CN1213471A - Method and apparatus for realigning a mobile phone antenna using an inserted audio signal - Google Patents

Abstract

The mobile radiotelephone inserts an audible alignment signal into the audible radiotelephone communications, wherein the audible alignment signal is a function of the orientation of the radiotelephone. The audible alignment direction signal prompts the radiotelephone user to re-align the radiotelephone antenna direction to improve the direction of the source of communication with the radiotelephone. The acoustic alignment direction signal is preferably a function of the received signal strength of the radiotelephone communications. The audible alignment direction signal is preferably artificial noise that is inserted into the radiotelephone speaker along with the radiotelephone communications signal, thereby restoring the subjective fail-over characteristic of the received radiotelephone communications. The artificial noise is preferably used with an encoded digital radiotelephone system that attenuates the audio when a threshold below which communications are suppressed is reached. The insertion of artificial noise can also be used in variable power base stations.

Description

Method and apparatus for realigning a mobile phone antenna using an inserted audio signal

  Field of Invention

This invention relates to communication systems, and more particularly to mobile radiotelephone communication systems communicating with terrestrial base stations or orbiting satellites.

Background of the invention

Wireless communication systems are increasingly being used for wireless mobile communication. Wireless communication systems use mobile radiotelephones that communicate with terrestrial base stations or orbiting satellites. An example of a mobile radiotelephone is a cellular telephone system. The cellular telephone system is a wide area communication network using frequency reuse. Blecher described the implementation of an analog cellular telephone system in an article entitled "Advanced Mobile Telephone Services" in IEEE Transactions on Vehicular Technology, Vol. VT29, No. 2, pp. 238-244, May 1990. Design and work. Analog cellular telephone systems are also referred to as "AMPS" systems.

Recently, a digital cellular phone system has also been proposed and implemented using a Time Division Multiple Access (TDMA) structure. The Electronics Industries Association (EIA) and the Telecommunications Industries Association (TIA) have also proposed standards for a Digital Cellular (ADC) architecture for the United States, which is a dual-mode analog and digital systems. The assignee of the present invention is currently marketing telephones that have implemented the IS-54B dual-mode architecture. Different standards for digital cellular telephone systems have been promulgated in Europe. The European digital cellular system, also known as GSM, also uses the TDMA structure.

It is well known to those skilled in the art that a mobile radiotelephone includes an antenna and a transceiver for receiving radiotelephone communications via the mobile radiotelephone antenna. In vehicular mobile radiotelephones, the antenna is generally mounted on the vehicle body. In handheld mobile radiotelephones, the antenna typically protrudes from the housing of the handheld radiotelephone. Proper orientation of the antenna associated with a radiotelephone communication signal is very important for clear reception without distortion or dropped calls. As is well known, often slight changes in the direction of the antenna will result in significant improvements in radiotelephone reception. For example, a handheld phone will suffer a loss of signal strength when receiving transmissions from the other side of the user's head. Head blocking can cause a 6dB signal loss.

Because antenna orientation is so important in mobile radiotelephones, many mobile radiotelephones provide a signal strength display of received radiotelephone communications signals that prompts the user to reorient the antenna. Furthermore, the quality of received signals in analog or unencoded digital mobile radiotelephone systems tends to progressively degrade as antenna misalignment increases. Therefore, the noise level tends to increase gradually, which can prompt the user to reorient the antenna. Moving a vehicle-mounted or hand-held radiotelephone in this way can reduce the aforementioned noise.

Currently, it is common to use digital speech coding or digital error correction coding in wireless communication systems in order to improve communication efficiency. The digital encoding described above allows communication with better quality down to a signal-to-noise ratio as low as 2dB or less, and cuts off sharply below this threshold. Thus, the degraded comfort of analog FM or uncoded systems is lost and replaced by a sharp cutoff below the threshold. In such digitally coded wireless communication systems, poor orientation can cause the signal strength to drop below a threshold so that communication is cut off abruptly. A decrease in signal strength is not accompanied by an increase in noise level that would prompt the antenna to reorient.

Summary of Invention

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a system and method for aligning a mobile radiotelephone antenna in relation to received mobile radiotelephone communications.

Another object of the present invention is to provide methods and systems for directing antennas in digital mobile radiotelephones using coding techniques and thus creating a signal cutoff threshold.

SUMMARY OF THE INVENTION These and other objects are provided, in accordance with the present invention, by a mobile radiotelephone that inserts an audio alignment signal into an audio radiotelephone communication that is a function of the direction of the radiotelephone antenna. The audio alignment signal prompts the radiotelephone user to reorient the radiotelephone antenna to improve orientation relative to the source of radiotelephone communications.

