Method and system for quickly finding a control channel in a private cellular system
AssigneeNorthern Telecom Limited
InventorChenhong Huang
Life of this patent
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Abstract
The method of quickly locating non-standard control channels in private cellular systems is accomplished in an embodiment of the present invention by determining the modulation type of a particular channel. The mobile station scans a received RF channel. The received signal is used for the evaluation of the modulation type of that channel by using matched filters designed for the specific signal of interest, and/or in another embodiment of the present invention is used for producing the spectral energy distribution of the channel revealing the type of modulation.
Claims8
In a radio communication system utilizing a plurality of channels, a method for identifying one of the channels as a control channel including the steps of:
- accepting an input signal from one of said channels;
- comparing said input signal to a predetermined baseline signal by passing said input signal through a matched filter configured to identify a predetermined characteristic of the input signal;
- identifying the input signal as a control channel based on a predetermined characteristic of the comparison results;
- wherein the radio communication system is a mobile radiotelephone system and the plurality of channels is divided into a plurality of voice/data channels and a plurality of control channels.
A method of identifying and selecting a control channel from a plurality of voice/data channels within a cellular network including a base station and a mobile unit, the method comprising the steps of:
- accepting an input signal from one of said channels;
- comparing said input signal to a predetermined baseline signal by passing the signal to a plurality of matched filters, each filter optimized to identify a modulation type of the input signal as one of the group of FM, FSK and QPSK modulation types;
- identifying the input signal as a control channel based on said modulation type;
- selecting a channel identified as containing a control signal for initiating and controlling communication with a base station;
- and
- storing the channel number in memory.
A mobile unit for use in a wireless telephone system comprising:
- means for receiving an input signal;
- means for comparing said input signal to a predetermined baseline signal;
- means for generating a comparison result including matched filter means operably connected to the input signal for identifying a predetermined characteristic of the input signal based on the comparison of the baseline and input signal;
- means for identifying the input signal as a control channel based on a predetermined characteristic of the comparison result;
- and
- means for selecting the identified control channel identified for initiating and controlling communication with a base station.
Dependencies are inferred from the claim text.