TECHNICAL FIELD

The present disclosure relates to a transmitter, a receiver, a transmission method, and a reception method.

BACKGROUND ART

A communication system called “fifth-generation mobile communication system (5G)” has been under consideration. In 5G, flexible provision of a function to each of various use cases where an increase in communication traffic, an increase in the number of terminals to be connected, high reliability, low latency, and the like are needed has been under consideration. There are three typical use cases: enhanced Mobile Broadband (eMBB), Massive Machin Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). In 3GPP (3rd Generation Partnership Project), which is an international standardization organization, sophistication of communication systems has been under consideration from the embodiment of both sophistication of LTE systems and New RAT (Radio Access Technology) (see, for example, NPL 1).

CITATION LIST

Non Patent Literature

NPL 1: RP-161596, “Revision of SI: Study on New Radio Access Technology”, NTT DOCOMO, September 2016

NPL 2: R1-1612335, “On phase noise effects”, Ericsson, November 2016

SUMMARY OF INVENTION

In New RAT, as compared with LTE/LTE-Advanced, signals of high frequencies of, for example, 6 GHz or higher are utilized as carrier waves. In particular, in a case where a high frequency band and a higher-order modulation multivalued number (modulation order) are used, error rate characteristics deteriorate due to a CPE (common-phase error) or ICI (inter-carrier interference) that occurs due to the phase noise of a local oscillator of a transmitter (see, for example, NPL 2). To address this problem, New RAT has given consideration to a receiver's performing a CPE correction or ICI correction (hereinafter sometimes referred to as “CPE/ICI correction”) by means of a phase tracking reference signal (PT-RS) in addition to performing channel equalization.

However, no close consideration has been given to a method for suppressing interference with PT-RSs that are transmitted from a plurality of base stations (BSs; sometimes referred to as “gNBs”) or a plurality of mobile stations (terminals; sometimes referred to as “UEs (pieces of user equipment)”).

An embodiment of the present disclosure facilitates providing a transmitter, a receiver, a transmission method, and a reception method that can appropriately suppress interference with PT-RSs that are transmitted from a plurality of base stations or mobile stations.

According to an embodiment of the present disclosure, there is provided a transmitter including an assignment circuit that maps a phase tracking reference signal onto a subcarrier and a transmitting circuit that transmits a signal containing the phase tracking reference signal. The phase tracking reference signal is mapped onto a different subcarrier for each cell, group, or mobile station.

According to an embodiment of the present disclosure, there is provided a receiver including a receiving circuit that receives a signal containing a phase tracking reference signal and a demodulating circuit that demodulates a data signal by using a phase noise estimated value calculated using the phase tracking reference signal. The phase tracking reference signal is mapped onto a different subcarrier for each cell, group, or mobile station.

According to an embodiment of the present disclosure, there is provided a transmission method including mapping a phase tracking reference signal onto a subcarrier and transmitting a signal containing the phase tracking reference signal. The phase tracking reference signal is mapped onto a different subcarrier for each cell, group, or mobile station.

According to an embodiment of the present disclosure, there is provided a reception method including receiving a signal containing a phase tracking reference signal and demodulating a data signal by using a phase noise estimated value calculated using the phase tracking reference signal. The phase tracking reference signal is mapped onto a different subcarrier for each cell, group, or mobile station.

It should be noted that general or specific embodiments may be implemented as a system, a method, an integrated circuit, a computer program, a storage medium, or any selective combination of a method, an apparatus, an integrated circuit, a computer program, and a storage medium.

An embodiment of the present disclosure makes it possible to appropriately suppress interference with PT-RSs that are transmitted from a plurality of base stations or mobile stations.

Additional benefits and advantages of the disclosed embodiments will become apparent from the specification and drawings. The benefits and/or advantages may be individually obtained by the various embodiments and features of the specification and drawings, which need not all be provided in order to obtain one or more of such benefits and/or advantages.