Specifically, received radiotelephone communications have a received signal strength that is a function of the position of the radiotelephone antenna. In accordance with the present invention, the audio pointing signal is a function of the received signal strength of the radiotelephone communication, which is inserted into the audio radiotelephone communication. The audio alignment signal may be a direct function of the received signal strength or may be a function of another parameter that depends indirectly on the signal strength, such as distortion or noise level. The audio aiming signal is preferably artificial noise inserted into the radiotelephone speaker along with the radiotelephone communication signal, thereby restoring subjective comfort-degraded performance of receiving the radiotelephone communication. By artificially restoring subjective comfort-degraded performance, the present invention prompts the user to reorient the radiotelephone antenna to receive radiotelephone communications.

A mobile radiotelephone according to the invention includes means for receiving radiotelephone communications, said mobile radiotelephone including an antenna and a radio transceiver. The signal strength indicating means is responsive to receiving means for generating a signal strength indication that is a function of the signal strength of the received radiotelephone communication. As described above, the signal strength indication may be a direct or indirect function of signal strength. Audio sensing means responsive to receiving means and signal indicating means to generate an audio signal combining received radiotelephone communications and signal strength indications to provide audio signal strength indications in conjunction with audio radiotelephone communications, said audio sensing means generally comprising one or Multiple speakers or earbud speakers and may include voice codecs and other circuitry.

The present invention is particularly useful for digitally coded radiotelephones or other mobile radiotelephones in which the receiving means is a sharp cutoff receiving means which generates an audio radiotelephone communication signal when the received radiotelephone communication signal is above a threshold, and The receiving means suppresses or cuts off the audio radiotelephone communication signal when the received radiotelephone communication signal is below a threshold. For such radiotelephones, the signal strength indicating means generates an alert signal that is a function of the received strength of the radiotelephone communications signal to notify that the received signal strength is approaching a threshold.

The signal strength indicating means preferably includes means for generating an artificial noise which increases as a function of a decrease in received signal strength of the radiotelephone communication signal, thereby indicating that the received signal strength is deteriorating or approaching a threshold. The increase in artifacts is preferably a function of the decrease in received signal strength from the received signal strength above the threshold received signal strength below the threshold, thereby indicating that the received signal strength is approaching the threshold and has passed threshold. However, an audible indication of increasing strength with increasing signal strength may also be used. Thus, even after the radiotelephone communication signal has been suppressed, the artificial noise level can prompt the user to reorient the antenna which will restore communication.

Man-made noise can be any signal that differs from received radiotelephone communications and varies as a function of antenna direction. For example, the artificial noise may be broadband white noise or typical noise, a single sinusoidal frequency that varies in amplitude or frequency as signal strength decreases, or multiple sinusoidal frequencies that vary in amplitude or frequency as signal strength decreases. Alternatively, the man-made noise may be a periodic signal to indicate that the received signal strength is deteriorating or approaching a threshold, such as clicks or chirps, whose repeated periodic changes are received as signals for radiotelephone communications. A function of the change in signal strength. The above-mentioned changing periodic signal may be similar to a wireless tuning indication. Man-made noise may be a synthesized voice message, such as the audible word "movement," that increases in amplitude or frequency as received signal strength decreases.

The invention is also particularly useful for mobile radiotelephones with automatic power control (APC) used at the transmitter (terrestrial base station or satellite). The transmit power control system described above causes the transmitter to increase its power in response to an indication from the mobile radiotelephone that the mobile radiotelephone is receiving a lower signal strength. This automatic power control system provides a tighter threshold because it prevents the slow decrease in received signal strength that the automatic power control system can track until no more power is provided.

In accordance with the present invention, a transmitter communicates with a radiotelephone to transmit a power indicating signal. The audio alignment direction signal is also generated in response to the transmit power indicating signal received by the radiotelephone, thereby generating a signal strength indication that is a function of the signal strength of the received radiotelephone communication and the signal strength of the received radiotelephone communication. function of transmit power. Thus, as the transmit power is increased, for example, the amount of artificial noise inserted also increases, thereby prompting to reorient the antenna so that a reduced transmit power can be used.

The present invention prompts the user to reorient the radiotelephone antenna for better reception by inserting an audible artificial noise signal into the audible radiotelephone communications. Improved mobile radiotelephone communications are provided by being able to prompt the user to reorient the antenna before achieving audio degraded communications.

A brief description of the drawings

Figure 1 is a block diagram of a mobile radiotelephone that may be used with the present invention.

Figure 2 is a block diagram of a receive digital signal processor (DSP) which generates an alignment signal in accordance with the present invention.

Figure 3 illustrates the operation of generating a first alignment signal in accordance with the present invention.

Figure 4 illustrates the operation of generating a second alignment signal in accordance with the present invention.

Fig. 5 is a block diagram of processing received signals according to a second embodiment of the present invention.

