JPH06508973A - Method and circuit for selecting radio receiver tuning - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Background of the Invention: Method and Circuit for Selecting Radio Receiver Tuning TECHNICAL FIELD The present invention relates generally to wireless receivers, and more particularly, to frequency channel sets. A method of selecting radio receiver tuning to a certain frequency channel of and how to implement it.

A communication system operates to transmit information between two or more locations; It includes at least a transmitter and a receiver interconnected by a communication channel. wireless A communication system is one in which the communication channel consists of radio frequency channels. is a communication system in which a channel is defined by a range of frequencies in the communication spectrum. .

A transmitter that forms part of a wireless communication system transmits information over a radio frequency channel Contains circuitry to convert it into a format suitable for This type of circuit uses a process called modulation. It includes a modulation circuit that performs the processing. This process uses a radio frequency electromagnetic signal called a carrier signal. The information to be transmitted is superimposed on the waves. The signal obtained in this way is generally a modulated signal. It is called a number. The modulated signal contains the information exchanged between the transmitter and the receiver, so this Such signals are also called communication signals.

Various modulation methods are known to generate communication signals by superimposing information signals onto carrier signals. It is being For example, amplitude modulation.

Frequency modulation9 Phase modulation and their combinations superimpose information onto a carrier wave. This is a modulation method for generating communication signals.

wireless communication in that it does not require a physical interconnection between transmitter and receiver The system is advantageous. In other words, when an information signal is modulated and becomes a modulated signal, this modulated signals can be transmitted over long distances.

Furthermore, many modulated signals can be transmitted simultaneously at different frequencies in the electromagnetic frequency spectrum. can be done. A frequency defined on a particular frequency band of the electromagnetic frequency spectrum. Transmission of communication signals over frequency channels is regulated by regulatory agencies.

A two-way communication system is similar to the wireless communication system described above, but A wireless communication system that allows information to be transmitted and transmitted from a location. It is Tem.

Each location in such a two-way radio communication system includes both a transmitter and a receiver. be. A transmitter and receiver located in one location can also be used as a radio transceiver. Generally, it simply consists of a device called a transceiver.

A cellular communication system is a geographical area covered by a cellular communication system ( wireless transceiver placed at any location within a geographical area It is a type of two-way wireless communication system that allows communication over the internet.

A cellular communication system consists of multiple fixed station radio transceivers called base stations. formed by placing them at spaced locations throughout the target area. The base station is a traditional Connected to the wired telephone network. Each base station has a geographical area adjacent to each base station. Some are related. Such a part is called a cell. Each has multiple bases A plurality of cells defined by a station's corresponding base station constitutes a cellular communications system. 0 cellular communication system that defines the coverage area What is a wireless transceiver called a radiotelephone? , a base station located anywhere within the coverage area of a cellular communication system. can communicate with users of traditional wireline telephone networks through the network.

Communication signals generated by wireless telephones are sent to base stations, where they are connected to traditional wired telephones. The desired wired location is transmitted via the telephone network to enable telephone communications. Also electric When making a call using a wired device, you can also communicate with a wireless phone.

The traditional operating protocols of most cellular communication systems are Determines which base stations the radiotelephone transmits to and receives communication signals from . Transmitting communication signals from base station power to wireless telephones is called "communication down 1 non-k". Yes, it is the transmission of communication signals from a wireless telephone (called ``communication anoplink'').

Frequency channels (frequency allocated for cellular communications) into which the frequency channels are divided are: It is further divided into a control channel and a traffic channel. traditional cellular communications In the system, control channels and traffic channels are separated as different frequencies. defined. In systems employing time division multiplexing methods, control channels and Rahic channels are defined to be channels of similar frequency, but at different times. Defined as a slot.

A control channel is assigned by a base station for the transmission of communication signals called control signals. It will be done. The radiotelephone transmits control signals (when the radiotelephone is powered on and periodically during operation). It operates to scan. The power level of the signal transmitted on the control channel is known. , in response to this measurement, the radiotelephone generates a control signal on one of its control channels. Attempt to understand the information content. In such a signal transmission stage, the selected The information content of the control signal transmitted on the control channel can be grasped, and this control The information content of the control signal transmitted on the channel satisfies predetermined conditions. A communication downlink is performed if the The radiotelephone receiving circuit uses this selected Tuning to the control channel is maintained. In effect, the radio telephone has selected control Tune into a channel and "listen" to the information being transmitted on it. This radio phone This action is sometimes called "camping" in wireless telephones. When a communication downlink is established between the base station and the radiotelephone, the radiotelephone It is sometimes referred to as "camping at a base station (cell station)."

Once the communication downlink is established between the radiotelephone and the base station, the radiotelephone reception circuit is The path can be powered down and then powered back up again periodically at the desired cycle. Wear. During the period when the receiver circuit is repowered, the selected control channel (i.e. Control signal information transmitted on a control channel (on which a radiotelephone is “camped”) The content of the information will be monitored.

