side is reduced and a good precision of feedback for multi-antenna array is kept by applying the method of generating codebook and using the generated codebook in the wireless communication system, base station and terminal.