Fig. 6 is a block diagram of a demodulator according to a second embodiment of the present invention.

  Preferred Embodiment Detailed Description of the Invention

Hereinafter, the invention will be described in more detail with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. However, this invention may also be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the figures.

Referring now to FIG. 1, there is shown a functional block diagram of a mobile radiotelephone that may be used with the present invention. Mobile radiotelephone 100 may be a vehicular mobile radiotelephone, but is preferably a handheld mobile radiotelephone. Mobile radiotelephone 100 typically receives radiotelephone communications from terrestrial base stations 155 or satellites in orbit (not shown). Figure 1 is a simplified representation of a dual-mode cellular radiotelephone as described in U.S. Patent Application Serial No. 07/967,027, entitled "Multimode Signal The aforementioned dual-mode cellular radiotelephones are described in more detail in "Processing", the disclosure of which is hereby incorporated by reference.

Briefly, antenna 145 , wireless transceiver 140 , and receive digital signal processor (DSP) 125 function as means for receiving radiotelephone communications 150 . Receive DSP 125 processes signals received from the wireless transceiver via DSP interface 135, and it generates digital audio signals that can be loaded into speech codec 115 for transmission through an audio transducer (eg, speaker 110). The transmit DSP 120 receives the digital voice signal from the microphone 105 via the voice codec 115 and it generates the signal which is sent by the wireless transceiver 140 and antenna 145 to the DSP interface. Microcontroller 130 controls some or all of the components of mobile radiotelephone 100 . The design of mobile radiotelephone 100 is well known to those skilled in the art and need not be described in detail here.

The present invention is preferably implemented in part as a stored program executable on a receiving DSP 125, such as a Texas Instruments C53 digital signal processor (Texas Instruments C53 DSP). However, the invention may also be implemented or partially implemented as a stored program executable on microcontroller 130 or another processor. Alternatively, a custom logic design or a combination of software and hardware can be used. Analog devices may be used in analog radiotelephone systems.

Referring now to FIG. 2, a block diagram of the receive DSP 125 of FIG. 1 configured in accordance with the present invention will be described. As shown in FIG. 2, receive DSP 125 includes communication signal generating means 210 which generates digital receive radio communication (voice) signals 250 from radiotelephone communications received from DSP interface 135. Communication signal 250 is applied to voice codec 115 for conversion to an analog signal which is provided to speaker 110 for producing audio radiotelephone communications. Communication signal generating means 210 may include digital speech decoding and error correction functionality to produce a sharp cutoff receiver using techniques known to those skilled in the art. In such coded digital systems, an audible radiotelephone communication signal is generated when the strength of the received signal for the radiotelephone communication is above a first threshold, and suppressed when the strength of the received signal is below the first threshold. Audio frequency radiotelephone communication signal.

Still referring to FIG. 2 , the receiving DSP 125 also includes an alignment signal generator 220 . Aim direction signal generating means 220 may receive an indication from DSP interface 135 that a signal-to-noise ratio has been received. As understood by those skilled in the art, wireless transceiver 140 may generate signals indicative of received signal strength. Alternatively, receiving DS1P 125 or microcontroller 130 may generate a signal indicative of received signal strength based on the received wireless communication. The generation of signals indicative of received signal strength is well known to those skilled in the art and requires no further description. Aim direction signal generating means 220 generates an aim direction signal or alert signal 240 which is a function of the received signal strength of the radiotelephone communication signal.

The alignment direction signal 240 is inserted into the audio wireless communication signal by combining the digital received wireless communication signal 250 and the alignment direction signal 240 at the summer 230 . Summer 230 produces combined signal 260 that is provided to voice codec 115 for conversion to an analog signal and broadcast via speaker 110 . It can be appreciated that it is not necessary to combine the wireless communication signal 250 and the alignment direction signal 250, but as long as the audio alignment signal is inserted into the audio radiotelephone communication, the above-mentioned wireless communication signal 250 and the alignment direction signal 250 are provided separately to one or Multiple speakers or headphones 110 . In the embodiment of FIG. 2, the aiming signal processing means 220 and summer 260 constitute intervening means for inserting the audio aiming signal which is a function of the radiotelephone antenna directivity into the audio radiotelephone communication. Audio sensor means, such as speaker 110 and speech codec 115, are responsive to receive digital processing 125 to generate an audio signal combining received radiotelephone communication signal 250 and aiming direction signal 240 for inserting an audio signal strength indication into the audio radiotelephone communication.

