Radio communication device and semiconductor integrated circuit device used for the same

• US 20060188004A1
• Filed: 01/27/2006
• Published: 08/24/2006
• Est. Priority Date: 01/27/2005
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Shobatake, Yasuro, Shigeta, Yoshinori, Kizu, Toshiki, Shimojo, Yoshimitsu
• Application Number:
  US11/340,853
• Publication Number:
  US 20060188004A1
• Time in Patent Office: Days
• US Class Current: 375/132
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 1/7136 Arrangements for generation of hop frequencies, e.g. using a bank of frequency sources, using continuous tuning or using a transform
• CPC Class Codes: H04B 1/715 Interference-related aspects
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 7/0054 Detection of the synchronisation error by features other than the received signal transition by means of signal transition H04L7/033
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/542 using measured or perceived quality
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A semiconductor integrated circuit for a radio communication terminal sequentially uses a plurality of frequency channels by instructions from a hopping frequency decision unit to receive packet data by a reception unit. When the integrated circuit cannot detect the head of the packet data in reception operations, the integrated circuit cannot receive packet data should be received originally then assumes that the received packet data is a packet error. And the integrated circuit calculates packet error rates for each frequency channel on the basis of the number of times of reception operations performed for each frequency channel and of the number of times of packet errors to estimate channel qualities by using the packet error rates.

Claims

1. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel;

a error detection unit which assumes that there are packet errors incapable of receiving the packet data to be originally received because of deterioration of a channel quality if a head of the packet data could not be detected at the time when the reception unit performed reception operations of the packet data; and

a control unit which estimates channel qualities of the frequency channels received by the reception unit, and which makes the hopping frequency decision unit perform frequency hopping, first by calculating packet error rates for each frequency channel on the basis of the number of the reception operations of the packet data and the number of the packet errors detected by the error detection unit, secondly by estimating channel qualities by using the packet error rates, thirdly by determining whether or not the received frequency channels are usable on the basis of a result of estimation of the channel qualities, and fourthly by avoiding the frequency channels determined to be unusable.

13. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 1;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

2. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which estimates channel qualities of the frequency channels received by the reception unit, and which makes the hopping frequency decision unit perform frequency hopping, first by calculating packet error rates of frequency channels of which the channel qualities are assumed to be good and used in reception operations of the packet data to estimate channel qualities, secondly by measuring field strengths in idle slots of frequency channels of which the channel qualities are assumed to be bad and not used in the reception operations of the packet data to estimate channel qualities, thirdly by determining whether the frequency channels are usable or not on the basis of an estimation result of channel qualities of frequency channels being estimation targets of the channel qualities, and fourthly by avoiding frequency channels determined to be unusable.

14. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 2;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

3. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by storing packet error indexes for each frequency channel when the reception unit receives the packet data, secondly by updating the packet error indexes from an equation of “

packet error index”

=packet error index retroactive by one×

{1−

(1/B)} when no errors are found in packets received by the reception operation, where B is a positive natural number and 1/B is a value ranging from 0 to 1, thirdly by updating the packet error indexes from an equation of “

packet error index”

=packet error index retroactive by one×

{1−

(1/B)+(1/B)} when errors are found in packets received by the reception operation, fourthly by estimating the channel qualities by using the updated packet error indexes as packet error rates, fifthly by determining whether the frequency channels are usable or not on the basis of an estimation result of channel qualities of frequency channels being estimation targets of the channel qualities, sixthly by determining whether the frequency channels can be used, from the estimated channel qualities, and seventhly by avoiding the frequency channels determined to be unusable.

15. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 3;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

4. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which estimates channel qualities of the frequency channels received by the reception unit, and which makes the hopping frequency decision unit perform frequency hopping, first by starting estimation of channel qualities on the basis of a calculation result of packet error rates after performing the packet reception operations by the number of predetermined times, secondly by calculating packet error rates for each packet reception operation after this to update the estimation of the channel qualities, thirdly by determining whether the frequency channels are usable or not on the basis of an estimation result of channel qualities of frequency channels being estimation targets of the channel qualities, and fourthly by avoiding frequency channels determined to be unusable.

16. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 4;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

5. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by individually evaluating quality performance on the basis of packet error rates and field strengths measured if the frequency channels are idle slots for each frequency channel selected by the hopping frequency decision unit when the reception unit receives the packet data, secondly by determining whether the frequency channels are usable or not on the basis of an estimation result of channel qualities of frequency channels being estimation targets of the channel qualities, thirdly by selecting whether channel qualities estimated from the packet error rates are used or channel qualities estimated from a measurement result of field strengths are used while taking a frequency of measurement slots into account at the time of measuring field strengths, fourthly by determining whether the frequency channels are usable or not on the basis of the selected channel qualities, and fifthly by avoiding frequency channels determined to be unusable.

17. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 5;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

6. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by associating a result of performance of sequential field effect strength measurements in idle slots with packet error rates which can be measured as a result of actual communications using each frequency channel, secondly by estimating channel qualities from a measurement result of field strengths for each selected frequency channel, thirdly by determining that the channel qualities are bad if the measured field strengths are higher than field strengths being prescribed packet error rates, fourthly by estimating that the channel qualities are good if the measured field strengths are lower than field strengths being prescribed packet error rates, fifthly by estimating whether the frequency channels are usable or not on the basis of a result of an estimation of the channel qualities, and sixthly by avoiding frequency channels determined to be unusable.

18. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 6;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

7. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping,

first by deciding frequency channels to be used in response to channel qualities estimated by a predetermined method when the reception unit receives the packet data, secondly by assuming that the channel qualities are packet error rates, thirdly by comparing the packet error rates of each frequency channel with one another, and fourthly by deciding frequency channels of predetermined number as channels to be used in descending order of channel qualities.

19. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 7;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

8. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by calculating packet error rates on the basis of error detection in packet reception operations to estimate channel qualities when the reception unit receives the packet data, secondly by deciding frequency channels to be used in response to the estimated channel qualities, and thirdly by starting reuse of frequency channels determined that channel qualities were deteriorated in past times not to be used when packet error rates of frequency channels used currently become more than predetermined values.

20. A radio communication terminal comprising:

a semiconductor integrated circuit device according to claim 8;

a radio antenna connected to the circuit device; and

a host connected to the circuit device to transmit and receive data and commands to and from the integrated circuit.

9. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising;

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by calculating packet error rates on the basis of error detection in packet reception operations when the reception unit receives the packet data to estimate channel qualities, secondly by deciding frequency channels to be used in response to the estimated channel qualities, and thirdly by starting reuse of frequency channels in ascending order of packet error rates at the time when frequency channels were not used from among frequency channels determined that channel qualities were deteriorated in past times and stopped to be used when packet error rates of frequency channels used currently become more than predetermined values.

10. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising;

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by calculating packet error rates on the basis of error detection in packet reception operations when the reception unit receives the packet data to estimate channel qualities, secondly by determining whether the frequency channels are usable or not on the basis of an estimation result of channel qualities of frequency channels being estimation targets of the channel qualities, thirdly by subtracting predetermined first values from the packet error rates if quality estimation results of each channel notified from other radio devices are good, fourthly by adding predetermined second values to the packet error rates quality estimation results of each channel notified if from other radio devices are bad, and fifthly by deciding frequency channels to be use in response to the calculating packet error rates.

11. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it;

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which controls the transmission unit, first by estimating packet error rates when the reception unit receives the packet data to determine frequency channels to be used, and secondly by transmitting radio waves power at a maximum defined in response to the number of frequency channels determined to be used if the number of frequency channels determined to be used is smaller than predetermined number.

12. A semiconductor integrated circuit device for a radio communication terminal of a frequency hopping system to transmit/receive a packet by sequentially using a plurality of frequency channels, comprising:

a hopping frequency decision unit which selects one frequency channel from among the plurality of frequency channels;

a transmission unit which assigns packet data to the selected frequency channel to transmit it,

a reception unit which receives the packet data of the selected frequency channel; and

a control unit which makes the hopping frequency decision unit perform frequency hopping, first by first estimating packet error rates when the reception unit receives the packet data to determine frequency channels to be used, secondly by using a number of channels defined by transmission power even if the number of frequency channels determined to be used is smaller than the number defined by transmission power at that time for performing transmission operations.