Capacity enhancement for multi-code CDMA with integrated services through quality of services and admission control

• US 6,278,701 B1
• Filed: 07/10/1998
• Issued: 08/21/2001
• Est. Priority Date: 07/10/1998
• Status: Expired due to Fees

• Current Assignee: University of Maryland, Verizon Laboratories Incorporated (Verizon Communications Inc.)
• Original Assignee: University of Maryland, Verizon Laboratories Incorporated (Verizon Communications Inc.)
• Inventors: Ayyagari, Deepak, Ephremides, Anthony, Resheff, Samuel
• Primary Examiner(s): Olms, Douglas
• Assistant Examiner(s): Pizarro, Ricardo M.
• Application Number:
  US09/113,551
• Time in Patent Office: 1,138 Days
• Field of Search: 370/335, 370/336, 370/341, 370/342, 370/431, 370/441, 370/468, 370/320, 370/318, 370/310, 455/522, 455/446, 455/403, 455/422, 455/517, 455/69, 455/88
• US Class Current: 370/335
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 7/264 for data rate control
• CPC Class Codes: H04J 13/0077 Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04W 52/265 taking into account the quality of service QoS
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/283 Power depending on the position of the mobile
• CPC Class Codes: H04W 52/286 during data packet transmission, e.g. high speed packet access [HSPA]
• CPC Class Codes: H04W 52/288 taking into account the usage mode, e.g. hands-free, data transmission, telephone
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading

Abstract

With the addition of high-speed data traffic to traditional CDMA cellular networks, there is a need to efficiently utilize system capacity so that the quality of service of existing voice and low-speed data users is maintained while new high-speed data users are added to the network. Methods and systems are presented that control allocation of power to users, quality of service requirements, and/or user activity levels to enhance capacity utilization. These methods and systems are based on a method for estimating the capacity of a CDMA carrier with both voice and data users using an interference-based analysis of the reverse link. In particular, the methods enhance capacity utilization in a multi-code CDMA network architecture, in which several codes are allocated to a single high-speed data user for parallel transmission.

Claims

1. A method for enhancing the capacity of a CDMA cellular carrier supporting traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each user having an adjustable received power level, and the plurality of voice users having a fixed quality of service requirement, the method comprising the steps of:

setting a quality of service requirement for the plurality of data users based on the traffic from the plurality of users and the voice user quality of service requirement;

adjusting the received power level of each of the plurality of voice users so that their received power levels are identical;

adjusting the received power level of each of the plurality of data users so that their received power levels are identical to the received power levels of the plurality of voice users;

decreasing the received power level of each of the plurality of data users until their quality of service requirement is satisfied; and

adjusting the quality of service requirement for the plurality of data users in response to a request from a new data user to access the cellular carrier.

2. A method for enhancing the capacity of a CDMA cellular carrier supporting traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each data user having an adjustable activity factor and capable of transmitting at an adjustable activity lcvel, and each user having a fixed quality of service requirement, the method comprising the steps of:

determining a measure of the traffic from the plurality of voice users;

determining a measure of the traffic from the plurality of data users;

assigning to each of the data users an identical number of codes;

adjusting the activity factor for each data user based on the measures of traffic from the plurality of voice users and the plurality of data users and the quality of service requirement of each of the plurality of users; and

controlling the activity level of each of the plurality of data users in response to the adjusted activity factor.

3. The method of claim 2 wherein the controlling step includes the substep of transmitting a message to each of the plurality of data users indicating a percentage of time during which each data user may transmit.

4. The method of claim 2 wherein the controlling step includes the substep of continuously transmitting an indicator to each of the plurality of data users, a value of the indicator indicating that the data user has permission to transmit, wherein the indicator is set to the value randomly based on the adjusted activity factor.

5. The method of claim 2 further comprising the step of reducing the number of codes assigned to each of the plurality of data users in response to a request from a new data user to access the cellular carrier.

10. The method of claim 2, wherein the step of adjusting the activity factor is performed by a base station;

and wherein the step of controlling the activity level is performed by each of the plurality of data users.

6. A method for enhancing the capacity of a CDMA cellular carrier supporting traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each data user having an adjustable received power level, and each user having a quality of service requirement, the method complising the steps of:

assigning a feasible power level to each of the plurality of users;

determining a minimum power level to each of the plurality of users;

determining a maximum received power level from among the received power levels of the plurality of users;

determining a ratio of the maximum received power level to the minimum power level determined for each of the plurality of users;

selecting smallest ratio from the determined ratios;

scaling the minimum power level determined for each of the plurality of users by the smallest ratio; and

assigning the scaled power level to each of the plurality of users.

7. A computer-readable medium containing instructions for enhancing the capacity of a CDMA cellular carrier supporting traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each user having an adjustable received power level, and the plurality of voice users having a fixed quality of service requirement, by:

setting a quality of service requirement for the plurality of data users based on the traffic from the plurality of users and the voice user quality of service requirement;

adjusting the received power level of each of the plurality of voice users so that their received power levels are identical;

adjusting the received power level of each of the plurality of data users so that their received power levels are identical to the received power levels of the plurality of voice users;

decreasing the received power level of each of the plurality of data users until their quality of service requirement is satisfied; and

adjusting the quality of service requirement for the plurality of data users in response to a request from a new data user to access the cellular carrier.

8. A computer-readable medium containing instructions for enhancing the capacity of a CDMA cellular carrier supporting traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each data user having an adjustable activity factor and capable of transmitting at an adjustable activity level, and each user having a fixed quality of service requirement, by:

determining a measure of the traffic from the plurality of voice users;

determining a measure of the traffic from the plurality of data users;

assigning to each of the data users an identical number of codes;

adjusting the activity factor for each data user based on the measures of traffic from the plurality of voice users and the plurality of data users and the quality of service requirement of each of the plurality of users; and

controlling the activity level of each of the plurality of data users in response to the adjusted activity factor.

9. A computer-readable medium containing instructions for enhancing the capacity of a CDMA cellular carrier supporiing traffic from a plurality of users, including a plurality of voice users and a plurality of multi-code data users, each data user having an adjustable received power level, and each user having a quality of service requirement, by:

assigning a feasible power level to each of the plurality of users;

determining a minimum power level for each of the plurality of users;

determining a maximum received power level from among the received power levels of the plurality of users;

determining a ratio of the maximum received power level to the minimum power level determined for each of the plurality of users;

selecting a smallest ratio from the determined ratios;

scaling the minimum power level determined for each of the plurality of users by the smallest ratio; and

assigning the scaled power level to each of the plurality of users.