Referring now to FIG. 3, the operation of a first embodiment for generating an alignment signal (block 220 of FIG. 2) will now be described. Specifically, at block 310, an increasing signal is generated as a function of decreasing received signal strength. At block 320 , an artificial noise signal is generated and scaled or amplified from the signal generated at block 310 . Thus, an increased artificial noise is generated whose magnitude is a function of decreasing received signal strength, thereby providing an artificial indication of a gradual deterioration in signal strength. At block 330, the amplified artificial noise is inserted into the audio radiotelephone communication.

A man-made noise signal as understood by those skilled in the art may be white noise, typical noise, or any other type of broadband noise, or may be noise of a single frequency or multiple frequencies, such as sinusoidal noise or multiple sinusoidal noises, whose amplitude Increases or decreases as received signal strength decreases. It is preferable to choose an audio frequency indication that increases with signal strength to have a "comfortable" character, such as a musical key chord tone, however, an audio frequency indication that increases with a deteriorating signal will have an "uncomfortable" character, such as white noise or dissonant tones . In digital systems that provide a cut-off threshold below which communication ceases, the artificial noise signal preferably becomes audible above the threshold and becomes stronger when the received signal strength exceeds the threshold, and alerts the user below the threshold Reorient the radiotelephone antenna to restore communication.

Referring now to FIG. 4, a second embodiment of generating alignment direction signal 220 of FIG. 2 will now be described. At block 410 , a first increasing signal is generated as a function of decreasing received signal strength, as already described in connection with block 310 . At block 420, a second signal is generated that increases as a function of increasing transmit power.

It will be appreciated by those skilled in the art that in a mobile radiotelephone system using automatic transmit power control, base station 155 (FIG. 1) or satellite responds to an indication that mobile radiotelephone 100 is receiving a signal strength lower than desired in order to increase its transmit power. power, and it responds to an indication that the mobile radiotelephone 100 is receiving a greater than desired signal strength to reduce its transmit power. In accordance with the present invention, an indication of base station or satellite transmit power is provided in the downlink transmit direction of radiotelephone communications 150 received by a mobile radiotelephone. Accordingly, at block 220, a second signal is generated that increases as a function of increasing transmit power from the network. Thus, the feedback control audio indication from the network prompts the user to realign his antenna direction to improve either uplink or downlink.

Continuing with the description of FIG. 4, at block 430, the first and second signals are combined to produce a third signal that varies as a function of the first and second signals. For example, the third signal will increase as a function of decreasing received signal strength, and it also increases as a function of increasing transmitted power. Therefore, when increasing the generation power, the alignment signal will increase to prompt the user to re-orient the antenna so that the transmitter can generate lower transmit power. At block 440, an alignment direction signal is generated. At block 440, the artificial noise signal is a periodic signal, such as a sine wave or click, whose frequency varies based on the value of the third signal. Thus, the aforementioned variable frequency artifact signal provides an indication of tuning, eg, where higher frequencies indicate lower signal strength and higher transmit power. At block 450, artificial noise is inserted into radiotelephone communications.

Thus, the present invention produces an audible aiming signal that is a function of the directivity of the radiotelephone antenna (and possibly the transmit power of the base station or satellite), which is indicative of the radiotelephone antenna receiving radiotelephone communications. Is the alignment direction or no alignment direction. The user is then prompted to realign the antenna so that the orientation signal decreases. The present invention provides a comfort degradation indication that can be used in analog systems to provide an indicator of comfort degradation before actual system noise starts to intervene, and it also provides a digital system that can use codes to indicate that a system is approaching or has Passed the cutoff threshold. Prompts the user to reorient the antenna and restore a high quality signal.

Referring now to Figure 5, a second embodiment of the present invention is illustrated. Figure 5 illustrates different layouts of the block diagram for receive signal processing either within the radiotelephone or within the transmitter (terrestrial base station or satellite). FIG. 5 is a functional layout diagram corresponding to the hardware layout of FIG. 1 .

Signals including noise and interference are received by antenna 145 and are down-converted by wireless transceiver 140 and digitized to obtain a signal representation suitable for digital signal processing. Receive DSP 125 processes the transformed received signal to perform demodulation and error correction decoding function 500 to obtain digital symbols representing encoded speech. The coded voice is further decoded in the DSP125 and converted into an analog voice by the CODEC115. The function of the CODEC115 is named as block 510 in FIG. 5 . Block 510 also decodes command messages and passes them to control processor 130 . Block 500 also generates a signal quality indicator representing the error-free probability that the decoded bits are passed to speech decoding 510 .

Speech coder 510 may include the ability to ignore bits indicating unreliability and output a default speech sound or otherwise hide the effects of erroneous bits by known "speech parameter interpolation" methods. Error concealment can include "comfort" noise output during unreliable signals. Comfort noise avoids abruptly terminating all audio output, which gives the unwanted impression of "clipped" speech. According to an embodiment of the present invention, the demodulation and decoding function 500 can additionally output a signal representing the radio noise rejected during the decoding process, as will be described below.