(However, control signals are sometimes carried on the traffic channel. , such restrictions are implemented after a communication link has already been established between the radiotelephone and the base station. Generally, a control signal is sent. ) Since the receiver circuit is powered on only periodically, the communication downlink with the base station is Once established, the energy consumption of such a circuit is minimized.

When a call is made to a radiotelephone, the information content of the control signal is transmitted through the radiotelephone. communication is initiated therein to a specific channel of the network channel.

With the proliferation of cellular communication systems, many such cellular communication systems have May be operated at capacity. i.e. frequencies allocated for cellular communications All available traffic channels of a node may be utilized.

In order to connect even more users of such cellular communication systems, A method has been developed to make more effective use of frequency bands allocated for various purposes. do.

In particular, cellular communication systems that use more efficient modulation schemes to increase capacity stem has been introduced. discretely-encode d) Modulation methods that utilize information signals are based on frequency channels allocated for cellular communications. more efficiently. Therefore, it is necessary to adopt such a modulation method. This allows more users to utilize the cellular communication system simultaneously.

This type of modulation method utilizes the time division multiplexing method briefly mentioned above to transmit data. Generate easy-to-use communication signals.

Traditional and high-capacity cellular communication systems are generally not compatible. do not have. That is, wireless telephones that operate in traditional cellular communication systems use high-capacity cells. It does not work with La communication systems. (A dual-mode radiotelephone can be used with any cellular Although it also works in communication systems, such dual-mode radio telephones have dual circuits. one circuit section operates in one system and the other circuit section operates in the other system. system and is rotated depending on the communication system by which the radiotelephone is operated. Either one of the road sections becomes operational. ) two or more communication systems May be located in a geographical area. For example, traditional cellular communication systems and high-capacity cellular communication systems that provide cellular service on either system. located in a specific geographical area serving Traditional cellular communications in different geographic areas Only the system is installed. (Similarly, geographic regions where only high-capacity systems are installed There are also areas. ) In still other geographical areas, cellular communication systems are not installed. Not yet.

As previously mentioned, when the radiotelephone's receiver circuit is powered on, the radiotelephone is activated by a control channel. channel to detect the presence of a control signal transmitted on this channel. wireless radio If the phone is located in a geographic area without cellular service, the control channel However, no signal transmitted by the base station is detected.

Also, cellular communication systems (i.e., traditional cellular communication systems or high-capacity A wireless telephone made to work with one specific cellular communications system (in another) have cellular service provided by incoherent cellular communication systems Once placed in a location, the radiotelephone is connected to the cellular communications system in which it operates. The presence of control signals transmitted on a defined control channel cannot be detected.

The frequency bands of traditional cellular communication systems and high capacity cellular communication systems are Operates in frequency bands with overlapping frequencies, so the radiotelephone has no control channel Detects the presence of control signals transmitted by the other party's cellular communication system when searching for Sometimes it comes out. But these systems are inconsistent, so like this The information content of the detected signal cannot be determined by this radiotelephone.

Many wireless telephones are made to operate on battery power. battery power Due to limited energy storage capacity, such wireless telephones can only be used for a limited time. (not working).

The radiotelephone searches for control signals by looking for control signals transmitted on the control channel. The wireless telephone must be energized. The radiotelephone relies on the presence of a signal on the control channel. In addition to searching, you can also check the information content of detected signals.

Wireless telephones may be used in locations without cellular service or with inconsistent cellular communication systems. When placed in a location with cellular service, the wireless phone searches for a control channel. This will deplete the stored energy in the battery power supply that powers the radiotelephone. Ru. Therefore, by continuing to search in this way, you can save money by searching for control channels. The amount of stored energy is consumed, which limits the operating period during which the radiotelephone can communicate. It turns out.

Therefore, if the communication link with the base station cannot be established, the wireless telephone will use the control channel. Measures are needed to limit continued searching.

Summary of the invention Accordingly, the present invention provides a method and its associated circuitry that overcomes the limitations of the prior art. That's true.

Furthermore, the present invention provides that when a communication link cannot be established with the base station, the wireless telephone Provides a means to limit continued searching for channels.

The invention includes further advantages and features, details of which are given below in the details of the preferred embodiments. This will become clear after reading the explanation.

According to the invention, one of the frequency channel sets defined on a frequency band is A method for selecting the tuning of a radio receiver's tuning circuit for the frequency channel to be used and this method. Related circuitry for implementing this is disclosed. Frequency channel cent each frequency channel A communication signal transmitted by a transmitter in a group of remotely located transmitters. suitable for transmission. The tuning circuit of a radio receiver is tuned to a frequency defined on a frequency band. It is tuned to each frequency channel of the wave number channel and seven nodes. Frequency channel sensor The power level of the communication signal transmitted on the individual frequency channels of the target is measured.

