FR2806580A1 - Combined mobile telephone and satellite positioning device has common quartz for both telephone and positioning circuits - Google Patents

Abstract

The combined mobile telephone and satellite positioning system (100) has a global positioning system (101) and secondary telephone circuits (102). The circuits have a common processor (111) for signal treatment from the circuits. The positioning system signals are executed following a frequency given by the correlator signal (19). The circuits share a common quartz which can operate at thirteen megahertz

Description

Mobile device comprising location means and mobile telephone means, and method of cooperation between these means The invention relates to a mobile device comprising location means and mobile telephone means, and a method of cooperation between these means. The invention particularly concerns two fields, namely the field of mobile telephony, and the field of mobile location devices. Indeed, the invention brings together in the same device functionalities which are found in these two fields. The object of the invention is to integrate these functionalities in a single device. This integration must be carried out by minimizing on the one hand the energy consumption of such a device, so that it has a maximum autonomy on the other hand by having minimum production costs. Another object of the invention is also to obtain a device whose dimensions do not exceed those of current mobile telephones. That is to say that the device according to the invention must have dimensions which allow it to be easily stored in a handbag or in a pocket.

In the state of the art, mobile phones are known which integrate a large number of functionalities. Among these functionalities one can cite functionalities of voice communication, data transmission, messaging, as well as multiple operating options. For a mobile phone operating according to the GSM standard, it is also possible to obtain a location of the mobile phone. This location is obtained by triangularization from two or more base stations. When a mobile telephone, operating according to the GSM standard, and connected to a base station, this base station supplies the mobile telephone with a so-called time advance parameter. This parameter is a synchronization parameter between the base station and the mobile phone. This parameter is the time advance with which the telephone must transmit in order for the base station to receive its transmission on the correct date. This parameter is directly related to the distance between the base station and the mobile phone. However, this parameter is quantified, that is to say that it has a certain spatial granularity. From a base station and a time advance we can therefore draw a crown of width 500 meters around this base station. From the intersection of several crowns we can therefore determine a position for the mobile phone. However we see that this method does not allow to locate with certainty the mobile phone. Indeed there remains in the location an uncertainty of more or less 125 meters. This precision remains largely insufficient for the applications envisaged, such as guiding a user of the mobile telephone. Indeed if the user is in a city and wishes to know which street he must take to get to a given place, its location 125 meters near is not sufficient.

In the state of the art portable location devices are also known. These devices are generally used by hikers or sailors. These devices provide a location in the form of latitude and longitude and most of them work with the GPS (Global Positioning Satellite) system. This system has real-time constraints and requires significant computing power in terms of microprocessor resources.

In the state of the art there are so-called electronic cards which deliver signals corresponding to a location. An obvious solution for obtaining a device having localization and mobile telephony functionalities would therefore be to integrate one of these so-called localization cards into a mobile telephone. We would thus obtain a device having the desired functionalities but consuming a lot of energy. This excessive consumption would therefore lead to a decrease in its autonomy, and would make it useless because it cannot be used far from an important energy source. In addition, the location map having a given size, there would be an increase in the size of the device thus obtained compared to a standard mobile phone. This increase in size would lead to a loss of ergonomics of the device.

An obvious solution to obtain sufficient autonomy is then to increase the size of the battery. In this case the size of the device increases correspondingly, both in volume and in weight. The device resulting from this solution therefore becomes a nuisance during transport and more difficult to use.

The invention solves these problems by using the same calculation resource, a signal processing processor, to carry out the processing on radio location signals and radio signals in mobile telephony. Thus GPS signals are received by the first antenna, digitized, correlated, then processed by the signal processing processor. Likewise, mobile phone signals are received by a second antenna, digitized, and then processed by the same signal processing processor. This constitutes a significant gain in integration and consumption. For the same reason, there is also only one crystal to produce the clock signals necessary for the activity of the localization and mobile telephone circuits. The base frequency of this quartz then multiplied by different factors in order to obtain frequencies useful for the activity of these circuits.

The signal processor cannot perform the localization and mobile telephony tasks at the same time, which is why there is a sequencing of these tasks. In this sequencing the mobile telephony tasks will have a higher priority. Indeed it would be penalizing for a user of a mobile phone not to receive, not to transmit, voice information. This would create an impression of communication interruption which is not admissible.

The subject of the invention is therefore a mobile device comprising first circuits dedicated to a satellite navigation activity producing digital signals for locating the device, second circuits dedicated to a mobile telephone activity producing digital voice signals, or message characterized in that the first and second circuits once combined comprise only one signal processing processor.