According to U.S. Patent Application Serial No. 08/305,727, filed September 14, 1994, entitled "Channel Independent Equalizer Apparatus," issued to co-inventor Dent, demodulation may be performed by a Maximum Likelihood Sequence Estimator and error correction decoding, the disclosures of which are hereby incorporated by reference. Referring to Figure 6, the Viterbi sequence maximum likelihood sequence estimator includes a state memory 65 for storing a plurality of hypothesized received symbol sequences together with each path metric representing a cumulative probability. Processing includes the use of a transmitter module 60 which may include a model of the propagation channel from processing a known sequence of bits called training sequences or symbols. The latter information is implemented in the reference vector array of the state memory.

The transmitter model 60 computes expected signal values that at each round correspond to a new bit hypothesis based on the previous hypothesis being true. The expected signal value is compared with the received signal value in a comparator 61 to obtain a difference. The difference is a measure of the error between the assumption and the actual received signal sample, where the error is due to wireless noise only if the assumption is correct. A mismatch indication is added to the previous path metric corresponding to the tested hypothesis to obtain a new cumulative mismatch or path metric.

The adder 62 constitutes a new path metric from the state containing the leftmost bit of the memory equal to a binary "0" in the current hypothesis, and the adder 64 constitutes a binary "1" corresponding to the leftmost bit position of the memory corresponding to the current hypothesis. The new path metric. The comparator compares the two new path metrics and selects the lower of the associated state memory and all corresponding contents to employ a left shift from the leftmost bit of the current assumption (which may be 0 depending on the state given the lower path metric Or it could be 1) and go into the already processed part of the memory and become the new content of the state memory. Both "0" and "1" are used as hypotheses for new bits in order to test all previous hypotheses, and after processing all hypotheses, the number of remaining states will be the same as before, and all path metrics will be updated Take the lower of the two compare metrics and advance the decoding of one symbol.

The operation of Figure 6 is described in more detail in connection with this patent application. Embodiments in accordance with the invention can modify the above description to provide an indication of tuning noise.

As previously described, the comparator 61 calculates the difference between the assumed signal value and the actual received signal value due to only radio noise when the assumed signal value is true. Rather than discarding the difference calculated above, embodiments of the present invention record the difference along with each data symbol of the already processed portion of the state memory. As the error correction code produces several transmitted samples for each of the original data bits to be transmitted, the transmitter model 60 will likewise produce several signal samples for comparison and the comparator 61 will test the multiple samples value to get several differences. These differences are usually combined as a sum of squares to give an indication of the mismatch before discarding.

According to an embodiment of the present invention, a difference value is stored in state memory 65 corresponding to each processed bit decision. When one of the two compared hypotheses is selected as a survivor by the Viterbi method, the stored difference from one state is allowed to overwrite the stored difference from the other state. The final bit decision performed by the Viterbi MLSE processor is the bit that minimizes the sum of squared differences. Therefore, the remaining errors may be due to just wireless noise rather than incorrect bit decisions. Therefore, the stored difference is equal to the received wireless noise and can be output to the speech decoder 510 . Speech encoder 510 can add radio noise samples to the audio signal so that the user will hear an accurate representation of the radio noise characteristics that scale with the signal-to-noise ratio rather than by the sharp cutoff threshold of the decoding process.

Digital radiotelephones employing digitization of speech signals often incorporate not only error detecting coding but also error correcting coding, for example, a cyclic redundancy check (CRC) is often added to the most sensitive important bits within digital speech transmissions. When the CRC check fails, the erroneous bits are prevented from causing unwanted audio artifacts by various "de-burping" error masking strategies, which are also known. Such hiccupping techniques are able to maintain useful voice quality when the CRC fails 5% of the time. CRC failure detection for more than 5% of the time amount can be used to trigger automatic addition of an audio signal quality indication to the phone output in order to induce the user to take correct action.

The embodiments described above illustrate that it is possible in principle to extract from the demodulation and decoding process any noise representation close to true wireless noise and artificially reintroduce the audio signal to give a true indication of rising or falling signal quality, independently of on the threshold characteristics of the demodulator.

It may be desirable to provide an audible indication of signal quality rising or falling in an accentuated manner relative to the signal-to-noise ratio. For example, it may be desirable that a 1 dB reduction in signal-to-noise ratio should be indicated to the user by 3dB or 6dB indicated with an artificially increased audible frequency. This can be achieved using stored path metrics from the decoding process, or alternatively using stored wireless noise waveforms. The path metric is proportional to the mean square of the radio noise and can be used to scale the audio indication to the radio noise or indeed to any power of the radio noise level.