A frequency channel whose measured power level is greater than or equal to a predetermined minimum power level is selected. , a first subset of frequency channels. radio receiver and this frequency channel an individual transmission of a transmitter transmitting a communication signal on a first subcent frequency channel of A determination is made whether a communication link can be established with the device. with wireless receiver for a given frequency channel transmitted by a transmitter over which a communication link can be established. The tuning of the radio receiver's tuning circuit should be selected when such a communication link is possible. It will be done.

Brief description of the drawing A further understanding of the invention can be obtained by reading it in conjunction with the accompanying drawings. Let's come.

FIG. 1 illustrates a cellular communication system in which the method and circuit of the preferred embodiment of the present invention operates. FIG. 2 is a partial schematic block diagram of the system.

Figure 2-1 is a schematic diagram of a portion of frequency bands allocated for cellular communications. Ru.

Figure 2-2 shows the frequency channels defined on one frequency channel employed in the time division multiplexing method. FIG. 2 is a schematic diagram of one frequency channel showing the time slots to be used;

FIG. 3 is a logical block diagram of a wireless receiver including circuitry of a preferred embodiment of the present invention. Ru.

Figure 4-1 shows the power levels of control signals measured during operation of a preferred embodiment of the present invention. and the dynamically set noise floor derived from it. It is a diagram of the relationship between

Figure 4-2 shows the power levels of the control signals measured during operation of the preferred embodiment of the present invention. FIG.

Figure 5 shows the power level of the previously measured signal and the power level of this signal when measured again. This figure shows the relationship between the used during operation of the preferred embodiment.

FIG. 6 is a logical flow diagram of an algorithm embodying the method of the preferred embodiment of the present invention. It is.

FIG. 7 is a logic flow diagram illustrating the method steps of a preferred embodiment of the present invention.

FIG. 8 is a block diagram of a wireless transceiver including circuitry of a preferred embodiment of the present invention. be.

DESCRIPTION OF THE PREFERRED EMBODIMENT First, in the schematic diagram of FIG. 1, a cellular communication system designated by the reference number 100 is show. As previously mentioned, cellular communication systems are distributed across geographical areas. formed by placing a large number of base stations in a location. Such a base station is In Figure 1, points 104, 108, 112° 116, 120, 122, 12 6,130. Although eight base stations are shown in the figure, cellular The typical cellular communication system represented by communication system 100 is much more versatile. Of course, it is composed of many base stations.

Each base station 10 if the wireless telephone is located at a location within range of the respective base station. 4 to 130 are capable of transmitting communication signals transmitted by this base station to multiple wireless telephones. and can receive communication signals transmitted by a plurality of such radiotelephones.

Each base station 104-130 is coupled to a conventional wireline telephone network. In the diagram , such a connection is a line interconnecting the base station 130 and the wireline network 138. 134. Between wired line network 138 and other base stations 104 to 126 The connections can be shown similarly.

The placement of each base station 104 to 130 making up the cellular communication system 100 is carefully selected. a geographical area that is selected and has at least one base station covered by system 100; Receive communication signals sent by radiotelephones located anywhere within the area and thereby define the cellular service area of the system.

That is, at least one base station 104-130 may be located at any location in a geographical area. must be within the transmission range of the radiotelephone located at the site.

(The maximum signal strength of the signal transmitted by the base station and the maximum transmission range are greater than the maximum signal strength and corresponding maximum transmission range of the signal generated by the Generally large, the maximum transmission range of the signals generated by a radiotelephone is This is the main factor to consider when locating base stations for communication systems. ) Due to the nature of the base stations being located apart, the geographical location of the base stations 104 to 130 may vary. Parts of the area are associated with individual base stations. At each spaced apart base station 104-130 Portions of adjacent geographical areas define "cells" and these cells are designated area 1 in the diagram. Represented by 44,148,152,156,160,162.166.170 It will be done. Cells 144-170 together form a geographic area and include cellular communication system 10. Define the service area covered by 0. Any cell in system 100 144-170 are located within the boundaries of at least one base station 10. It is possible to transmit and receive modulated signals to and from 4 to 130.

Communication system 100 may be a conventional cellular communication system or a high capacity cellular communication system. Represents tem.

Also, as mentioned above, the general protocol for communication operations in cellular communication systems In this case, various base stations are connected on various control channels defined in the communication system. The radiotelephone detects a communication signal called a control signal transmitted by the radiotelephone. cellular communication system Each base station in the system communicates with such base station on a predetermined control channel. transmits a control signal to identify the presence of a wireless phone on a selected control channel If you check the information content of the control signal sent above, the communication downlink with the wireless phone will be established. Do the following. (Again, if a time division multiplexing method is adopted, the control channel traffic channels are on similar frequencies but in different time slots. determined. ) When a communication downlink is established between the radiotelephone and the base station, the radiotelephone reception circuit is The road section is powered down and then powered back up at the desired duty cycle. This periodic You can check it at intervals.

When placing a call to a wireless telephone, the information content (i.e. data) of the control signal is Tune a radiotelephone to a specific traffic channel defined on a communications system to enable two-way communication between the radiotelephone and the base station.

