53 results about "Digital mobile radio" patented technology

The invention discloses a method for transmitting a backward control signaling by using a control channel in a digital mobile radio (DMR) system. The method is characterized by comprising the following steps of: adding a control channel time slot structure into the control channel in a complementary definition way; using a part of bits of originally transmitted payload information as the carried backward control signaling by the control channel time slot structure; and complementally defining added type fields of the control channel time slot structure by using a synchronous word which is consistent with downlink data so as to differentiate the type fields from the control information without carrying backward control signaling. By the method, the backward control information can be transmitted by using the control channel in an alignment mode of a DMR cluster communication system, so that a base station can realize backward control over a mobile station, and the base station can transmit a short broadcast signaling in the control channel without affecting the synchronization performance of the mobile station or interrupting the information transmission of a service channel while realizing the backward control.

The invention relates to a method for realizing wireless access of DMR (Digital Mobile Radio) digital-trunked grouped data, which is characterized by comprising the following steps of: firstly, newly adding a data access application signaling in the upstream access process of the grouped data of a mobile station; secondly, realizing access control by adding corresponding fields in the data heads of response data on the downstream channel control of a base station; and thirdly, adding reserved access control parameter fields of tail blocks of the data to be confirmed in the downstream data sending process of the base station, then making the base station carry out channel access control while accomplishing downstream data sending to reserve time slots required for the mobile station to send the response data, and setting a channel-occupied identification in a common announcing channel, thereby ensuring that the mobile station can occupy response data information returned by the channel in time. The invention improves the channel access success rate of the mobile station in the process of transmitting the grouped data, reduces time slot waste caused by collision when the grouped data is randomly accessed to the channel and improves the utilization rate of the channel.

The invention belongs to the field of wireless communication and relates to an incoherent detection technology suitable for a DMR (Digital Mobile Radio) digital trunking communication system. Firstly, defects of both a conventional incoherent detection technology and an existing multiple symbol detection algorithm are analyzed in detail; then according to the maximum likelihood ratio criterion, an incoherent multiple symbol detection algorithm suitable for a 4-CPFSK (Continuous Phase Frequency Shift Keying) signal in a DMR standard frame is disclosed; and simultaneously, a decomposed linear signal replaces an original reference signal to simplify the structure of a receiver. The receiver corresponding to the algorithm disclosed by the invention is formed by three front-end matched filters and a following viterbi operational part and the complexity of the receiver is effectively reduced. When the calculation of the branch metric is carried out, the judgment accuracy is improved by utilizing information of a plurality of pieces of code element time. A computer simulation result in the Matlab environment proves that with the increase of observing windows, the performance of detecting the 4-CPFSK signal of the algorithm disclosed by the invention gradually becomes better.

The invention discloses an automatic offline method under a DMR (Digital Mobile Radio) transit mode, comprising the following step: when a communication system is in the transit mode, if a DMR terminal dose not receive an effective frame from a downlink of a repeater after transmitting activated frames to the repeater for set times, the DMR terminal automatically switches transmitting frequency into the transmitting frequency of the repeater to carry out information transmission in a through mode. According to the invention, the success rate of communication can be greatly enhanced under the condition that the downlink can not receive the effective frame of a base station; smooth switching is realized without user intervention; and the automatic offline method is more suitable for application to the aspect of emergency.

A method, apparatus, and system for application controlled network selection between a broadband network and a narrowband network include operating an application with an end device with a narrowband connection to the end device; acquiring a source broadband connection comprising a source broadband network address; negotiating a peer-to-peer broadband connection with the end device utilizing the narrowband connection to communicate the source broadband network address; utilizing the peer-to-peer broadband connection for data associated with the application responsive to successful negotiating; and managing the peer-to-peer broadband connection using the narrowband connection as a control channel therefor. The narrowband connection can include Digital Mobile Radio (DMR), Land Mobile Radio (LMR), Project 25 (P25), Terrestrial Trunked Radio (TETRA), or the like.

The invention provides a method for reducing the power consumption of a DMR (Digital Mobile Radio) terminal circuit. The method comprises the steps as follows: a transmitting power adjustment parameter of a receiving terminal is calculated and acquired by an emitting terminal through measuring and receiving the radio frequency signal field strength data; the power adjustment parameter is transmitted to the receiving terminal by the emitting terminal through an RC signaling channel; the transmitting power in the next time slot is adjusted by the receiving terminal according to the received power adjustment parameter. The method for reducing the power consumption of the DMR terminal circuit, provided by the invention does not rely on the sleep/wake up power saving mechanism of the system base station; and besides, the transmitting power can be adjusted dynamically by every terminal in a specific mode, so that the consumption of batteries is reduced to a greater extent, the average power consumption of the DMR terminal circuit is effectively reduced, the standby and duration of a DMR terminal battery is prolonged, and meanwhile, the electromagnetic environmental pollution of wireless communication equipment is reduced.

