Multi-carrier receiver with dynamic power adjustment and method for dynamically adjusting the power consumption of a multi-carrier receiver

Abstract

A method for dynamically adjusting the power consumption of a multi-carrier receiver and a multi-carrier receiver with dynamically power adjustment. The method includes receiving a multi-carrier signal, wherein the multi-carrier signal comprises a plurality of sub-carriers. Channel characteristics of each sub-carrier are estimated according to the demodulated multi-carrier signal. ICI strength is estimated from the demodulated multi-carrier signal. A system performance is detected. The estimated ICI is subtracted when the ICI strength exceeds an ICI threshold and the system performance is less than a system performance threshold. The demodulated multi-carrier signal is then equalized is based on the estimated channel characteristics, and the system performance is updated according to the equalized multi-carrier signal.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application is a Continuation of application Ser. No. 12 / 185,232, filed on Aug. 4, 2008, the entirety of which is incorporated by reference herein.BACKGROUND OF THE INVENTION[0002]The invention relates to receiving multi-carrier signals, and, more particularly, to receiving multi-carrier signals with dynamic power adjustment.[0003]Multi-carrier modulation methods, such as orthogonal frequency division multiplexing (OFDM), have been around for some time now. OFDM is a modulation method designed in the 1970's in which multiple symbols are transmitted in parallel using different sub-carriers. An OFDM system forms its symbol by taking k complex QAM symbols Xk, each modulating a sub-carrier with frequencyfk=kTu,where Tu is the sub-carrier symbol period. Each OFDM sub-carrier displays asinc(x)=sin(x)xspectrum in the frequency domain. By spacing each of the 2N+1 sub-carriers1Tuapart in the frequency domain, the primary peak of each sub-carr...

AI Technical Summary

Benefits of technology

[0002]The invention relates to receiving multi-carrier signals, and, more particularly, to receiving multi-carrier signals with dynamic power adjustment.

Problems solved by technology

Mobile reception, however, remains one of the problems associated with OFDM systems.

A moving receiver would experience Doppler shifts, which corrupt the orthogonality among each sub-carrier, and decrease the system performance.

In such a case, inter-carrier interference (ICI) occurs because signal components from one sub-carrier cause interference with other, mostly neighboring, sub-carriers.

Time-varying channels also limit the system performance.

Although ICI cancellation and MPE-FEC can improve system performance, these two features consume relatively more power.

Since handheld devices have limited battery power, system designers must compromise between system performance and power consumption.

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