Otherwise, the receiver portion of the radiotelephone is set to the desired duty cycle. Power down based on

However, when a wireless telephone is placed outside the coverage area of a cellular communication system, Searching for the control channel of a communication system does not detect a signal that can establish a communication link. I can't. For example, the radiotelephone represented in the figure as radiotelephone 174 is a cellular communication Located outside the cellular service area of system 100. Cellular Sir If the wireless telephone searches for a control channel, the system Establishing a communication link with signals transmitted by base stations 104-130 of lOO I can't. control signals of communication systems to detect the presence of transmitted signals, and Continuing to search for the information content of a detected signal is time and energy consuming.

Wireless telephones are often powered by battery power, so To maximize the operating life of a battery-powered radiotelephone, the energy consumption of the radiotelephone is It is desirable to limit costs.

Also, as mentioned above, with the advent of high-capacity cellular communication systems, two or more The cellular service area of the self-communication system above is geographically and frequency-wise. May overlap. In Figure 1, points 204 and 208 are #2 cellular communication system. Cells 214 and 218 in the dotted line represent the base stations of the second cellular communication system. represents the service area of the cell. The shaded area 222 represents the two cellular communication systems. Represents geographic overlap in service areas. The wireless telephone located in area 222 is by both the base station 122 of the system 100 and the base station 208 of the second communication system. Can detect transmitted control signals. Control of the cellular communication system in which radio telephones operate control signals generated by the base station of the other communication system when searching for a control channel. signals may be detected by the radiotelephone. These two communication systems are aligned communication downlink with the base station of the other cellular communication system is established. Can not. Therefore, the detected control signal on such a control channel is is ignored.

In addition, the communication system in which the radiotelephone operates in the first place (here, for illustrative purposes located outside the cellular service area of the cellular communication system 100). was located within the service area of this cellular communications system. , the radiotelephone becomes the control channel of the communication system when placed within this service area. It must be possible to detect the presence of control signals transmitted on the However, this system Continuously searching the control channel of a communication system to detect the presence of a control signal is extremely difficult. energy consumption.

Figure 2-1 is designated by the reference number 300, assigned for cellular communications. A schematic diagram of frequency bands is shown.

The frequency band 300 is divided into multiple frequency channels, some of which are ．． A control channel, denoted as , ,D, and a traffic channel, V, , V2. V8. ．． ．． .

V. It is. Typical operation of establishing a communication link with a base station when powering up a radiotelephone Based on the protocol, the radiotelephone operates on each control channel defined on the frequency band 300. Find a channel.

FIG. 2-2 shows one frequency channel represented by reference numeral 306 and one frequency channel represented by reference number 306. 2 is a schematic diagram of time slots defined on this channel in time periods; FIG. Zhou The wave number channel 306 is one frequency channel when a time division multiplexing method is adopted. represents a time slot defined on a network. Frequency channel 306 Define the number of time slots. Using the symbols in Figure 2-1, time slots V1~ ■1 is defined as the traffic channel, and the other time slots D1 to D are restricted. It is defined as a control channel.

The method and circuit of the preferred embodiment of the invention may be conventionally defined or time-dependent. Since it is possible to search for the control channel defined in the multiplexed system, The figures and Figures 2-2 use similar symbols.

The tuning circuit of the reception section of such a radiotelephone is configured to tune the radiotelephone to each control channel D, . D2. Control transmitted on any control channel in tune with , , , D Detect the presence of a signal.

The power level of the control signal detected on any control channel is measured (such as The maximum power level of the detected signal (by checking the information content of the detected signal) A communications link is attempted with the transmitter that transmits the .

Such transmitters and A communication downlink can be established.

This means establishing a communication downlink with a base station in an incoherent cellular communication system. The information content of such control signals can be verified by radiotelephone. do not have. attempt to establish a communications link with one of the base stations of a cellular communications system In some cases, such data signals are subsequently used by the radiotelephone when searching for a control channel. is ignored.

The power level of the signal detected by the receiving circuitry is quickly and efficiently (i.e. Encoding that can be claimed without consuming much energy, but is detected by the receiver Determining the information content of a signal generally requires the operation of a signal processing circuit. . Such circuits require relatively large amounts of energy to operate. Main departure The goal is to minimize the amount of time such processing circuits must operate. It is advantageous to be able to do this.

Next, in the logical block diagram of FIG. 1 shows a circuit of a preferred embodiment of the present invention constructed by elements surrounded by blocks; . The circuit 400 shown in FIG. constitute the department. Wireless receiver 406 may be, for example, a wireless receiver operating in a cellular communication system. It may also constitute a receiving circuit section of a wireless transceiver such as a line telephone.

The radio receiver 406 receives control channels D1 to D shown in FIG. 2-1 or 2-2. , looking for predetermined control channels like , , individual control channels detecting the presence of a control signal transmitted on the

The control channel indicated by line 412 is transmitted by a transmitter, such as transmitter 416. and detected by antenna 418 of receiver 406. By antenna 418 A signal representative of the detected signal is generated on line 420 and is /downconvert circuit 422.

