Power amplifier share in wireless communication system with transmitting diversity

Abstract

The technique of amplifier sharing is implemented in a system designed to accommodate transmit diversity. In one embodiment of the invention, the amplifiers (670 and 675) are shared 1) to amplify a first and a second diversity-encoded signal, each of which represents the information of a first signal that is to be transmitted using transmit diversity, and 2) to amplify a second signal to be transmitted without using transmit diversity. The first and second diversity-encoded signals are used to form a first and a second composite signal. Each composite signal is amplified in a different one of two power amplifiers (670 and 675). Each amplified composite signal is then used to form an amplified first diversity-encoded signal and an amplified second diversity-encoded signal. The first and second composite signals can also be formed using the second signal. Each composite signal is then amplified in a different one of the two power amplifiers (670 and 675) and the two amplified composite signals are used to form an amplified second signal. In another embodiment of the invention, the first and second composite signals can be formed in the digital domain. Each composite signal is digitally pre-distorted and then modulated onto a transmission frequency signal, such as an RF signal. Each pre-distorted composite signal is then amplified in the respective amplifier (670 and 675).

Description

Technical field: [0001] The present invention relates to efficient use of amplifier power capacity, eg in wireless communication systems with transmit diversity. Background technique: [0002] In wireless communication systems, a geographical area is divided into a plurality of spatially distinct areas called "cells". Each cell contains a base station, which includes equipment for communicating with a Mobile Switching Center (MSC). The MSC is connected to local and / or long-distance transport networks, such as the Public Switched Telephone Network (PSTN). Each base station also includes radio equipment, a power amplifier and an antenna, which the base station uses to communicate with mobile terminals, each communication session with a particular mobile terminal being called a "call". [0003] As the mobile terminal moves, the signal strength received at the mobile terminal from the base station changes. This variation is due to various factors including the distance of the...

AI Technical Summary

Problems solved by technology

If the second power amplifier is of the same capacity as the first power amplifier, the first power amplifier may not be underutilized, however, the second power amplifier has a relatively large power capacity at this time, and when all mobile terminals are not When diversity is enabled, all this power capacity is wasted

(Note that in this case even when some mobile terminals are diversity-capable and some mobile terminals are not-diversity-capable, a considerable amount of power capacity of the power amplifier is wasted) Because, the cost of the power amplifier is proportional to its power capacity, and since the power amplifiers used in these types of applications are very expensive (typically 15% to 25% of the total cost of the base station), the wasted power capacity in the above two cases can be considerable cost of

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