The audio indication thereby scaled can be a pre-stored audio waveform if desired to reduce the complexity of the demodulator and decoding process. As explained earlier, this waveform can be chosen to be an "uncomfortable" sound when indicating degrading signal quality. Conversely, when inversely proportional to the determination, dividing by the power of the path metric, a "comfortable" waveform, such as a main musical chord, can be used so that its strength increases with increasing signal quality. A combination of uncomfortable sounds that increase with noise level and comfortable sounds that increase with signal level can also be used, but at least the "comfortable" sound will Should be audio to keep it from being distracting during conversations with voices that don't have a good signal-to-noise ratio.

Alternatively or additionally the network may send a command message as previously described to the controller 130 to remotely turn on or off the audible indication to reorient the antenna. Such commands may be issued by the network either based on the signal strength measured by the mobile phone and sent as a signal strength report to the network or based on the measured signal strength received by the network receiver from the mobile phone's transmission or a combination of the two .

It may also be desirable for an audible tone to indicate to the user that the signal quality is not in a call when their phone is periodically receiving signal bursts on the talk channel. In order to save battery power, the mobile phone does not wake up in idle mode to receive continuously but only in what is here called a sleep mode pre-assigned by the network to each mobile unit. For example, this may occur at intervals of only 1 second(s). The network knows when the mobile receiver will be awake and call reminders to the receiver are sent only during said times. Using the received signal at intervals of only 1 second(s) may be too slow to provide the user with an indication of the signal quality of the idle state optimized by moving the antenna position. If necessary, the user can be required to enable the audible indication by pressing a key which, when the phone is in idle mode, temporarily causes the receiver to operate continuously or at least frequently enough to measure Signal strength in the direction of the antenna.

When not in a call, there is no shortage of audio indications that provide various "comfort sensations" such as a musical hum that rises with improved signal quality strength. The instruction "for maximum hum alignment" can then be abbreviated within the device user manual, which is an easy-to-follow instruction for the user. Different "buzzes" can be provided, depending on the characteristics of the network station to which the phone is locked, for example, a "spaced buzz" when the phone is locked to a land-based cellular system.

Exemplary preferred embodiments of the present invention are disclosed in light of the drawings and detailed description, and although specific terms are employed, they are used in a generic and descriptive sense and not for purposes of limitation, the invention set forth in the following claims middle.

Claims (41)