Circuit 422 responds to a signal provided on line 436 to first control the control channel. Tune the receiver to a particular frequency channel.

Circuit 422 identifies the frequency channel to which circuit 422 tunes receiver 406. A signal is generated on line 448 representing a control signal in the frequency channel of . line The signal generated on 448 is applied to demodulator 458 and signal strength measurement circuit 468. available. Demodulator 458 produces a demodulated signal on line 464, which is coder 470. Decoder 470 generates a signal on line 476; This signal is provided to processing unit 482. Decoder 470 further includes line 48 6, and this signal is sent to a transducer 488, such as a speaker. be combined.

Signal strength measurement circuit 468 generates a signal on line 492, which signal is transmitted to the processing device. 482 and the power level of the signal produced on line 448. The information provided to the processor 482 is provided to the processing device 482. The signal generated on line 448 is connected to the antenna represents the signal detected by 418, so the signal generated on line 492 Level similarly represents the power level of the signal detected by antenna 418.

In the figure, memory device 496 is connected to processing unit 482 by line 498. is shown.

In operation, the wireless receiver 406 first receives a predetermined Find each channel of the control channel of the control signal sent on that channel. Detect presence.

Processor 482 generates a signal on line 436 to connect circuit 4 to each control channel. 22 in sequence. When receiver 406 tunes to each control channel, each A signal representative of the signal detected on the control channel of Generated on 8. Signal strength measurement circuit 468 measures the signal generated on line 448. and generates a signal on line 492 representing this power level. process Device 482 stores such measured values in memory device 496 . Processing device 4 82 identifies the measured power level and the frequency channel over which such signal was transmitted. Correlate.

Once the power levels of the data signals transmitted on the various control channels are measured , the processor 482 communicates with a transmitter for transmitting control signals on one of the control channels. determine whether an attempt should be made to establish a link.

To make such a determination, processor 482 determines which of the control channel cents A first subset of control channels is generated. These constitute the first subset. control channel in response to the power level of the control signal transmitted on that channel. selected.

In a preferred embodiment, the data signal has 1) a dynamically set "noise floor"; or 2) have a power level greater than either the absolute value noise floor. Only those control channels are selected to constitute the first subset of control channels.

The dynamically set noise floor is measured by signal strength measurement circuit 468. It is set by comparing the power level of each control signal. noise floor is set at a power level of a certain value greater than or equal to the smallest measured power level. It will be done.

Figure 4-1 shows the dynamically configured FIG. Each arrow 560 is controlled by receiver 406 of FIG. Represents a signal detected on a channel. The height of each arrow 560 indicates its power level. represent. Line 550 depicting the dynamically set noise floor indicates the lowest power level. The specified power level, represented by bracket 570, is greater than or equal to the power level of the signal at This lowest power level signal is indicated by arrow 560 on the far right of this diagram. Therefore, it is expressed as frequency channels on the data signal with power levels above this noise floor. A channel is selected to form the control channel of the first subcent. Dynamically set The determined noise floor value depends on the measured power level value, so set it in this way. The value of the noise floor determined varies depending on the actually measured value of the control signal.

The absolute value noise floor is the power level of a selected magnitude. No. 4-2 The diagram is a diagram of the absolute value noise floor represented by line 605. Each arrow 61 0 represents the signal detected on the control channel. The belief represented by arrow 610 The number corresponds to the signal represented by arrow 560 in Figure 4-1, and the height of each arrow is represents its power level.

A frequency channel is selected whose control signal power level is greater than this noise floor. , forming a first subset of control channels.

As described above, in the preferred embodiment, the control signal transmitted on the control channel is dynamic. or the absolute value noise floor set to Control channels are selected to form a first subset of control channels.

Attempts to establish a communication link with the transmitter to transmit control signals to the receiver 406 This is done only with transmitters transmitting signals on one subset of control channels.

The useful information of the control signal demodulated by demodulator 458 and provided on line 465 is A communication link is established only if decoder 470 indicates the presence of information. (vinegar In other words, the information content of the control signal transmitted on the selected control channel can be confirmed. Decoder 470 generates a signal on line 476 if ) line 476 The signal generated by decoder 470 above and provided to the input of processing unit 482 shows proper decoding of the information content of such control signals, thereby Indicates that a communication link can be established with a transmitter that sends control signals.

Sending a control signal on the frequency channels of such first subset of frequency channels. If a communication link cannot be established with a transmitter that is transmitting data, the radio receiver will It stops and starts trying again to establish a downlink with the transmitter. this time period During this period, portions of the receiver's circuitry are powered down, and during this period the receiver 406 limit energy consumption.

(For example, decoder 470, which typically comprises a digital signal processor, You can power down to ) In the preferred embodiment, the receiver portion is powered down. The time period to This is the shorter of the two intervening periods.