The invention provides a method for reducing the power consumption of a circuit in a DMR (Digital Mobile Radio) terminal and the circuit implementing the method. The method comprises the following steps: monitoring the field strength data of a radio-frequency signal by a digital signal processor DSP of the terminal; if the field strength data value of the radio-frequency signal exceeds the upper limit value of a power-saving field strength threshold, outputting a control signal by the processor, and converting the operating mode of a power converter into a PFM (Pulse Frequency Modulte) mode; if the field strength data value of the radio-frequency signal is lower than the lower limit value of the power-saving field strength threshold, outputting the control signal by the processor, and converting the operating mode of the power converter into a PWM (Pulse Width Modulte) mode. According to the method for reducing the power consumption of the circuit in the DMR terminal provided by the invention, independent of the dormancy awakening power-saving mechanism of a system base station, each terminal can dynamically adjust the power-supply efficiency at a specific mode, and the battery consumption can be saved to a greater degree, so that average power consumption of the circuit of the DMR terminal is effectively reduced, and the standby durance time of a DMR terminal battery is prolonged; meanwhile, the electromagnetic environment pollution of wireless communication equipment is also reduced.

A method for indicating padding in a digital mobile radio is disclosed. The method comprises receiving a packet comprising a header and a defined length blocks portion. The defined length blocks portion comprises payload and a padding portion. The padding portion comprises padding and a payload pad count field. The method further indicates by a pad field in the header to examine the payload pad count field to determine an amount of padding for the padding portion of the defined length blocks portion. The method further indicates an amount of padding for the padding portion in the payload pad count field.

The invention discloses a method for receiving and the transporting signals of digital mobile radio and television which includes china digital television terrestrial broadcast (DMB-TH) and china mobile digital multimedia broadcast used on a handheld device, and a DMB-TH terminal or a CMMB terminal which adopt the method. The method comprises the steps of receiving and transporting, wherein the receiving step is characterized in that DMB-TH or CMMB signals are not only received, but also transported to a MPEG-2TS transport stream including a video steam, a video stream, or other data objects, or a data stream including a video steam, a video stream, or other data objects, the transporting step is characterized in that the feedback MPEG-2TS transport stream including the video stream, the video stream, or other objects, or the data stream including the video stream, the video stream, or other objects, are converted into a format suitable for being transported to an external device and transported to the external device. The DMB-TH terminal or the CMMB terminal comprises an independent power supply, a receiving sub-module, and a communication sub-module, wherein, the communication is a 204 GHz Bluetooth sub-module, so that the adoption of the Bluetooth sub-module enables various information data to be converted by the Bluetooth standard and sent through a wireless device.

A frequency translating bi-directional amplifier (10) for extending radio coverage for digital mobile radio communication devices (200) on a trunked network using a digital modulation scheme, comprising: a field programmable gate array (FPGA) with local controller (CPU) and firmware (22) configured to analyse control channel messages of a downlink control channel and modify the control channel messages of the downlink control channel that contain traffic channel information; and an antenna (12) to transmit the modified control channel messages to the digital mobile radio communication devices (200) in order to change an operating frequency of the digital mobile radio communication devices (200) to use a predetermined set of frequencies that are repeatable by the bi-directional amplifier (10); wherein the operating frequency between the digital mobile radio communication devices (200) and the bi-directional amplifier (10) is different to an operating frequency between a donor base station (300) and the bi-directional amplifier (10),

The invention discloses a method and a device for achieving voice encryption based on the DMR (Digital Mobile Radio) standard. The method comprises steps of sending a first secret key and a second secret key corresponding to a preset encryption type through a PDU signaling, the second secrete key being a secret key generated in accordance with the generation rule agreed by the first key with the other party; sending data burst which carries the encryption type; and sending voice burst which carries voice data encrypted by the second secret key. The invention provides at least two voice encryption methods based on the PDU signaling format in the DMR standard, one is to use the same secret key in all conversations within a period, and the other is to use a different secret key for each conversation, namely, one secret key for one conversation. Therefore, the product safety performance can be improved, and the user experience is improved.

The invention discloses a timing tracking method and apparatus used in a DMR (Digital Mobile Radio) system and is directed to the field of wireless communication technology. The timing tracking apparatus comprises a base-band orthogonal signal difference extractor, a timing deviation extractor, a weight average arithmetic unit and an interpolation corrector. The base-band orthogonal signal difference extractor carries out a digit down conversion processing towards DMR physical layer modulation signals to obtain base-band orthogonal signals I (k) and Q (k). A difference operation and an arc tangent operation are carried out towards the base-band orthogonal signals I (k) and Q (k) to obtain a difference [fai] (k). The timing deviation extractor extracts a timing discrepancy based on [fai] (k) signal characteristics to obtain the timing discrepancy value e (k) of the present signal. The weight average arithmetic unit utilizes a weight value [omega] to carry out a weight average operation towards the extracted timing discrepancy value e (k) and outputs an average value f (k). The interpolation corrector utilizes Kaiser Window and the average value f (k) to carry out an interpolation correction towards the different [fai] (k) to obtain a correction value y (k). According to the timing tracking method and apparatus in the invention, the timing deviation can be accurately estimated and compensated. The invention is suited for the 4CPFSK signal demodulation in the DMR system.

