BACKGROUND

Technical Field

The present disclosure is directed to methods, devices and articles in communication systems, such as 3GPP communication systems.

Description of the Related Art

Currently, the 3rd Generation Partnership Project (3GPP) works at the technical specifications for the next generation cellular technology, which is also called fifth generation (5G).

One objective is to provide a single technical framework addressing all usage scenarios, requirements and deployment scenarios (see e.g., section 6 of TR 38.913 version 15.0.0 incorporated herein by reference), at least including enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), massive machine type communication (mMTC).

For example, eMBB deployment scenarios may include indoor hotspot, dense urban, rural, urban macro and high speed; URLLC deployment scenarios may include industrial control systems, mobile health care (remote monitoring, diagnosis and treatment), real time control of vehicles, wide area monitoring and control systems for smart grids; mMTC deployment scenarios may include scenarios with large number of devices with non-time critical data transfers such as smart wearables and sensor networks.

The services eMBB and URLLC are similar in that they both demand a very broad bandwidth, however are different in that the URLLC service may preferably require ultra-low latencies.

A second objective is to achieve forward compatibility. Backward compatibility to Long Term Evolution (LTE, LTE-A) cellular systems is not required, which facilitates a completely new system design and/or the introduction of novel features.

BRIEF SUMMARY

One non-limiting and exemplary embodiment facilitates providing an improved procedure for the mobile terminal to perform downlink control channel receptions and an improved procedure for the base station to perform downlink control channel transmissions.

In one general first example, the techniques disclosed here feature a user equipment comprising a processing circuitry and transceiver. The processing circuitry assumes that a base station is configured to use for downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) transmissions to the mobile terminal one of a plurality of transmission beams (tx-beam #1). The transceiver receives a downlink control channel candidate (PDCCH candidate) and a corresponding demodulation reference signal (DM-RS) from the base station using one of a plurality of reception beams (rx-beam #1) corresponding to the assumed one of the plurality of transmission beams (tx-beam #1). The processing circuitry (130) performs radio channel estimation based on the received demodulation reference signal (DM-RS). The processing circuitry, depending on a radio channel estimation quality, demodulates the downlink control channel candidate (PDCCH candidate) using the radio channel estimation. The channel estimation is performed using a demodulation reference signal sequence which is generated observing an association which is associating the generated sequence with the assumed one of the plurality of transmission beams (tx-beam #1) such that at least two of the plurality of transmission beams are associated with different demodulation reference signal sequences.

In one general first example, the techniques disclosed here feature a base station comprising processing circuitry and a transceiver. The processing circuitry (180) assumes that the mobile terminal is configured to use for downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) receptions at the mobile terminal one of a plurality of reception beams (tx-beam #1). The transceiver (170) transmits a downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) to the mobile terminal using one of a plurality of transmission beams (tx-beam #1) corresponding to the assumed one of the plurality of reception beams (tx-beam #1). The processing circuitry (180) modulates the downlink control channel (PDCCH) to be transmitted and generates a demodulation reference signal sequence to be transmitted as the corresponding demodulation reference signal (DMRS). The demodulation reference signal sequence is generated observing an association which is associating the generated sequence with the one of the plurality of transmission beams (tx-beam #1) such that at least two of the plurality of transmission beams are associated with different demodulation reference signal sequences.

In one general first example, the techniques disclosed here feature a method comprising the following steps performed by a user equipment. The mobile terminal assumes that a base station is configured to use for downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) transmissions to the mobile terminal one of a plurality of transmission beams (tx-beam #1). The mobile terminal receives a downlink control channel candidate (PDCCH candidate) and a corresponding demodulation reference signal (DM-RS) from the base station using one of a plurality of reception beams (rx-beam #1) corresponding to the assumed one of the plurality of transmission beams (tx-beam #1). The mobile terminal performs radio channel estimation based on the received demodulation reference signal (DM-RS) and, depending on a radio channel estimation quality, demodulates the downlink control channel candidate (PDCCH candidate) using the radio channel estimation. The channel estimation is performed using a demodulation reference signal sequence which is generated observing an association which is associating the generated sequence with the assumed one of the plurality of transmission beams (tx-beam #1) such that at least two of the plurality of transmission beams are associated with different demodulation reference signal sequences.

In one general first example, the techniques disclosed here feature a method comprising the following steps performed by a base station. The base station assumes that the mobile terminal is configured to use for downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) receptions at the mobile terminal one of a plurality of reception beams (tx-beam #1). The base station transmits a downlink control channel (PDCCH) and corresponding demodulation reference signal (DM-RS) to the mobile terminal using one of a plurality of transmission beams (tx-beam #1) corresponding to the assumed one of the plurality of reception beams (tx-beam #1). The base station modulates the downlink control channel (PDCCH) to be transmitted and generates a demodulation reference signal sequence to be transmitted as the corresponding demodulation reference signal (DMRS). The demodulation reference signal sequence is generated observing an association which is associating the generated sequence with the one of the plurality of transmission beams (tx-beam #1) such that at least two of the plurality of transmission beams are associated with different demodulation reference signal sequences.

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 thereof.

Additional benefits and advantages of the disclosed embodiments and different implementations will be apparent from the specification and figures. 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.