1. A mobile radiotelephone comprising: Antennas for mobile radiotelephones; means for receiving radiotelephone communications via the mobile radiotelephone antenna described above; means responsive to said receiving means for converting received radiotelephone communications into audio radiotelephone communications; and means for inserting an audio alignment signal into an audio radiotelephone communication responsive to said receiving means, thereby prompting a user of the radiotelephone to realign said radiotelephone antenna to improve alignment relative to received radiotelephone communications, wherein The audio alignment signal described above is a function of the orientation of the radiotelephone antenna. 2. A mobile radiotelephone according to claim 1, wherein said receiving radiotelephone communication includes a received signal strength, said received signal strength being a function of the position of said radiotelephone antenna, said insertion means including a A means for an audio point-of-view signal which is a function of received signal strength of received radiotelephone communications. 3. A mobile radiotelephone according to claim 2, characterized in that, wherein said receiving means includes sharp cutoff receiving means for suppressing received radiotelephone communications when the received signal strength of the received radiotelephone communications is below a threshold; and wherein said means for inserting includes means for inserting an audio alignment signal as a function of the received signal strength of the radiotelephone communication signal for notification that the strength of the received signal has fallen below a threshold. 4. 3. A mobile radiotelephone according to claim 3, wherein said sharp cutoff receiving means comprises digitally encoded radiotelephone receiving means. 5. A mobile radiotelephone according to claim 1, wherein said insertion means includes means for inserting artificial noise into the audio radiotelephone communication which varies as a function of the directionality of the radiotelephone antenna. 6. A mobile radiotelephone according to claim 2, wherein said inserting means includes means for inserting artificial noise into the audio radiotelephone communication, said artificial noise increasing in magnitude in response to a decrease in received signal strength of the radiotelephone communication signal. 7. A mobile radiotelephone according to claim 2, wherein said inserting means includes means for inserting periodic artificial noise into the audio radiotelephone communication, the period of said artificial noise varying in response to a decrease in received signal strength of the radiotelephone communication signal. 8. A mobile radiotelephone according to claim 1, wherein said inserting means is further responsive to transmit power indicative of a signal received by said receiving means for inserting an alignment signal, said alignment signal being wireless A function of both the orientation of the telephone antenna and the transmit power of received radiotelephone communications. 9. A mobile radiotelephone according to claim 1, characterized in that, wherein said converting means comprises means for rejecting noise from received radio telecommunication communications; estimating means has been used to produce an estimate of the noise rejected from received radio telecommunication communications; and wherein said means for inserting comprises means responsive to said means for estimating, means for generating an audible indication signal which varies as a function of the estimate; and means for inserting the audible indication signal into the audio radiotelephone communication. 10. 9. A mobile radiotelephone according to claim 9, wherein said estimating means includes an error correction decoder including path metric means. 11. 9. A mobile radiotelephone according to claim 9, wherein said estimating means comprises a Viterbi sequence maximum likelihood sequence estimator. 12. A mobile radiotelephone according to claim 9, wherein said estimating means comprises: means for computing expected radiotelephone communications responsive to said receiving means; means responsive to said computing means for comparing the expected radiotelephone communication with the received radiotelephone communication to obtain a difference between the expected radiotelephone communication and the received radiotelephone communication; and Means for generating an error signal based on the resulting difference in response to said comparing means. 13. A mobile radiotelephone according to claim 1, wherein said received radiotelephone communication includes a cyclic redundancy check, said intervening means including means for aligning an audio frequency that is a function of cyclic redundancy check failure The direction signal is inserted into the device receiving the radiotelephone communication. 14. A mobile radiotelephone according to claim 1, wherein said inserting means includes means for inserting an alignment signal for audio comfort that is a function of the increased received signal strength of received radiotelephone communications, and means for inserting an aiming direction signal of audible discomfort as a function of reduced received signal strength of received radiotelephone communications. 15. The mobile radiotelephone according to claim 1, wherein said switching means comprises: Means for rejecting noise from received radiotelephone communications; error detection means for detecting that said rejecting means is incapable of rejecting noise from received radiotelephone communications, responsive to said rejecting means; error concealment means for masking unrejected noise effects in received radiotelephone communications, responsive to the error detection means described above; Wherein said insertion means responds to said error detection means. 16. A base station for communicating with mobile radiotelephones within a mobile radiocommunication system, comprising: variable power transmitting means for transmitting wireless communications to the mobile radiotelephone at a power level that varies as a function of the position of the mobile radiotelephone relative to the base station; and Means for causing said variable power transmitting means to transmit an indication of a transmission power level of a wireless communication to a mobile radiotelephone. 17. The base station according to claim 16, wherein said base station is a ground base station or a satellite base station. 18. Mobile radiotelephones, including: means for receiving radiotelephone communications; signal strength indicating means for generating a signal strength indication responsive to said receiving means, said signal strength indication being a function of the signal strength of received radiotelephone communications; and and audio sensing means responsive to said receiving means and said signal strength indicating means for generating an audio signal combining received radiotelephone communications and said signal strength indication to provide an audio signal strength indication together with the audio radiotelephone communication. 19. A mobile radiotelephone according to claim 18, wherein said receiving means includes a sharp cutoff receiving means for generating an audio radiotelephone communication when the received radiotelephone communication has a signal strength above a threshold signal for suppressing audible radiotelephone communications when the signal strength of received radiotelephone communications is below a threshold; and Wherein said signal strength indicating means comprises means for generating a signal strength indication to indicate that the received signal strength is approaching a threshold, said signal strength indication being a function of the received signal strength of the radiotelephone communication signal. 20. 