The subject of the invention is also a method of cooperation between localization tasks and mobile telephone tasks, characterized in that - part of the localization tasks are carried out using electronic localization circuits, - part of the tasks are executed of mobile telephony thanks to electronic circuits of mobile telephony, - one carries out the remainder of the tasks of localization and mobile telephony thanks to a common electronic circuit, - one divides the temporal activity of the common electronic circuit between tasks of localization and tasks mobile telephony, - assigning a higher access priority to the common circuit to mobile telephony tasks than to location tasks.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These are provided as an indication and in no way limit the invention. The figures show - Figure 1: an illustration of elements used in the device according to the invention. - Fig 2: an illustration of the sequencing of telephony tasks and location tasks.

FIG. 1 shows an apparatus 100 comprising first circuits 101 dedicated to a location activity, and second circuits 102 dedicated to a mobile telephone activity. The circuits 101 include an antenna 103 at the input. The antenna 103 receives radio signals emitted by satellites of the GPS constellation. Indeed in the example, it is considered that the circuits 101 are GPS circuits, and that the circuits 102 are GSM circuits. The GPS constellation is the set of satellites in orbit around the earth used to calculate the positions of GPS receivers. To be able to calculate a position, it is sufficient for a receiver to receive the signals transmitted by four satellites of the constellation. The satellites evolve at an altitude of about 20,000 km and transmit their signals at a frequency of 1,575.42 MHz. The signals recovered by the antenna 103 are therefore very weak. The antenna 103 is therefore followed by an amplifier 104. The output of the amplifier 104 is connected to a mixer 105. On another input the mixer 105 receives a signal from a frequency multiplier 106. The frequency multiplier 106 is on the other hand connected to a quartz 107. The oscillation frequency of this quartz is 13 MHz. It is a standard mobile phone quartz. The output of the mixer 105 is connected to an analog-to-digital converter 108. The role of the mixer 105 is to reduce the signals from the amplifier 104 to a working frequency compatible with the circuits 101. The multiplier 106 multiplies the frequency of the signal from of quartz 107 by 121, it is this signal whose frequency is a multiple of that of quartz 107 which is supplied to the mixer 105 The samples delivered by the converter 108 are processed by a correlator 109. The activities of the converter 108 and the correlator 109 are clocked by clock signals from the multiplier 106. The correlator 109 processes the samples it receives by comparing them to a replica of the signal and integrating the results of this comparison. Then at regular intervals he delivers a sample from the integration. The correlator 109 is therefore connected to a bus 110.

The bus 110 comprises all the cables, or tracks, necessary for the transport of data signals, addresses, interrupts and commands. At the same time as a sample, the correlator 109 produces a clock signal. This clock signal sequences the activity of a signal processing processor 111. The processor 111 is also connected to the bus 110. The clock signal delivered by the correlator 109 is comparable to an interrupt signal. It serves to notify processor 111 that a sample is available. These samples are stored by the correlator in a buffer memory 112. The memory 112 is connected to the bus 110. The processor 111 is controlled by instruction codes contained in a memory 113 which is also connected to the bus 110. The memory 113 contains at at least two zones, a first zone contains the instruction codes allowing the processor 111 to carry out the activity and GSM of the device 100. A second zone 115 of the memory 113 comprises instruction codes allowing the processor 111 to carry out an activity GPS.

The circuits 102 include an antenna 116. The antenna 116 receives or transmits radio signals of the GSM type. An antenna 116 is connected to a switch 117. The switch 117 is also connected on the one hand to an amplifier 118 which serves to amplify the signals received by the antenna 116, on the other hand to an amplifier 119 which serves to amplify the signals that the antenna 116 will transmit. The connection is not shown, but the switch 117 is controlled by the processor 111 via the bus 110.

The amplifier 118 is connected to a mixer 120. A second input of the mixer 120 receives a signal delivered by a multiplier 121. The multiplier 121 has as input the clock signal delivered by the quartz 107. The output of the mixer 120 is connected to an analog-to-digital converter 122. The converter 122 is connected to the bus 110. The converter 122 produces samples of the signals received by the antenna 116.

The amplifier 119 is connected to a mixer 123. This mixer 123 is also connected to the multiplier 121. It thus translates into a GSM transmission band signals produced by a digital to analog converter 124. The converter 124 produces signals which it transmits to the mixer 123 from samples which it receives via the bus 110.

The activity of the converters 122 and 124 is clocked by a clock signal from the multiplier 121. The samples produced by the converter 122, or consumed by the converter 124, are stored in a memory 125. The memory 125 is connected to the bus 110.