The invention discloses a coding method and device of a digital mobile radio (DMR) system, a storage medium and a digital radio. The coding method comprises the steps: a voice signal is sampled, quantified and coded to form subframes, the subframes comprise a plurality of characteristic parameters, the multiple characteristic parameters comprise the pitch period, line spectrum frequency coefficients, energy and unvoiced or voiced sound discrimination, and the one or more characteristic parameters are obtained through code book quantification; the subframes with the preset number are spliced toform a voice frame; and the voice frame is subjected to forward error correction to obtain a coding frame. Through the technical scheme, coding bits of the characteristic parameters can be compressed, redundant bits of forward error correction can be increased, the noise resistance of coded data can be enhanced, and the voice transmission quality is improved.

A method and apparatus for enabling a radio to track channel timing and support channel scanning A non-leading radio operating on a communications channel, determines a diffusion period during which channel timing is to be propagated from a leading radio to non-leading radios operating on the communications channel. The non-leading radio implements a first scanning pattern during the diffusion period to scan a CT designated channel for a control timing message with a timing signal sent from the leading radio. The first scanning pattern involves scanning the CT designated channel during every other scan interval and scanning non-priority channels and priority channels during scan intervals not used on the CT designated channel.

The invention discloses a voice and data synchronous transmission method at a DMR (digital mobile radio) terminal. In the method, when the DMR communication terminal transmits voice, one super-frame is sent every 360MS, wherein, 48-bit in the middle of the F-frame of each super-frame transfers invalid data (namely an invalid data area); and the 48-bit invalid data area in the middle of the F-frame of each super-frame is used for transferring data or controlling information. The voice and data synchronous transmission method has the beneficial effects that the 48-bit invalid data area of the F-frame is used for transferring the data or controlling the information, thus achieving the voice and data synchronous transmission effect, saving channels which are originally used for transferring the data and improving utilization ratio of the channels.

The invention discloses a voice transmission encryption method of a DMR (digital mobile radio) communication terminal. In the method, a corresponding key table is arranged in a DMR communication terminal sender and a DMR communication terminal receiver; the DMR communication terminal sender uses keys in the key table to encrypt voice information and send the voice information and key index code information; and the DMR communication terminal receiver searches the corresponding keys in the key table to decrypt and play the voice information in accordance with the key index code information. In the method, when the DMR communication terminal converses and sends the voice superframes, a valid data region of 48BIT in F frames is utilized to transfer the key index information; and the keys are updated once per 360ms, so that the keys are updated in real time to preferably realize the confidentiality of the conversation.

A digital radio telephone comprises a radio portion for receiving a radio signal modulated by an encoded digital signal including control information, for demodulating and outputting the encoded digital signal, a control signal processing portion for decoding the demodulated encoded digital signal to obtain the control information, a telephone number information detecting means for detecting whether the decoded control information includes mate telephone number information, a memory for storing the telephone number information, a time information management means for specifying an incoming time of the telephone number information to output a time information, and a memory management means for recording the telephone number information corresponding to the time information into the memory.

An improved method for digitizing bit synchronization for any random signal source comprises the following steps: delaying an inputted signal sequence at intervals, wherein the signal sequence contains at least more than one path of input signals; multiplying the input signals of each path respectively by at least more than one input signals of the local channels within one symbol period, the multiplied output values are accumulated and then averaged to get the average values within the symbol period; comparing the average values of each channel of each path of input signals, and outputting the selected average value of the path with the maximum average value and its corresponding decode; integrating the maximum average value of each path in a preset time window length, and comparing the integral values of each path, then selecting the path with the maximum integral value and outputting its corresponding decode. It can run well under the random signal resource and satisfy the requirement of real conditions, and can further improve the performance deterioration problem of the original Digital Mobile Radio (DMR) bit synchronization method when the noise is large.

The invention provides a DMR mobile station air interface frequency writing method and system, which relate to the field of intercom systems, and the air interface frequency writing method approximately modifies an existing DMR air interface protocol to a certain extent to enable the DMR air interface protocol to carry configuration parameters of frequency points or group numbers. Then the consoleof the intercom system carries out frequency point or group number parameter configuration on a plurality of handsets in the system by using the modified DMR air interface protocol through the cluster base station, thereby realizing the purpose of carrying out air interface frequency writing on the handsets in a remote and wireless mode.

The invention discloses an anti-noise digital mobile radio signal transmission method and relates to a hybrid framing modulation scheme of the time domain and the frequency domain. Due to the bit interleaved coded modulation mode, the training sequence optimization design, the signal generating scheme and the signal selection method of the anti-noise digital mobile radio signal transmission method, OFDM signals can be processed and recovered at a receiver end easily to obtain original signals of the OFDM signals, and the method has the advantages of being low in peak average power rate, short in synchronization time, resistant to channel fading, multiple in controllable service and the like.