DE102008053359A1 - Automatic-gain-control-system supporting method for maximum-ratio-combining receiver, involves switching off receiving path by high-frequency portion of baseband chip, when receiving quality of path falls below preset reference value - Google Patents

Abstract

The method involves switching off a receiving path by a high-frequency portion of a baseband chip using an idle pattern, when receiving quality falls below a preset reference value of the receiving path. The idle pattern is transmitted between the high-frequency portion and a baseband processing portion. A radio signal strength indicator (RSSI) is temporarily switched off in the high-frequency portion, when the receiving quality falls below the reference value. A non-existent portion of a path is recognized based on the idle pattern.

Description

The The invention relates to a method for supporting an automatic gain control system (AGC system) according to the generic term the only claim.

The Application of Maximum Ratio Combining (MRC) for receivers with multiple receive paths require an equal gain setting at all reception paths, independent of the signal present at the individual reception path. In other words lies in the AGC unit for all receive paths have the same gain factor.

Of the Term receive path refers to a) at several receiving antennas either to a single antenna receive path, that is, one single receive antenna is equal to a single receive path, or b) at a single receiving antenna and at least two receiving paths, which are received only with a receiving antenna and which are separated in time or in frequency.

The Problem, which occurs here, is that at significantly different Receive signals per receive path (case a) with different strong reception signals per antenna) the amplification factor per reception path must be kept constant on all receiving paths so that the poorly received reception path compared to a well received signal not disproportionately reinforced which would lead to noise amplification in an MRC process.

in the Case that only one receive path a significant signal contribution and the other receive path does not, all are at an MRC receiver Receiving paths evaluated and thus consume unnecessary resources in the form of computing power and power.

task The present invention is based on a method of the type mentioned at the outset to technically improve this in the manner that in the case that only one receive path is a significant signal contribution and the other receive path is not, with an MRC receiver none unnecessary Resources in the form of computing power and electricity are consumed.

These The object is achieved by a Solved the procedure, that indicated in the characterizing part of the single claim Having method step.

After that A receive path is switched off if the reception quality of this Receive paths falls below a predetermined threshold.

It becomes dependent a function of signal strength in individual reception path, for example, depending on the English Language: radio signal strength indicator (RSSI) when falling below a predetermined threshold, the receive path in the high-frequency part temporary switched off and in English: idle pattern to the in english: Pass baseband. On the basis of the idle pattern, the baseband can not be present Recognize the contribution of the path and take it into account accordingly.

Of the special advantage is that the properties of one in English Language: Maximum Ratio Combiners are exploited in both normal operation can, this means, if the signal components on different receiving paths are not are significantly different, as well as exploited in a company can be in which the received signals are significantly different, because then using a threshold function, a receive path, that is a Receive antenna and a high-frequency reception path, and the corresponding Further processing in English: Baseband chip for power consumption reduction is turned off.

at turned off reception path is from the high-frequency part to the baseband chip by means of a transmitted between high-frequency part and baseband processing part Idle pattern signals the switching off of at least one receive path respectively controlled.

These Threshold function includes in particular the case that the useful signal subject to a high channel attenuation per received signal and the associated additive Noise or thermal noise is very high, so that for the disconnected receiving path a very poor signal-to-noise ratio (English Signal-to-noise ratio, SNR for short) in relation to the well-received Receive signal results.

Claims (1)

Method for supporting an automatic gain control system in a receiver having at least two receive antennas associated with a respective receive path , characterized in that a receive path is switched off when the receive quality falls below a predetermined threshold value.