The apparatus 100 also includes a microprocessor 126, a memory 127 and an input-output management circuit 128. The elements 127 128, as well as the processor 111 are connected to a bus 129. In practice, the bus 129 can be confused with the bus 110. The microprocessor 126 is controlled by instruction codes contained in the memory 127. The memory 127 comprises at least one zone which corresponds to instruction codes for executing an interface between the device 100 and a user of this device . This is the 130 HMI area (man-machine interface). The circuit 128 is on the other hand connected to a screen 131 and to a keyboard 132. The microprocessor 126, controlled by the codes of the zone 130 HMI, therefore recovers the commands placed by the user of the device 100 via the keyboard 132. In an example of use, the processor 111 records the results of this processing, for example of location, in an area of the memory 127. When the user of the device 100 requests a location, the microprocessor 126 reads this area from memory 127 and display its formatted content on screen 131.

Likewise memory 127 contains an agenda area which is managed by program of this same memory. This program is executed by the microprocessor 126. Indeed, such a program does not need a lot of computing power. It is then unnecessary to use the signal processing processor 111.

For voice input-output, the device 100 includes a microphone 133 connected to an analog to digital converter 134, and a speaker 135 connected to a digital to analog converter 136. The converters 134 and 136 are connected to the bus 110. converters 134 and 136 also each have a buffer memory, not shown. When the microphone 133 receives voice samples, they are converted by the converter 134 and stored in its buffer memory while awaiting processing by the processor 111. Similarly, the processor 111 supplies the buffer memory of the converter 136. The converter 136 then only has to read its buffer memory and produce the voice signals corresponding to the samples contained in this memory.

The figure shows a succession in time of tasks carried out by the processor 111. At a frequency of the order of 250 Hz the correlator 109 produces a clock signal in the direction of the processor 111 in order to indicate to it that a sample is ready . This frequency is a multiple frequency of 50 Hz which corresponds to submultiples of 20 ms. This sample is stored in memory 112. Each pulse of the clock signal produced by the correlator 109 is called a tick. When a first tick 201 occurs, the microprocessor 111 is idle. It therefore performs a GPS task T1. The task T1 consists in applying to the samples stored in the memory 112 the processing of a loop filter. This filter allows to control the replica of the GPS signal according to the stored samples. This replica is necessary for the correlator 109. This function enslaves the replica on signals from the satellites for a maximum signal. In fact, the satellites and the user are mobile and there are therefore adjustments to be made in order to correctly receive the signals that the satellites transmit.

Once the step T1 202 is finished, we pass to a step 203 in which the microprocessor 111 performs the task T2. The task T2 is a task for preparing the samples contained in the memory 112. It may be, for example, to perform averages on the samples so that the subsequent processing is simplified and takes less time. During the execution of task T2, a tick 204 occurs.

As a task T1 has priority over the processing of a task T2, the processor 111 interrupts the processing of the task T2 203 and performs the task T1. It is task 205. Then when it has finished task T1 205, processor 111 completes task T2 203 which it had undertaken before tick 204. It is task 206.

When the task T2 has finished, the microprocessor 111 has nothing more to do, it therefore waits until a tick 207. When the tick 207 occurs, the processor 111 again performs the task T1. Then he waits until he has to perform a new task. Then occurs the tick 208. The processor 111 therefore then begins a task T1 209. During the execution of the task 209 an interruption occurs on the part of the converter 122. The processor 111 is therefore warned that the device 100 is in receiving data or voice in GSM mode. therefore interrupts task T1 and undertakes task R 210. In our example, this is voice data. The samples produced by the converter 122 are stored in an area 137 of the memory 125. During the processing of a task R, here the task 210, the processor 111 reads the samples in the area 1 of memory. It performs the necessary processing on these samples, then transfers them to the converter 136, more particularly to the temporary memory of this converter. In fact, the processor 111 produces voice samples more quickly than the converter 136 has to transfer them to the loudspeaker 135. These voice samples are therefore stored by the converter 136 in a memory, for example rotating. This memory management is also known as a queue because the last sample to enter the queue is the last to exit.

On average, a GSM reception task takes 0.5 milliseconds. When the processor 111 has finished processing the task 210, it finishes processing the task 101 which it had undertaken. This is task 211. Then it goes to sleep again, waiting for a next tick 212. Just before the tick 212, the converter 122 again warns the processor 111 that a GSM reception is in progress. The processor 111 therefore undertakes a task R 213. The execution of a task T1 214 linked to the type 212 is therefore delayed until the end of the execution of the task R 213. When it has finished the execution of task 213, the processor 111 therefore executes the task T1 214. Then the processor executes a task T2 215.