TP=(X+(y*number of frequency channels of first subset))ne2% however, TP is the time period (in seconds); X to measure the power level of the data signal transmitted on any control channel y is the time period required for the decision to make an attempt to establish a communication link with one of the base stations; time required to tune the receiver 406 to a particular control channel ;and Z is the desired duty cycle of the radio receiver.

After a period of time during which the receiver is powered down, all circuitry in receiver 406 Power is reapplied to the device and circuit 422 is again operative to control each of the frequency bands. Tune the receiver to the channel. Each signal sent on its respective control channel is again measured (i.e., remeasured) by circuit 468; A signal representative of such measured power level is provided on line 492 to processing unit 482. available. Processor 482 is configured to process control signals transmitted on respective control channels. and the remeasured power level of the first supplant. ・The last measured signal transmitted on the frequency channel of the throat frequency channel Compare with the power level.

Processor 482 forms a second subset of control channels. The data signal is 1) Previously, the noise floor was smaller than the one set for Dynamis Tsuku, but the remeasurement At regular times the power level is greater than this dynamically set noise floor. 2) The previous measurement was smaller than the absolute value noise floor, but when re-measuring, this have a power level greater than the absolute noise floor, or 3) significant power of a control channel indicating an increase in level (e.g., a 6 dB power level increase) are selected to form the channels of the second subset of control channels. and, Communication links are established only with transmitters that transmit signals on this second subset of frequency channels. An attempt is made to establish a At this time as well, the decoder 470 operates and the communication link is established. A signal is generated on line 476 to indicate whether the signal can be set.

(Note that other methods of selecting frequency channels for the second subset are also available. I want to be For example, instead of steps 1) and 2) above, last time we was smaller than both the noise floor and the absolute noise floor set on the A data signal that has a power level greater than the noise level of either side at a fixed time. control channels can be used to form a second subset of control channels. )tsu Therefore, processing unit 482 processes signals that were previously below both noise floors, i.e. Signals below the dynamically set noise floor or below the absolute noise floor and the signal is higher than the respective noise floor or significantly louder when remeasured. Determine which frequency channel the signal is on.

In the figure, line 499 is for resetting receiver operation at any time. is shown as an external input line to the processing unit 482. This kind of belief For example, by activating an activation switch connected to line 499. can be generated.

Figure 5 shows which frequency channels to form the second subset of frequency channels. FIG. 4 is a diagram of the operation of processing device 482 to determine whether to select a file. Here too, like this communication links only with transmitters that transmit signals on a second subset of control channels. An attempt is made to establish a

Horizontal line 650 represents a dynamically set noise floor; 55 represents the absolute value noise floor.

(The relative value of the noise floor can also be inverted, i.e. the absolute value noise floor can be dynamically The value may be greater than the noise floor set for the ) arrow 606 indicates miscellaneous Frequency channels with initial measured power levels less than the sound floor 650.655 Represents a signal sent over a channel. (Noise floor 650.655 is shown in Figure 4-1 and Note that they correspond to noise floors 550 and 605 in Figure 4-2, respectively. . ) The power level of the signal 606 during the initial measurement is lower than the noise floor, so it is not reliable. The frequency channel on which the signal 606 is transmitted is part of the frequency channel of the first subcent. It is not.

However, if the receiver stalls for a period of time determined by the aforementioned algorithm, After the power level of the signals transmitted on each control channel is remeasured, Signals generated on the same control channel, represented by arrow 644, point The signal indicated by the line is higher than at least one of the noise floors. Such control Channels are selected to form a second subset of frequency channels. Ma and transmitting a control signal on the selected control channel of the second subset of control channels. An attempt is made to establish a communications downlink with the transmitter that is communicating. Significantly more power A control channel with a control signal that has a level (remeasurement value is above the noise floor) ) to form the control channel of the second subset. selected. Such a signal is represented by arrow 670 in FIG. has been done.

The power levels of the data signals transmitted on each control channel were remeasured. Later, if a communication downlink cannot be established, the wireless receiver 406 It pauses again for a while, and the receiver circuitry powers down again. In a preferred embodiment, the location The fixed time period corresponds to the larger of the fixed time period or the algorithm described above. is the time period.

That is, the time period during which portions of the receiver are powered down is a fixed amount of time (e.g., 1 5 seconds) and the time period given by:

TP-(x+ (y*number of frequency channels of the first subset)) TP is the time period (in seconds); X to measure the power level of the data signal transmitted on any control channel The time period required for; y to attempt to establish a communication link with one of the base stations. Once the decision has been made, it is necessary to tune the receiver 406 to a particular control channel. time; and 2 is the desired duty cycle of the radio receiver.

