Base station unit and method for radio communication

• US 20020123351A1
• Filed: 02/27/2002
• Published: 09/05/2002
• Est. Priority Date: 07/03/2000
• Status: Active Grant

• Current Assignee: INVT SPE LLC (SoftBank Group Corp.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Miyoshi, Kenichi, Aoyama, Takahisa
• Granted Patent: US 6,847,828 B2
• Time in Patent Office: Days
• US Class Current: 455/452.2
• CPC Class Codes: H04B 17/336 Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR]
• CPC Class Codes: H04B 17/373 Predicting channel quality or other radio frequency [RF] parameters
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/002 Algorithms with memory of the previous states, e.g. Markovian models
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0033 arrangements specific to the transmitter
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/221 using past power control commands
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/241 taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/247 where the output power of a terminal is based on a path parameter sent by another terminal
• CPC Class Codes: H04W 52/262 taking into account adaptive modulation and coding [AMC] scheme AMC per se H04L1/0001
• CPC Class Codes: H04W 52/32 TPC of broadcast or control channels

Abstract

An SIR information extracting section 106 extracts SIR measured at a communication terminal from the received data, and a fluctuation amount calculating section 109 calculates a fluctuation amount of SIR between time at which the communication terminal has measured SIR and transmission starting time of DSCH data using a TPC command, and a. transmission system determining section 110 adds the SIR fluctuation amount calculated in the fluctuation amount calculating section 109 to the SIR measured at the communication terminal and estimates SIR of DSCH data so as to determine an optimal transmission system of DSCH data according to the estimated SIR.

Claims

1. A base station apparatus, comprising:

a capturer for capturing a channel condition measured at a communication terminal at a former time rather than a transmission starting time of data of a common channel shared by a plurality of communication terminals;

a detector for detecting a fluctuation of the channel condition between the former time and the transmission starting time;

an estimator for estimating the channel condition captured by said capturer at the transmission starting time based on the fluctuation of the channel condition in addition to the channel condition; and

a transmitter for transmitting the data of the common channel to the communication terminal using an optimal transmission system according to the channel condition estimated by said estimator.

2. The base station apparatus according to claim 1, wherein said capturer captures the channel condition notified from the communication terminal per a predetermined transmission unit, and wherein said detector detects the fluctuation of the channel condition using plural information on transmit power control notified from the communication terminal per transmission unit shorter than the predetermined transmission unit.

3. The base station apparatus according to claim 1, wherein said detector detects the fluctuation of the channel condition using information on transmit power control for a channel excluding the common channel.

4. The base station apparatus according to claim 1, wherein said transmitter comprises a coder for coding the data of the common channel using an optimal coding scheme according to the channel condition estimated by said estimator.

5. The base station apparatus according to claim 1, wherein said transmitter comprises a modulator for modulating the data of the common channel using an optimal modulating scheme according to the channel condition estimated by said estimator.

6. The base station apparatus according to claim 1, wherein said transmitter comprises a controller for controlling a transmit power of the data of the common channel to an optimal transmit power according to the channel condition estimated by said estimator.

7. A radio communication method, comprising:

a capturing step of capturing a channel condition measured at a communication terminal at a former time rather than a transmission starting time of data of a common channel shared by a plurality of communication terminals;

a detecting step of detecting a fluctuation of the channel condition between the former time and the transmission starting time;

an estimating step of estimating the channel condition captured at the capturing step at the transmission starting time based on the fluctuation of the channel condition in addition to the channel condition; and

a transmitting step of transmitting the data of the common channel to the communication terminal using an optimal transmission system according to the channel condition estimated at the estimating step.

8. The radio communication method according to claim 7, wherein at the capturing step, capturing the channel condition notified from the communication terminal is performed per a predetermined transmission unit, and wherein at the detecting step, detecting the fluctuation of the channel condition is performed using plural information on transmit power control notified from the communication terminal per transmission unit shorter than the predetermined transmission unit.

9. The radio communication method according to claim 7, wherein at the detecting step, detecting the fluctuation of the channel condition is performed using information on transmit power control for a channel excluding the common channel.