Method and apparatus for maximizing the use of available capacity in a communication system

• US 7,720,022 B2
• Filed: 02/08/2001
• Issued: 05/18/2010
• Est. Priority Date: 03/08/1999
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Lundby, Stein A.
• Primary Examiner(s): Ly; Anh-Vu H
• Assistant Examiner(s): Nguyen; Toan D
• Application Number:
  US09/779,719
• Publication Number:
  US 20010008520A1
• Time in Patent Office: 3,386 Days
• Field of Search: 370/320, 370/335, 370/342, 370/254, 370/328, 370/329, 375/130, 455/522, 455/13.4, 455/21, 455/69
• US Class Current: 370/328
• CPC Class Codes: H04B 7/2631 for broadband transmission
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

A method and apparatus for maximizing the use of available capacity in a communication system having a base station and a plurality of mobile stations. The forward link includes a plurality of traffic streams sent on at least one channel from the base station to the mobile stations. The forward link is subject to a maximum power ceiling. A first output power level associated with simultaneously transmitting a first set of one or more traffic streams on the forward link is initially determined. Next, the first output power level is compared to the maximum power ceiling; and at least one time frame in the forward link having available capacity for transmitting a portion of at least one further traffic stream is identified. The first set of traffic streams and the portion of the at least one further traffic stream are then transmitted simultaneously during the at least one frame on the forward link.

Claims

1. In a radio communication system having a base station and a plurality of mobile stations, a method for transmitting traffic information from the base station to a mobile station, comprising the steps of:

(A) intentionally transmitting the traffic information from the base station with a first symbol energy amount that is intentionally insufficient for correct demodulation of the traffic information by the mobile station;

(B) after step (A), retransmitting from the base station the traffic information initially transmitted with the first symbol energy amount, wherein the traffic information is retransmitted in step (B) with a further symbol energy amount that is also insufficient by itself for correct demodulation of the traffic information by the mobile station; and

(C) repeating step (B) until a sum determined at the mobile station of the first and further symbol energy amounts used to transmit the traffic information is great enough to permit correct demodulation by the mobile station.

2. The method of claim 1, wherein the further symbol energy amount used for re-transmitting the traffic information in step (B) is determined at the base station using fast forward power control.

3. The method of claim 1, further comprising the steps of:

(D) determining, at the mobile station, a received energy value corresponding to the traffic information transmitted from the base station in step (A); and

(E) transmitting the received energy value from the mobile station to the base station;

(F) wherein the further symbol energy amount used for re-transmitting the traffic information in step (B) is determined at the base station in accordance with the received energy value transmitted from the mobile station.

4. The method of claim 3, wherein the received energy value is transmitted from the mobile station to the base station using an acknowledgement protocol.

5. The method of claim 4, wherein the acknowledgement protocol is transmitted between the base station and the mobile station using forward and reverse control channels.

6. The method of claim 5, wherein the traffic information is transmitted in steps (A) and (B) on a supplemental channel, and the forward and reverse control channels have a lower error rate than the supplemental channel.

7. The method of claim 3, wherein the received energy value is transmitted from the mobile station to the base station using a negative acknowledgement protocol.

8. The method of claim 7, wherein an acknowledgement protocol is transmitted between the base station and the mobile station using forward and reverse control channels.

9. The method of claim 8, wherein the traffic information is transmitted in steps (A) and (B) on a supplemental channel, and the forward and reverse control channels have a lower error rate than the supplemental channel.

10. The method of claim 1, further comprising the step of:

(D) summing the traffic information transmitted with the first symbol energy amount in step (A) with the traffic information transmitted with the further symbol energy amount in step (B) by combining received energy associated with the traffic information transmitted with the first symbol energy amount in step (A) with received energy associated with the traffic information transmitted with the further symbol energy amount in step (B) in a buffer at the mobile station; and

(E) demodulating the traffic information at the mobile station in accordance with the result of step (D).

11. In a mobile radio telephone system having a base station controller that services a plurality of base station transceivers that transmit traffic information to a plurality of mobile stations, an apparatus for transmitting traffic information from a base station transceiver to a mobile station, comprising:

(A) a power allocation unit at the base station controller that selects a first symbol energy amount for transmitting the traffic information from the base station transceiver to the mobile station, wherein the power allocation unit allocates power among a number of different streams of the traffic information such that none of the streams are initially transmitted with enough power for correct demodulation by the mobile station, and the power allocation unit selects a further symbol energy amount for retransmitting the traffic information from the base station transceiver to the mobile station, wherein the further symbol energy amount is also insufficient by itself for correct demodulation of the traffic information by the mobile station;

(B) a base station transmitter that initially transmits the traffic information from the base station transceiver to the mobile station at the first symbol energy amount and subsequently retransmits the traffic information from the base station transceiver to the mobile station at the further symbol energy amount; and

(C) a buffer in the mobile station that combines the retransmitted traffic information from each of the streams of the traffic information until a sum determined at the mobile station of the first and further symbol energy amounts used to transmit the traffic information is great enough to permit correct demodulation of the streams by the mobile station.

12. In a mobile radio telephone system having a base station that transmits traffic information to a plurality of mobile stations, an apparatus for transmitting traffic information from the base station to the mobile station, comprising:

(A) a power allocation unit at the base station that selects a first symbol energy amount for transmitting the traffic information from the base station to the mobile station, wherein the first symbol energy amount is insufficient for correct demodulation of the traffic information by the mobile station, and the power allocation unit selects a further symbol energy amount for retransmitting the traffic information from the base station to the mobile station, wherein the further symbol energy amount is also insufficient by itself for correct demodulation of the traffic information by the mobile station;

(B) a base station transmitter that initially transmits the traffic information from the base station to the mobile station at the first symbol energy amount and subsequently retransmits the traffic information from the base station to the mobile station at the further symbol energy amount; and

(C) a buffer in the mobile station that combines retransmitted the traffic information until a sum determined at the mobile station of the first and further symbol energy amounts used to transmit the traffic information is great enough to permit correct demodulation.

13. In a mobile radio telephone system having a base station and a plurality of mobile stations, an apparatus for transmitting traffic information from the base station to a mobile station, comprising:

(A) means for intentionally transmitting the traffic information from the base station with a first symbol energy amount that is insufficient for correct demodulation of the traffic information by the mobile station;

(B) means for re-transmitting from the base station the traffic information initially transmitted with the first symbol energy amount, wherein the traffic information is retransmitted with a further symbol energy amount that is also insufficient by itself for correct demodulation of the traffic information by the mobile station; and

(C) means for repeating step (B) until a sum determined at the mobile station of the first and further symbol energy amounts used to transmit the traffic information is great enough to permit correct demodulation by the mobile station.