Before the end of the execution of the task T2, and before a tick 216, an interruption occurs on the part of the converter 134. This interruption warns the processor 111 that the buffer memory of the converter 134 is almost full and that it is necessary to process the samples. The processor 111 therefore interrupts the task T2 215 and undertakes an emission task E 217. During the task 217 the processor 111 reads the samples in the buffer memory of the converter 134, processes them, and stores them in a buffer zone 138 from memory 125. The microprocessor 111 simultaneously warns the converter 124 that samples are available in the memory 138. The converter 124 therefore reads the samples available in the memory 138, processes them, and transmits them via the antenna 116. Processor 111 processes samples from converter 134 memory faster than they are produced. Likewise, it fills the area 138 of the memory 1 faster than the latter is read by the converter 124. the area of the memory 125 is therefore dimensioned so as to never overflow. In practice it is sufficient that it can contain the information of a time window of the GSM standard. That is to say, information for producing 0.5 milliseconds of signal. In practice, the processing of task E takes no more than 0.5 milliseconds.

During the processing of task E 217, the tick 216 occurred. The processor 111 has taken note of it but has not interrupted the processing of the task 217 since it is a priority GSM task. Upon completion of the GSM task 217, the processor executes a task T1. Then at the end of task T1 it executes the end of task 215, that is to say a task T2. At the end of the task T2, the processor 111 ceases its activity until a tick 218. It then executes a task T1. Then when he has finished task T1 he executes a task T3.

Task T3 is a GPS task which consists in calculating the position of the GPS receiver, that is to say of the apparatus 100 as a function of the information received. The calculation algorithm is known and is contained in the GPS standard available in the official documents of this standard. The result of task T3 is therefore recorded by processor 111 in an area of memory 127.

There is also a T4 task for GPS tasks. This T4 task is a constellation monitoring task. During task T4 the processor 111 also performs a verification of the elements of the circuit 101. It verifies for example the level of the voltages on the various elements of the circuit 101.

Tasks T1, T2, T3 and T4 are GPS tasks. They are listed in order of priority. They each have a call frequency and are therefore called at regular intervals by the processor 111.

There are three GSM tasks. There is the receiving task R, the sending task E, and the service task M. GSM tasks appear asynchronously and are therefore signaled to microprocessor 111 via interrupts. The data necessary for the processing of GSM tasks are stored in buffers which are read by the processor 111. This allows a certain latency in the processing of GSM tasks. However, GSM tasks are treated as a priority over GPS tasks. That is, the processing of GSM tasks can interrupt the processing of GPS tasks.

In practice, a GSM task is temporally separated from a following GSM task by at least 4.65 ms. There is therefore always the time necessary for the execution of the GPS tasks between the GSM tasks.

Part of the tasks T4 can be performed in the microprocessor 126 (position calculation for example).

The signal for timing can be a clock signal whose frequency is equal to the frequency of production of data by the correlator, namely a frequency of the order of 10 KHz.

Claims (1)

CLAIMS 1 - Mobile device comprising first circuits dedicated to a satellite navigation activity producing digital signals for locating the device, second circuits dedicated to a mobile telephone activity producing digital voice signals, of message characterized in that the first and second circuit when combined comprises only one signal processing processor. 2 - Device according to claim 1, characterized in that the first second circuits once combined comprises only one quartz to clock these circuits. 3 Device according to claim 2, characterized in that quartz is a quartz at 13 MHz, standard mobile telephony. 4 Device according to one of claims 1 to 3, characterized in that the first circuits include a correlation circuit, or correlator, which produces a signal to clock the processor activity of signal processing. 5 Device according to claim 4, characterized in that the signal for timing is a clock signal whose frequency is equal to the frequency of production of data by the correlator, namely a frequency of the order of 250 Hz. 6 - Device according to claim 4, characterized in that the signal for clocking is a clock signal whose frequency is equal to the frequency production of data by the correlator, namely a frequency of the order of 10 KHz 7 Device according to one of claims 1 to 6, characterized in that it includes a buffer memory for storing the information produced by the first circuits. 8 Device according to one of claims 1 to 7, characterized in that it comprises a buffer memory for storing information produced by the second circuits. 9 Method of cooperation between localization tasks and mobile telephony tasks characterized in that: - part of the localization tasks are executed by means of electronic localization circuits, - part of the mobile telephony tasks are executed by means of electronic circuits of mobile telephony, - the remainder of the tasks of localization and mobile telephony are carried out by means of a common electronic circuit, - the temporal activity of the common electronic circuit is divided between tasks of localization and tasks of mobile telephony, - assigns higher priority to the common circuit for mobile telephony tasks than to localization tasks. 10 - Method according to claim 9, characterized in that the location tasks are GPS tasks. 11 - Method according to one of claims 9 or 10, the mobile telephony tasks are GSM tasks. 12 - Method according to one of claims 9 to 11, characterized in that: - the localization tasks are executed in a clocked manner, the timing being obtained by a clock signal delivered by a correlator, - the tasks of mobile telephony by interrupting localization tasks if necessary.