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Error estimation based proportion power control method in CDMA (Code Division Multiple Access) cellular system

A power control algorithm and error estimation technology, which is applied in the field of communication and can solve the problems of occupied channel capacity, poor real-time performance of the algorithm, and cumbersome implementation process.

Inactive Publication Date: 2012-07-11
SHANDONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] Although the above power control algorithm is given in the case of random and time-varying link gain, the power control loop is only analyzed from the perspective of a single user, and the implementation process is cumbersome, requiring additional complex prediction and estimation algorithms. The performance is not good, and accurate feedback information is required, which occupies the channel capacity

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  • Error estimation based proportion power control method in CDMA (Code Division Multiple Access) cellular system
  • Error estimation based proportion power control method in CDMA (Code Division Multiple Access) cellular system
  • Error estimation based proportion power control method in CDMA (Code Division Multiple Access) cellular system

Examples

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example 1

[0112] Example 1. Considering a single-cell CDMA system, some simulation results of the proportional power control algorithm (ProPC) based on the sigmoid function are given. The omni-directional base station is located in the center of the cell, there are Q, (Q=10) active mobile users, and the users are evenly distributed in the cell and share the same channel. The spread spectrum bandwidth is 1.2288MHz, and the user data transmission rate is 9.6kbps (spread spectrum gain is equal to 21dB). The link gain from user i to the base station includes path fading and shadow fading, defined as:

[0113] g i = s i d i - β - - - ( 4.1 )

[0114] d i is the distance from the i-th user to the base station; β is the path fading index, where β=4; sha...

example 2

[0118] Example 2: Considering a multi-cell DS-CDMA cellular communication system, some simulation results of the error estimation-based proportional power control algorithm (EProPC) and its improved algorithm (MEProPC algorithm) are given. system( Figure 6 There are 19 sub-districts in total in the shown), the omni-directional base station is located in the center of the sub-district, there are Q, (Q=190) activated mobile users are evenly distributed in the system, the spread spectrum bandwidth is 1.2288MHz, and the user data transmission rate is 9.6kbps ( The spreading gain is equal to 21dB). The propagation link power attenuation is modeled as including large-scale path fading, shadow fading and Rayleigh fading. The path fading is related to the distance from the user to the base station, and the path fading index is β=4; the shadow fading factor si obeys the logarithmic normal distribution [E(s i )=0dB,σ(s i )=8dB]; Rayleigh fading is produced according to the jakes mod...

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Abstract

The invention discloses an error estimation based proportion power control method in a CDMA cellular system, which comprises the following steps of: dialing by a mobile subscriber, transmitting signals to a base station; after the base station receives the signals, calculating a deference value of a target signal to interference ratio and a signal to interference ratio of the mobile subscriber according to different types, and transmitting the symbol of the difference value back to the mobile subscriber; after the mobile subscriber receives the symbol which is transmitted back, estimating theerror of the signal to-interference ratio by using an estimation algorithm; substituting the error of the signal to interference ratio in a proportion power control algorithm to obtain a new proportion power control algorithm; and calculating a new signal transmission power of next time by the mobile subscriber according to the new proportion power control algolithm. The invention can be applied to a real CDMA cellular communication system. In an up-link, the mobile subscriber estimates the error of the signal interference ratio according to a 1-bit or 2-bit signalling transmitted back by thebase station; and the invention can be applied to a self-adaption variable-step power control algorithm for adjusting transmission power.

Description

technical field [0001] The invention relates to a proportional power control method based on error estimation in a CDMA cellular system, which is suitable for the communication field. Background technique [0002] The CDMA system is a self-interference system, and the capacity is affected by the interference level of the system itself. Effectively controlling the transmission power can well overcome the near-far effect and multiple access interference, thereby improving the system capacity. In addition, power is a limited resource of the communication system. How to reduce the transmit power of the transmitter as much as possible while satisfying the QoS conditions of more users is the core issue of power control. In recent ten years, the power control problem has aroused people's widespread attention, and researchers have solved the power control problem from different angles. With the advent of the 3G era, CDMA technology has been widely used in real life. Therefore, an ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H04W52/24H04W52/36
Inventor 曹叶文刘倩
Owner SHANDONG UNIV