Returning to Figure 1, if the wireless telephone is outside the cellular service area of the cellular communication system lOO signals transmitted by different base stations on the control channel (interfering with noise) The sound is below the floor. A radiotelephone with built-in circuitry similar to radio receiver 406 can Establish a communication downlink with a base station that transmits such a signal on a wavenumber channel If the wireless telephone device is not connected to the cellular communication system 100, within the cell service area and on each IIJ channel. Once the power level of the data signal transmitted by the base station is remeasured, the control signal At least one of the The power level is significantly higher than that of 1. Such data signal power τ transmitted iL 1lI Ij control channel is selected and becomes the control channel of the second subset of frequency channels. communication with a base station that transmits such a signal on one of these control channels. An attempt is made to establish a communication link. Send control signals on each control channel radio reception for a predetermined period after it is determined that a communication link with the transmitter cannot be established. Since the transmitter circuitry is powered down, the energy consumption of the radio equipment is minimized. Ru.

This way of selecting control channels to form a second subset of control channels. This process is repeated, attempting to establish a communication downlink, and The receiver circuit powers down if link cannot be established. For example, for 10 minutes, If the communication downlink cannot be established after the selected time period, the system will try again. is activated and re-establishes the control channels of the first subset.

Referring now to the logic flow diagram of FIG. 6, employing the method of the preferred embodiment of the present invention, An algorithm represented by reference number 680 is shown. First, in block 684 The power level of the signal transmitted on each control channel is measured as shown . As shown in block 688, a first subset of control channels is formed and A transmitter that sends a control signal on one such channel, as shown in lock 692, An attempt is made to establish a communications downlink with the transmitter.

At decision block 696, it is determined whether a communications downlink can be established. Ru. If the downlink can be established, take the YES branch to block 700 and The tuned frequency of the receiver tuning circuit is maintained at the frequency of the selected control channel. So Otherwise, take the No branch and read the measured power level as shown in block 704. signal is stored and the receiver portion is powered off for a period of time as shown in block 708. -Down.

Once this time period has elapsed, the receiver portion is powered on again and enters block 708. The power level of the control signal transmitted on the control channel is remeasured as shown.

A second subset of control channels is formed as shown in block 712, and a second subset of control channels is formed as shown in block 712. a transmitter that transmits a control signal on one such channel as shown in block 716; An attempt is made to establish a downlink.

At decision block 720, it is determined whether a communications downlink can be established. Ru. If the downlink can be established, take the YES branch to block 724 and accept The tuned frequency of the receiver tuning circuit is maintained at the frequency of the selected control channel. So Otherwise, take the No branch and read the measured power level as shown in block 728. The bell is saved and updates the saved power level, as shown in block 732. The receiver portion is powered down for a period of time.

Once this period of time has elapsed, the power level of the control signal is increased, as shown in block 736. It is determined whether the extra time has passed since the first measurement (block 684). . If the extension time has expired, the YES branch continues to block 684 for processing. is repeated. Otherwise, take the No branch to block 710; The power level of the control signal is remeasured.

In the logic flow diagram of FIG. 3 illustrates the steps of a preferred embodiment method;

Method 750 includes determining one of a set of frequency channels defined on a frequency band. Select the tuning of the radio receiver's tuning circuit for one frequency channel. frequency chi Each frequency channel in a channel set is a transmitter for a group of remotely located transmitters. suitable for transmitting communication signals transmitted by machines.

First, as indicated by block 756, the tuning circuit of the radio receiver is Tune to each frequency channel of a set of frequency channels defined on a frequency band be done.

Next, as shown in block 762, each frequency channel of the frequency channel set is The power level of the communication signal transmitted over the cable is measured.

Next, as shown in block 768, on the frequency channel over which the communication signal is transmitted, the measured power level is greater than the lowest power level and the frequency of the first subset Frequency channels forming a channel are selected.

Next, as shown in block 774, the wireless receiver and the first subset of frequency channels are connected to each other. communication between each transmitter that sends a communication signal on the frequency channel of the channel. It is determined whether a link can be established.

Next, as shown in blocks 778 and 782, a communication link with the wireless receiver is established. For the frequency channel of a communication signal transmitted by a transmitter that can be established The tuning of the receiver tuning circuit is selected, or 1) the tuning circuit of the radio receiver is 2) the power of the communication signal. The level is remeasured, 3) a second subset of frequency channels is formed, and 4) the communication frequency channel of the second subset of frequency channels if a communication link can be established. The tuning of the radio receiver's tuning circuit to the channel is selected.

Finally, in the block diagram of FIG. 8, reference is made to so.

1 shows a wireless transceiver, such as a wireless telephone represented by .

Transceiver 800 includes circuitry 806, which is a preferred embodiment of the invention. It is composed of elements within the block indicated by the dotted line. Circuit 806 is the circuit of FIG. This corresponds to road 400. The receiving section of the wireless transceiver 800 is shown in the block diagram of FIG. The radio receiver shown in FIG. wireless tran Looking at the receiving section of the receiver 800, the wireless transceiver 800 includes an antenna 818. line 820 is connected to this antenna, making antenna 818 programmable. It can be seen that it is interconnected to tuning/downconversion circuit 822. circuit 82 The operation of 2 is controlled by an input signal provided on line 836. circuit 8 22 produces a signal on line 848, which is connected to demodulation circuit 858 and signal strength measurement. is coupled to constant circuit 868 . Demodulation circuit 858 produces a demodulated signal on line 864. and this is provided to decoder 870.

