Receiving apparatus, data receiving method, and channel estimating apparatus and method therefor

Patent metadata

Field	Value
Publication number	US-9444652-B2
Application number	US-201214112265-A
Country	US
Kind code	B2
Filing date	Apr 20, 2012
Priority date	Apr 22, 2011
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

In the present disclosure, the UE apparatus is classified by type and the demodulation information to use in channel estimation of MUI signals is determined based on the type of the UE apparatus. The channel estimating apparatus for MUI signals has: a user type determining circuit that determines whether a UE apparatus corresponding to an own station belongs to a first type user or a second type user and determines demodulation information to use in channel estimation of MUI signals based on the type of the UE apparatus corresponding to the own station; and a channel estimating circuit that performs channel estimation of a multi-user interference signal based on the determined demodulation information to use in channel estimation of MUI signals. With this structure, it is possible to improve channel estimation accuracy and further to improve the performance of data reception and user and cell throughputs.

First claim

The invention claimed is:

1. A receiving apparatus comprising:
a demodulation information obtaining circuit that extracts demodulation information of an own station from a physical downlink control channel (PDCCH) of a reception signal;
a user type determining circuit that
determines whether a UE apparatus corresponding to the own station belongs to a first type user or a second type user,
wherein the first type user is a UE apparatus that only knows its own data demodulation information and does not know whether or not there exists another UE apparatus in a present coordinated transmission group and during data reception, a base station transmits data in a maximum number of data streams that share same frequency resources
and the second type user is a UE apparatus that recognizes not only its own data demodulation information but also demodulation information of other UE apparatuses in the present coordinated transmission group and during the data reception, the base station transmits data in fewer than the maximum number of data streams that share the same frequency resources, and

determines demodulation information to use in channel estimation of multi-user interference signals based on whether the UE apparatus corresponding to the own station belongs to the first type user or the second type user;

a first channel estimating circuit that performs channel estimation of a downlink data channel of the own station based on the demodulation information of the own station;
a second channel estimating circuit that performs channel estimation of a multi-user interference signal in the reception signal based on the determined demodulation information to use in channel estimation of multi-user interference signals;
a third channel estimating circuit that performs channel estimation of an inter-cell interference signal in the reception signal;
a reception coefficient generating circuit that generates a reception coefficient based on channel estimation results of the first channel estimating circuit, the second channel estimating circuit and the third channel estimating circuit; and
a data detecting circuit that performs data detection on a physical downlink shared channel (PDSCH) of the reception signal based on the generated reception coefficient.

2. The receiving apparatus of claim 1 , wherein the user type determining circuit comprises:
a reference signal measuring circuit that measures reference signal reception power (RSRP) or reference signal reception quality (RSRQ) of a serving base station of the own station in the reception signal and RSRP or RSRQ of a neighbor cell;
a first user type determining circuit that compares the RSRP or RSRQ of the serving base station of the own station with the RSRP or RSRQ of the neighbor cell and, when a difference between the RSRP or RSRQ of the serving base station of the own station and a maximum value of the RSRP or RSRQ of the neighbor cell is equal to or greater than a predetermined threshold, determines that the own station belongs to the first type user and when the difference between the RSRP or RSRQ of the serving base station and the maximum value of the RSRP or RSRQ of the neighbor cell is smaller than the predetermined threshold, determines that the own station belongs to the second type user; and
a first demodulation information determining circuit that, when it is determined that the own station belongs to the first type user, determines all combinations of DM-RS (demodulation reference signal) port ID and SCID (scramble sequence index) excluding DM-RS port ID and SCID used by the own station as the demodulation information to use in channel estimation of multi-user interference signals and, when it is determined that the own station belongs to the second type user, determines null as the demodulation information to use in channel estimation of multi-user interference signals.

3. The receiving apparatus of claim 1 , wherein the user type determining circuit comprises:
a second user type determining circuit that determines whether the own station belongs to the first type user or the second type user based on the demodulation information of the own station; and
a second demodulation information determining circuit that, when it is determined that the own station belongs to the first type user, determines all combinations of DM-RS port ID and SCID excluding a DM-RS port ID and an SCID used by the own station as the demodulation information to use in channel estimation of multi-user interference signals and, when it is determined that the own station belongs to the second type user, determines the demodulation information to use in channel estimation of multi-user interference signals based on the demodulation information of the own station.

4. The receiving apparatus of claim 3 , wherein the second user type determining circuit determines whether the DM-RS port ID of the own station is greater than a predetermined threshold or not and whether the SCID of the own station is 1 or not, when the DM-RS port ID of the own station is greater than the predetermined threshold and the SCID is 1, the second user type determining circuit determines that the own station belongs to the first type user and when the DM-RS port ID of the own station is greater than the predetermined threshold and the SCID is not 1, the second user type determining circuit determines that the own station belongs to the second type user, and when it is determined that the own station belongs to the second type user, the second demodulation information determining circuit determines, as the demodulation information to use in channel estimation of multi-user interference signals, combinations of DM-RS port ID and SCID such that the DM-RS port ID and the SCID is smaller than the DM-RS port ID and the SCID used by the own station.

5. The receiving apparatus of claim 3 , wherein the second user type determining circuit determines whether the DM-RS port ID is greater than a predetermined threshold or not, when it is determined that the DM-RS port ID is greater than the predetermined threshold, the second user type determining circuit determines that the own station belongs to the first type user and when it is determined that the DM-RS port ID is not greater than the predetermined threshold, the second user type determining circuit determines that the own station belongs to the second type user, and when it is determined that the own station belongs to the second type user, the second demodulation information determining circuit determines, as the demodulation information to use in channel estimation of multi-user interference signals, combinations of DM-RS port ID and SCID such that the DM-RS port ID is smaller than the DM-RS port ID used by the own station and the SCID is any SCID.

6. The receiving apparatus of claim 3 , wherein the second user type determining circuit determines whether the SCID is 1 or not, when it is determined that the SCID is 1, the second user type determining circuit determines that the own station belongs to the first type user and when the SCID is not 1, the second user type determining circuit determines that the own station belongs to the second type user, and when it is determined that the own station belongs to the second type user, the second demodulation information determining circuit determines, as the demodulation information to use in channel estimation of multi-user interference signals, combinations of DM-RS port ID and SCID such that the SCID is 0 and the DM-RS port ID is smaller than the DM-RS port ID used by the own station.

7. A channel estimating apparatus for multi-user interference (MUI) signals, comprising:
a user type determining circuit that determines whether a UE apparatus corresponding to an own station belongs to a fi

Assignees

• Nagata Satoshi
• Taoka Hidekazu
• Zhu Jianchi
• She Xiaoming
• Chen Lan
• Ntt Docomo Inc

Inventors

• Nagata Satoshi
• Taoka Hidekazu
• Zhu Jianchi
• She Xiaoming
• Chen Lan

Classifications

• H04L25/0202 Primary

  Channel estimation · CPC title

• H04L25/0204

  of multiple channels · CPC title

• H04L25/03891

  Spatial equalizers (MIMO diversity systems H04B7/0413) · CPC title

• H04J11/005

  of intercell interference · CPC title

• H04J11/0036 Primary

  at the receiver · CPC title