Communication apparatus and transmit power control method

• US 20010019962A1
• Filed: 02/21/2001
• Published: 09/06/2001
• Est. Priority Date: 03/02/2000
• Status: Abandoned Application

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Goto, Masahiko
• Application Number:
  US09/788,570
• Publication Number:
  US 20010019962A1
• Time in Patent Office: Days
• US Class Current: 455/522
• 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

Abstract

When the SIR of the received signal is larger than the SIR upper limit, threshold determining section 105 outputs an instruction for decreasing the transmit power to control bit generating section 106. Further, when the SIR is smaller than the SIR lower limit, threshold determining section 105 outputs an instruction for increasing the transmit power to control bit generating section 106. When the SIR of the received signal is equal to or smaller than the SIR upper limit and equal to or larger than the SIR lower limit, threshold determining section 105 outputs the determined result to control bit generating section 106. When the SIR of the received signal is equal to or smaller than the SIR upper limit and equal to or larger than the SIR lower limit, control bit generating section 106 refers to a last instruction on the transmit power control stored in storage section 107, and outputs an instruction opposite to the last instruction with respect to an increase or decrease in the transmit power to storage section 107 and multiplexing section 108.

Claims

1. A radio communication apparatus comprising:

measuring means for measuring a received quality of a signal transmitted from a communication partner;

instructing means for performing an instruction for changing transmit power to said communication partner from a result obtained by comparing the received quality of the signal with a required received quality;

storage means for storing the instruction for changing transmit power; and

transmitting means for transmitting the instruction for changing transmit power to said communication partner,

wherein said instructing means provides a value of the required received quality with a range allowing a change in the transmit power caused by a propagation delay of a transmit power control signal to perform the instruction for changing the transmit power.

2. The radio communication apparatus according to

claim 1

, wherein said instructing means performs the instruction for decreasing the transmit power to said communication partner when the received quality of the signal is higher than an upper limit of a predetermined range, further performs the instruction for increasing the transmit power to said communication partner when the received quality of the signal is lower than a lower limit of the predetermined range, and refers to a previous instruction for changing the transmit power stored in said storage means to perform the instruction for changing the transmit power so as to maintain the received quality of the signal in the predetermined range when the received quality of the signal is in the predetermined range.

3. The radio communication apparatus according to

claim 2

, wherein said instructing means refers to the previous instruction for changing the transmit power stored in said storage means when the received quality of the signal is in the predetermined range, and when a last instruction for changing transmit power is indicative of increasing the transmit power, generates the instruction for decreasing the transmit power, while when the last instruction for changing transmit power is indicative of decreasing the transmit power, generating the instruction for increasing the transmit power.

4. The radio communication apparatus according to

claim 3

, further comprising:

setting means for setting the predetermined range with a predetermined variation range from the required received quality.

5. The radio communication apparatus according to

claim 1

, wherein said instructing means changes the range into an arbitrary range at an arbitrary timing.

6. The radio communication apparatus according to

claim 1

, wherein when the required received quality is changed, said instructing means performs the instruction for decreasing the transmit power when the received quality of the signal is higher than the required received quality, while performing the instruction for increasing the transmit power when the received quality of the signal is lower than the required received quality, not depending on whether the received quality of the signal is in the range during one or a plurality of measuring periods immediately after changing the received quality.

7. A mobile station apparatus having a radio communication apparatus, said radio communication apparatus comprising:

measuring means for measuring a received quality of a signal transmitted from a communication partner;

instructing means for generating an instruction for changing transmit power to said communication partner from a result obtained by comparing the received quality of the signal with a required received quality;

storage means for storing the instruction for changing transmit power; and

transmitting means for transmitting the instruction for changing transmit power to said communication partner,

wherein said instructing means performs the instruction for decreasing the transmit power to said communication partner when the received quality of the signal is higher than an upper limit of a predetermined range, further performs the instruction for increasing the transmit power to said communication partner when the received quality of the signal is lower than a lower limit of the predetermined range, and refers to a previous instruction for changing the transmit power stored in said storage means to perform the instruction for changing the transmit power so as to maintain the received quality of the signal in the predetermined range when the received quality of the signal is in the predetermined range.

8. A base station apparatus having a radio communication apparatus, said radio communication apparatus comprising:

measuring means for measuring a received quality of a signal transmitted from a communication partner;

instructing means for generating an instruction for changing transmit power to said communication partner from a result obtained by comparing the received quality of the signal with a required received quality;

storage means for storing the instruction for changing transmit power; and

transmitting means for transmitting the instruction for changing transmit power to said communication partner,

wherein said instructing means performs the instruction for decreasing the transmit power to said communication partner when the received quality of the signal is higher than an upper limit of a predetermined range, further performs the instruction for increasing the transmit power to said communication partner when the received quality of the signal is lower than a lower limit of the predetermined range, and refers to a previous instruction for changing the transmit power stored in said storage means to perform the instruction for changing the transmit power so as to maintain the received quality of the signal in the predetermined range when the received quality of the signal is in the predetermined range.

9. A transmit power control method, comprising:

measuring a received quality of a signal transmitted from a communication partner;

comparing the received quality of the signal with a required received quality, and based on the compared result, performing an instruction for changing transmit power to said communication partner

storing the instruction for changing transmit power; and

transmitting the instruction for decreasing the transmit power to said communication partner when the received quality of the signal is higher than an upper limit of a predetermined range, further transmitting the instruction for increasing the transmit power to said communication partner when the received quality of the signal is lower than a lower limit of the predetermined range, and referring to a stored previous instruction for changing the transmit power to transmit the instruction for changing the transmit power such that the received quality of the signal is maintained in the predetermined range to said communication partner when the received quality of the signal is in the predetermined range.