Method and apparatus for detecting spurious control information

Patent metadata

Field	Value
Publication number	US-10164754-B1
Application number	US-201715467377-A
Country	US
Kind code	B1
Filing date	Mar 23, 2017
Priority date	Feb 4, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

In order to support low latency and bursty internet data traffic, the 3GPP LTE wireless communication system uses dynamic allocation. To keep the allocation overhead lower, the system is designed such that the client terminal must perform a number of decoding attempts to detect resource allocations. During course of the decoding attempts a false resource allocation may be decoded by the client terminal. The false detection may lead to multiple issues for the performance efficiency of the client terminal and the overall communication system. A method and apparatus are disclosed than enable the detection of false resource allocation. This in turn improves the performance and efficiency of the client terminal and the wireless communication system.

First claim

The invention claimed is:

1. A computer-implemented method of detecting false downlink control information in a wireless communication system, the method comprising:
determining, by one or more processors, whether a physical downlink control channel (PDCCH) candidate has been successfully decoded at a first aggregation level of a particular tree structure;
when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skipping PDCCH candidates at a second, higher, aggregation level within the particular tree structure, such that the skipped PDCCH candidates are not decoded;
performing, by the one or more processors, duplicate PDCCH detection;
when the detection determines that the PDCCH candidate is not a duplicate of a given PDCCH candidate previously successfully decoded, extracting a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and
determining whether the HARQ process identity is outside a HARQ process identity range.

2. The method of claim 1 , wherein when the detection determines that the PDCCH candidate is a duplicate, declaring the PDCCH candidate a duplicate and discarding it.

3. The method of claim 1 , wherein performing the duplicate PDCCH detection includes checking whether a decoded PDCCCH message is identical to another successfully decoded message of the same length.

4. The method of claim 1 , wherein performing the duplicate PDCCH detection includes checking whether a cyclic redundancy check (CRC) of a decoded PDCCH message is identical to the CRC of a previously decoded PDCCH message.

5. The method of claim 1 , further comprising:
when the HARQ process identity is determined to be within the HARQ process identity range,
extracting new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message;
determining whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and
when it is determined that the extracted NDI field has toggled, checking the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI.

6. The method of claim 5 , further comprising:
when it is determined that the extracted NDI field has not toggled, determining whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and
when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identifying the received DCI as the true DCI.

7. A processing system configured to detect false downlink control information in a wireless communication network, the system comprising:
memory configured to store information associated one or more physical downlink control channels (PDCCH); and
one or more processors coupled to the memory and configured to:
determine whether a PDCCH candidate has been successfully decoded at a first aggregation level of a particular tree structure;
when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skip PDCCH candidates at a second, higher, aggregation level within the particular tree structure, such that the skipped PDCCH candidates are not decoded;
perform duplicate PDCCH detection;
when the detection determines that the PDCCH candidate is not a duplicate of a given PDCCH candidate previously successfully decoded, extract a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and
determine whether the HARQ process identity is outside a HARQ process identity range.

8. The processing system of claim 7 , wherein the one or more processors are further configured to, when the HARQ process identity is determined to be within the HARQ process identity range:
extract new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message;
determine whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and
when it is determined that the extracted NDI field has toggled, check the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI.

9. The processing system of claim 8 , wherein the one or more processors are further configured to:
when it is determined that the extracted NDI field has not toggled, determine whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and
when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identify the received DCI as the true DCI.

10. A wireless communication device configured to detect false downlink control information in a wireless communication network, the device comprising:
a transceiver configured to receive downlink control information;
memory configured to store information associated with one or more physical downlink control channels (PDCCH);
a PDCCH decoder configured to perform PDCCH decoding; and
one or more processors operatively coupled to the transceiver, the memory and the PDCCH decoder, the one or more processors being configured to:
determine whether a PDCCH candidate has been successfully decoded at a first aggregation level of a particular tree structure;
when it is determined that the PDCCH candidate has been successfully decoded at the first aggregation level of the particular tree structure, skip PDCCH candidates at a second, higher, aggregation level within the particular tree structure, such that the skipped PDCCH candidates are not decoded;
perform duplicate PDCCH detection;
when the detection determines that the PDCCH candidate is not a duplicate of a given PDCCH candidate previously successfully decoded, extract a hybrid automatic repeat request (HARQ) process identity from a downlink control information (DCI) message; and
determine whether the HARQ process identity is outside a HARQ process identity range.

11. The device of claim 10 , wherein the one or more processors are further configured to, when the HARQ process identity is determined to be within the HARQ process identity range:
extract new data indicator (NDI) and modulation and coding scheme (MCS) fields from the DCI message;
determine whether the extracted NDI field has toggled compared to an NDI value in a last received DCI for a same HARQ process identity; and
when it is determined that the extracted NDI field has toggled, check the value of the MCS field to determine whether it satisfies a predetermined threshold such that the received DCI is a true DCI.

12. The device of claim 11 , wherein the one or more processors are further configured to:
when it is determined that the extracted NDI field has not toggled, determine whether the extracted MCS satisfies the predetermined threshold and whether any DCI for the same HARQ process identity was previously received with the same MCS value; and
when the extracted MCS value and any DCI for the same HARQ process identity was previously received with the same MCS value, identify the received DCI as the true DCI.

Assignees

• Mbit Wireless Inc

Inventors

• Patel Bhaskar
• Govindswamy Arumugam

Classifications

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title

• H04L5/0091 Primary

  Signalling for the administration of the divided path, e.g. signalling of configuration information · CPC title

• H04L1/1812

  Hybrid protocols; Hybrid automatic repeat request [HARQ] · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title