20. A mobile radiotelephone according to claim 19, wherein said sharp cutoff receiving means comprises digitally encoded radiotelephone receiving means. twenty one. A mobile radiotelephone according to claim 19, wherein said signal strength indicating means includes means for generating an artificial noise to indicate that the received signal strength is decreasing towards a threshold, said artificial noise being of magnitude as a radiotelephone Communication signals decrease as a function of received signal strength. twenty two. A mobile radiotelephone according to claim 21, wherein said signal strength indicating means includes means for generating an artificial noise from a received signal strength above said threshold to a received signal strength below said threshold so that means for indicating that the received signal strength has decreased below a threshold, the magnitude of said artificial noise increasing as a function of the decreased received signal strength of the radiotelephone communications signal. twenty three. A mobile radiotelephone according to claim 19, wherein said signal strength indicating means includes means for generating a periodic man-made noise to indicate that the received signal strength is decreasing towards a threshold value, the periodicity of said man-made noise serving as a radio frequency signal. Telephone communication signals vary with received signal strength. twenty four. A mobile radiotelephone according to claim 23, wherein said signal strength indicating means includes means for generating a periodic artificial signal strength from a received signal strength above said threshold to a received signal strength below said threshold. Noise means for indicating that received signal strength has dropped below a threshold, the amplitude of said periodic man-made noise being varied as a decrease in received signal strength of a radiotelephone communication signal. 25． A mobile radiotelephone according to claim 18, wherein said signal strength indicating means is further responsive to transmit power indicative of signals received by said receiving means to generate a signal strength indication, said signal strength indication being received by the radiotelephone A function of both the signal strength of the communication and the signal transmission power of the received radiotelephone communication. 26． A mobile radiotelephone according to claim 18, wherein said signal strength indicating means comprises: Means for rejecting noise from received radiotelephone communications; Estimating means for generating an estimate of noise rejected from received radiotelephone communications; Wherein the above-mentioned signal strength indication is a function of estimation. 27． 26. A mobile radiotelephone according to claim 26, wherein said estimating means includes an error correction decoder including path metric means. 28． 26. A mobile radiotelephone according to claim 26, wherein said estimating means comprises a Viterbi sequence maximum likelihood sequence estimator. 29． A mobile radiotelephone according to claim 26, wherein said estimating means comprises: means for computing expected radiotelephone communications responsive to said receiving means; means responsive to said computing means for comparing the expected radiotelephone communication with the received radiotelephone communication to obtain a difference between the expected radiotelephone communication and the received radiotelephone communication; and Means for generating an error signal based on the resulting difference, responsive to the above comparing means. 30． A mobile radiotelephone according to claim 18, wherein said received radiotelephone communication includes a cyclic redundancy check, said signal strength indicating means comprising means for generating a signal strength indication, said signal strength indication being at A function that receives a failure of a cyclic redundancy check within a radiotelephone communication. 31． A mobile radiotelephone according to claim 18, wherein said signal strength indicating means includes means for generating an audible comfort alignment signal which is a function of increased received signal strength of received radiotelephone communications and means for generating an alignment direction signal of audible discomfort as a function of reduced received signal strength of received radiotelephone communications. 32． A mobile radiotelephone according to claim 18, wherein said signal strength indicating means comprises: Means for rejecting noise from received radiotelephone communications; error detection means for detecting that said rejecting means is incapable of rejecting noise from received radiotelephone communications, responsive to said rejecting means; and Error concealment means for masking unrejected noise effects in received radiotelephone communications responsive to the above described error detection means. 33． An antenna alignment direction indicating method for a mobile radiotelephone for receiving radiotelephone communications via a mobile radiotelephone antenna, said mobile radiotelephone converting received radiotelephone communications into audio communication signals, said and antenna alignment direction indicating method comprising the steps of: inserting an audio alignment signal into an audio radiotelephone communication, thereby prompting a user of the radiotelephone to reorient said radiotelephone antenna to improve alignment relative to received radiotelephone communications, wherein said audio alignment signal is A function of the directivity of a radiotelephone antenna. 34． An antenna alignment method according to claim 33, wherein said receiving radiotelephone communication includes a received signal strength, said received signal strength being a function of the position of said radiotelephone antenna, said intervening means comprising A step of: An audio pointing signal is inserted into the audio radiotelephone communication, said audio pointing signal being a function of received signal strength of the receiving radiotelephone communication. 35． 34. The antenna alignment method of claim 34, wherein said step of inserting includes the step of inserting artificial noise that varies as a function of radiotelephone antenna directivity into audible radiotelephone communications. 36． The antenna alignment method of claim 34, wherein said inserting step includes the step of inserting artificial noise into the audio radiotelephone communication, said artificial noise increasing in magnitude in response to a decrease in received signal strength of the radiotelephone communication signal . 37． The antenna alignment method of claim 34, wherein said inserting step includes the step of inserting periodic man-made noise into audio radiotelephone communications, said man-made noise periodically responding to a decrease in received signal strength of a radiotelephone communication signal And change. 38． The antenna alignment direction indicating method according to claim 33, wherein said mobile radiotelephone further receives a transmit power indicating signal, and wherein said step of inserting comprises the steps of: An aiming signal is inserted into the audio radiotelephone communication, said aiming signal being a function of both the directivity of the radiotelephone antenna and the transmit power of the received radiotelephone communication. 39． The antenna alignment direction indicating method according to claim 33, characterized in that, wherein said mobile radiotelephone includes means for rejecting noise from received radiotelephone communications; and estimating means for generating an estimate of the rejected noise from received radiotelephone communications; and Wherein said step of inserting includes the steps of generating an audio indication signal that varies as a function of the estimate; and inserting the audio indication signal into the audio radiotelephone communication. 40． An antenna alignment method according to claim 33, wherein said received radiotelephone communication includes a cyclic redundancy check, said step of inserting includes the step of inserting an audio alignment signal, said audio alignment signal The signal is a function of the failure of the cyclic redundancy check within the received radiotelephone communication. 41． The antenna alignment direction indicating method according to claim 37, wherein said inserting step comprises the steps of: inserting an audio comfort orientation signal that is a function of increased received signal strength of received radiotelephone communications; and An audio-discomfort-alignment signal is inserted as a function of the reduced received signal strength of the received radiotelephone communication.

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