Radio communication apparatus for feeding back radio link quality information
AssigneeFujitsu Limited
InventorDai Kimura
Life of this patent
Estimating the term…
Abstract
A base station has a time correlation calculating unit for estimating a variation-with-time characteristic of radio link quality using radio downlink quality information reported by a mobile station, a target error rate setting unit for changing over a target error rate adaptively using this variation-with-time characteristic, and an MCS decision unit for deciding a modulation scheme and/or encoding rate, in such a manner that packet error rate becomes equal to the target error rate, using the radio link quality information as well as reception success/failure information reported by the mobile station. The base station transmits a packet based upon the modulation scheme and/or encoding rate decided.
Claims10
A radio communication apparatus in a radio packet communication system for feeding back radio link quality information, which has been measured on a packet receiving side, to a transmitting side and adaptively controlling a modulation scheme and/or encoding rate on the transmitting side using the quality information, comprising:
- estimating means for estimating a variation-with-time characteristic of the radio link quality using the radio link quality information reported by the packet receiving side;
- changeover means for adaptively changing over a target error rate using the variation-with-time characteristic;
- deciding means for deciding a modulation scheme and/or encoding rate, in such a manner that packet error rate becomes equal to the target error rate, using the radio link quality information as well as reception success/failure information reported by the packet receiving side;
- and
- means for transmitting a packet based upon the modulation scheme and/or encoding rate decided;
- wherein said estimating means estimates the variation-with-time characteristic of the radio link quality by calculating correlation of the radio link quality at prescribed time intervals.
A radio communication apparatus in a radio packet communication system for feeding back radio link quality information, which has been measured on a packet receiving side, to a transmitting side and adaptively controlling a modulation scheme and/or encoding rate on the transmitting side using the quality information, comprising:
- estimating means for estimating a variation-with-time characteristic of the radio link quality using a pilot symbol received from the packet receiving side;
- changeover means for adaptively changing over a target error rate using the variation-with-time characteristic;
- deciding means for deciding a modulation scheme and/or encoding rate, in such a manner that packet error rate becomes equal to the target error rate, using the radio link quality information as well as reception success/failure information reported by the packet receiving side;
- and
- means for transmitting a packet based upon the modulation scheme and/or encoding rate decided;
- wherein said estimating means estimates the variation-with-time characteristic of the radio link quality by calculating correlation of a receive pilot symbol at prescribed time intervals.
A radio communication apparatus in a radio packet communication system for feeding back radio link quality information, which has been measured on a packet receiving side, to a transmitting side and adaptively controlling a modulation scheme and/or encoding rate on the transmitting side using the quality information, comprising:
- estimating means for estimating throughput on the packet receiving side;
- control means for adaptively controlling a target error rate so as to maximize the throughput;
- means for deciding a modulation scheme and/or encoding rate, in such a manner that average error rate of a packet becomes equal to the target error rate, using the radio link quality information as well as reception success/failure information reported by the packet receiving side;
- and
- means for transmitting a packet based upon the modulation scheme and/or encoding rate decided,
- wherein said estimating means estimates throughput THP in accordance with the following equation:
- THP=<TBS>×(1−PER)
- where <TBS> represents the average value of transport block size and PER represents the target error rate.
A radio communication apparatus in a radio packet communication system for feeding back radio link quality information, which has been measured on a packet receiving side, to a transmitting side and adaptively controlling a modulation scheme and/or encoding rate on the transmitting side using the quality information, comprising:
- estimating means for estimating a variation-with-time characteristic of the radio link quality using a pilot symbol received from the packet transmitting side;
- changeover means for adaptively changing over a target error rate using the variation-with-time characteristic;
- means for receiving a radio packet, which has undergone error detection and encoding, and performing error detection;
- means for measuring a radio link quality value using the pilot symbol received;
- means for correcting the radio link quality value using result of the error detection in such a manner that packet error rate becomes equal to the target error rate;
- and
- means for reporting the corrected radio link quality value to a packet transmitting side as said radio link quality information;
- wherein said estimating means estimates the variation-with-time characteristic of the radio link quality by calculating correlation of a receive pilot symbol at prescribed time intervals.
Dependencies are inferred from the claim text.