Decoder 870 produces a signal on line 876, which is an input to processing unit 882. is combined with Decoder 870 also generates a decoded signal on line 886, which This is provided to a transducer 888, such as a speaker. Signal strength measurement circuit 8 68 generates a signal that is provided to processing unit 882 via line 892. It will be done. Memory element 896 is further coupled to processing unit 882 via line 898. Line 899 provides external input to processing unit 882 .

Wireless transceiver 800 is further shown including a transmitter, which transmitter Transducer 9o8. Encoder 912, modulator 916 and and programmable tuning/upconversion circuitry 922.

The operation of circuit 922 is controlled by an input signal provided via line 928. It will be done. Circuit 922 generates a signal on line 934, which is coupled to antenna 818. combined to enable the transmission of information signals.

Although the present invention has been described above with reference to various drawings and preferred embodiments, other Similar embodiments of the invention may also be utilized and perform the same functions of the invention without departing from the invention. It will be understood that modifications and additions may be made to the embodiments described. Therefore , the invention is not limited to a single embodiment, but is to be construed in accordance with the scope of the appended claims. Should.

Figure 2-1 Figure 2-2 111111 @ L Upper Shoulder Figure 4-1 Figure 5 Flute 7 diagram μda Continuation of front page (72) Inventor: Rape, Duane See, Rollin, Illinois, USA Gu Meadows, Millstone 2702 (72) Inventor: Pinzel, Charles Pea Hoffma, Illinois, USA N Estin, 665 Darian Court (72) Inventor: Arora, Arvwind Nis, Illinois, USA - Linton Heights, 1207 South Old Wilk

Claims (10)

[Claims] 1. for a set of frequency channels defined on a frequency band. A circuit for selecting a tuning frequency of a tuning circuit of a radio receiver, the circuit selecting the tuning frequency of a tuning circuit of a radio receiver, Each frequency channel in a channel set is assigned to a transmitter in a group of remotely located transmitters. The circuits suitable for transmitting communication signals are: The tuning circuit of the radio receiver is tuned to a frequency channel defined on the frequency band. means for tuning each frequency channel of the set; a communication signal transmitted on each frequency channel of said set of frequency channels; means for measuring the power level of the signal and storing the value of the measured power level; Frequency channels of communication signals whose measured power level is greater than a predetermined minimum power level means for selecting a frequency channel to form a first subset of frequency channels; the wireless receiver and a frequency channel of the selected first subset of frequency channels; A communication link can be established with each of the transmitters that send communication signals on the channel. a means of determining when to when it is determined by said means for determining that a communication link can be established; The frequency of the communication signal transmitted by the transmitter with which the communication link of the radio receiver can be established. A method for selecting the frequency tuning of the tuning circuit of the radio receiver with respect to the wave number channel. Dan; A circuit characterized by comprising: 2. Said means for tuning comprises a set of frequency channels defined on a frequency band. means for sequentially tuning the radio receiver to each of the frequency channels. 2. The circuit of claim 1, characterized in that: 3. Said means for measuring power levels comprises communication signals on respective frequency channels. A circuit according to claim 1, characterized in that it comprises means for measuring the amplitude of a signal representing . 4. The measured power level measured by the measuring means is a memory element. A circuit according to claim 1, characterized in that the circuit is stored in a. 5. Select frequency channels that form a selected subset of frequency channels. said minimum power level used by said means for selecting a predetermined 2. The circuit of claim 1, wherein the circuit comprises an absolute minimum power level. 6. Select frequency channels that form a selected subset of frequency channels. the minimum power level used by the selecting means to characterized in that the level is related to the measured power level measured by a 2. The circuit according to claim 1, wherein: 7. The minimum power level is the measured power level that has the smallest value among the measured power levels. A claim characterized in that the value corresponds to a predetermined level greater than the power level. The circuit according to item 6. 8. Said means for determining when a communication link can be established comprises: Decode the communication signal transmitted on the frequency channel of the frequency channel to generate the decoded signal means for generating a portion of the decoded signal and the wireless receiver in response to the decoded signal; and a means for comparing data stored in the transmitter. 2. The circuit according to claim 1. 9. a tuning circuit of the radio receiver for each frequency channel of the set of frequency channels; means for retuning; on each frequency channel of said set of frequency channels; A means of re-measuring the power level of communication signals transmitted by; high power above a certain level Select the frequency channel of the communication signal that indicates the level, and means for forming a set of frequency channels of the second subset; A communication link is established between each transmitter that sends communication signals over a frequency channel. means for determining whether a communication link can be established; and if a communication link can be established; Select radio receiver tuning to frequency channels for a subset of frequency channels. 2. The circuit according to claim 1, further comprising means for selecting. 10. before retuning the power level after being determined by said determining means; further comprising means for delaying operation of the recording means for a predetermined period of time; 10. The circuit according to claim 9, characterized in that: