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1. (WO1991000655) RECEIVER WITH VARIABLE PREDETECTION BANDWIDTH BASED ON EXPECTED DATA RATE
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Claims

1. A selective call receiver, comprising:
means for receiving a modulated data signal having a variable bit rate and including a code indicative of the bit rate;
a demodulator;
a bandpass filter for filtering the signal prior to demodulation in the demodulator, said bandpass filter having an adjustable bandwidth; and
means for adjusting the bandwidth of the bandpass filter in response to the code received.

2. The receiver of claim 1, wherein said means for adjusting the filter bandwidth are arranged to change the bandwidth a predetermined first time after receipt of the code.

3. The receiver of claim 2, wherein said means are arranged to increase the bandwidth at said first time from a narrower to a wider bandwidth.

. The receiver of claim 3 wherein means are provided for switching the receiver from a lower to a higher bit rate receive mode at substantially the same time as said first time.

5. The receiver of claim 4 wherein means are provided for returning the receiver to said lower bit rate receive mode at a predetermined second time after said first time and for restoring the filter bandwidth from said wider to said narrower bandwidth at substantially the same time as said second time .

6. The receiver of claim 1 wherein said filter is arranged to provide a bandwidth selectable to correspond to at least two different bandwidths .

7. The receiver of claim 1, wherein said adjustable bandwidth filter comprises at least two discrete filters and switching means for directing the signal through a selected one thereof.

8. The receiver of claim 8 wherein the discrete filters are ceramic filters .

9. A selective call system, comprising:
a transmitter for transmitting a modulated data signal, said transmitter including means for selecting a bit rate for the signal, and means for including a code in said signal indicating the bit rate determined;
a selective call receiver for receiving the signal including the code, said receiver having a demodulator and a bandpass filter for filtering the signal prior to demodulation in the demodulator, said bandpass filter having an adjustable bandwidth; said receiver also having means for adjusting the bandwidth of the bandpass filter in response to the code received.

10. A method of operation of a selective call system, comprising the steps of:
transmitting a modulated data signal at a bit rate selected from a plurality of bit rates, said signal including a code indicating the bit rate;
receiving the signal at a selective call receiver having a demodulator and a bandpass filter for filtering the signal prior to demodulation in the demodulator, said bandpass filter having an adjustable bandwidth; and
adjusting the bandwidth of the bandpass filter in response to the code received.