Method and apparatus for transmitting codebook-based signal in wireless communication system

A user equipment for transmitting channel status information in a wireless communication system, the user equipment comprising:

• a receiver;
• a transmitter;
• and
• a processor,
• wherein the processor is configured to:
• measure a downlink channel from a downlink signal received from a base station through the receiver,
• determine a first precoding matrix indicator (PMI) and a second PMI of the downlink channel based on a measurement of the downlink channel, and
• transmit the first PMI and the second PMI to the base station by using the transmitter,
• wherein:
• the first PMI indicates a first precoding vector including a first elevation angle component of a multi-antenna of the base station,
• the second PMI indicates a second precoding vector including a second elevation angle component and an azimuth angle component of the multi-antenna of the base station, and
• the second elevation angle component is determined based on a value of the first elevation angle component, and
• wherein a2+b2=1, where ‘a’ is the first elevation angle component, and ‘b’ is the second elevation angle component.

A method for receiving channel status information at a base station in a wireless communication system, the method comprising:

• transmitting a downlink signal, which is used for a measurement of a downlink channel of a user equipment, to a user equipment;
• and
• receiving a first precoding matrix indicator (PMI) and a second PMI determined based on the measurement of the downlink channel from the user equipment, wherein:
• the first PMI indicates a first precoding vector including a first elevation angle component of a multi-antenna of the base station,
• the second PMI indicates a second precoding vector including a second elevation angle component and an azimuth angle component of the multi-antenna of the base station, and
• the second elevation angle component is determined based on a value of the first elevation angle component, and
• wherein a2+b2=1, where ‘a’ is the first elevation angle component, and ‘b’ is the second elevation angle component.

A base station for receiving channel status information in a wireless communication system, the base station comprising:

• a receiver;
• a transmitter;
• and
• a processor,
• wherein the processor is configured to:
• transmit a downlink signal, which is used for a measurement of a downlink channel of a user equipment, to a user equipment by using the transmitter, and
• receive a first precoding matrix indicator (PMI) and a second PMI determined based on the measurement of the downlink channel from the user equipment by using the receiver,
• wherein:
• the first PMI indicates a first precoding vector including a first elevation angle component of a multi-antenna of the base station,
• the second PMI indicates a second precoding vector including a second elevation angle component and an azimuth angle component of the multi-antenna of the base station, and
• the second elevation angle component is deteanined based on a value of the first elevation angle component, and
• wherein a2+b2=1, where ‘a’ is the first elevation angle component, and ‘b’ is the second elevation angle component.