The transmitting device multi-frequency radio system

 

(57) Abstract:

The invention relates to telecommunication systems. The transmitting device multi-channel radio system includes a section of generating a clock signal for receiving the control signal selecting a predetermined bandwidth, multiplexing section, a lowpass filter, a digital to analog Converter, the switch. Technical result achieved is the reduction of energy consumption, as well as signal filtering extended range multi-frequency system using a single low pass filter and a variable speed control sampling when converting filtered at the lower frequencies of the digital signal to an analog signal. 6 C.p. f-crystals, 2 Il.

1. The technical field to which the invention relates

The present invention relates mainly to the communication system, and more particularly to transmitting radio communications device, providing plenty of bandwidth frequencies.

2. Art

Modern digital radio system primarily developed to support voice communication, which can be provided in the same frequency band,exurban. However, in the digital communication system of the next generation information of the subscriber can be changed, including data, video and multimedia services in addition to voice service. Accordingly, for efficient use of the limited available frequency bands and the empowerment of the subscriber you want a new system with a variety of bandwidths, frequencies, able to effectively use the frequency resources, in which one system (for example, mobile and fixed radio installation) provides a set of frequency bandwidths, so that a narrower bandwidth can be allocated to services that use a lower baud rate and wider bandwidth can be allocated to services that use a higher baud rate.

In General, digital radio system must provide features multiple bandwidths, frequencies, so that in addition to voice service to provide the service data with the changing information and speed information transfer. In particular, to ensure adequate capacity and flexible service in the communication system of the type of multiple access is Ohm bandwidth of frequencies.

In Fig. 1 shows the structure of a transmission device capable of providing multiple bandwidths based on the digital communication system of the unitary frequency band of the modulating signals in accordance with the prototype. Section 111 of source coding compresses the information in the form of sound, data or video signals entered by the service subscriber. Sections 112 and 113 of channel coding to encode the output signals of section 111 of source coding with the goal of minimizing errors bitwise transmission during radio communication. In each of the sections 112 and 113 of channel coding uses a different mode of channel coding, respectively; one section 112 of channel coding is a convolutional encoder, and the other section 113 of channel coding is turbocodes, and turbocodes sequentially connected to the encoder reed-Solomon and convolutional encoder. Using two sections 112, 113 channel coding, you can choose the mode of channel coding, based on the subscriber's service and the required level of service quality. Accordingly, any of the sections 112, 113 channel coding can be used in accordance with the subscriber's service and the required level kachestva only one convolutional encoder, while in the case where maintenance is required to maintain higher quality data, use section 113 of channel coding, series connected with the encoder reed-Solomon and convolutional encoder.

The multiplexer 114 selects the output signals of section 112 of channel coding or section 113 of channel coding, using the control signal of the controller (not shown). Section 115 performs digital modulation digital modulation of the output signals of the multiplexer 114 in accordance with the characteristics of the digital radio system. For example, in the case of system MDCRC-PP, section 115 performs digital modulation broadening and modulation data (type two-position or four-position phase manipulation; DFM/CFM).

The output signal of the multiplexer extended to any one of the defined bandwidth among multiple bandwidths, depending on the type of service of the subscriber in section 115 of the digital modulation, and information relating to spread spectrum, passes through the corresponding filter 116, 117, 118 of the lower frequencies through the switching section (not shown) to improve the efficiency of bandwidth and reduce intersymbol interfer the lowering uses a number of filters 116, 117, 118 of the lower frequencies, with varying Polo the actual bandwidth of frequencies and bystrodeistviya. Each low pass filter comprises a digital filter with finite impulse response exclusively to maximizing the efficiency of the bandwidth of frequencies, or a digital filter with finite impulse response pulse shaping for maximising the efficiency of the bandwidth of frequencies and reduce intersymbol interference. As a digital filter with finite impulse response pulse shaping is most commonly used filter is a root raised cosine.

D / a Converter 119 converts each of the digital signals that are filtered in filters 116, 117, 118 of the lower frequencies into analog signals. D / a Converter 119 must have a sampling rate that enables the signal conversion, extended by the maximum bandwidth of the multiple bandwidths system, the analog signal. Section 120 radiochem filters the output signals of the d / a Converter 119 between the bandwidth of the intermediate frequency and bandwidth of the radio frequency and uselimit prior art, has some shortcomings. First as to provide a variety of bandwidths, frequencies used by a number of digital low-pass filters (or filter pulse shaping), for system (mobile or stationary communication systems) require additional power, and reducing the size of the system becomes more difficult; second, for rapid sampling when the sampling signal, advanced on the bandwidth that is different from the maximum bandwidth, require excessive additional capacity; and third, the presence of a certain number of required digital to analog converters makes the reduction of the size of the system more difficult.

The invention

The present invention overcomes the disadvantages of the known prior art, by solving the following two problems. The first task is to provide a transmitting device that can reduce the energy consumption and consequently reduce the size of the radio system, providing plenty of bandwidth frequencies.

Another objective of the present invention is the provision of a transmitting device capable of filtering SR is the sampling rate when converting filtered at the lower frequencies of the digital signal to an analog signal.

To solve the above problems, according to the present invention the transmitting device multi-frequency radio system that provides a variety of bandwidths, frequencies, contains: section generating a clock signal for receiving the control signal selecting a predetermined bandwidth, and then generating a clock signal having a frequency proportional to a predetermined bandwidth; a multiplexing section for the introduction of the zero signal, modulated with the expansion of the spectrum in the bandwidth selected in accordance with the control signal to select a predetermined bandwidth, for the formation of a signal with oversampling; a lowpass filter for receiving the clock signal and to filter the lower frequencies of the output signal of the multiplexing section; a digital / analogue Converter for receiving the clock signal and then convert the output signal of the lowpass filter in the analog signal with the frequency of the clock signal; and a switch for receiving the control signal of the choice of bandwidth and then switching the output signal digital to analogue Converter on me.

List of drawings

The above and other objectives, features and advantages of the present invention are evident from the following detailed description made in conjunction with the attached drawings, in which:

Fig. 1 is a diagram of a transmitting device of a wireless system with multiple bandwidths, frequencies, in accordance with the prototype;

Fig. 2 is a diagram of a transmitting device of a wireless system with multiple bandwidths, frequencies, in accordance with the present invention.

Further details are disclosed preferred embodiments of the present invention, with reference to the accompanying drawings, in which same or similar elements in different drawings are denoted by the same reference position. A detailed description of known functions and configurations are omitted as not relevant to the essence of the present invention.

In Fig. 2 shows that the section 211 of source coding compresses the information in the form of sound, data or video signals entered by the subscriber's service. Sections 212 and 213 of channel coding to encode the output signals of section 211 of source coding with the goal of minimizing errors bitwise transmission during radiosvjaz the bottom section 212 of channel coding is a convolutional encoder, and the other section 213 of channel coding is turbocodes, and turbocodes sequentially connected to the encoder reed-Solomon and convolutional encoder. Using two sections 212, 213 channel coding, you can choose the mode of channel coding depending on the service subscriber and the desired level of service quality. For example, in the case of voice service used section 212 of channel coding, consisting of only one convolutional encoder, while in the case when you want a higher quality of service data used section 213 of channel coding, which sequentially connects to the encoder reed-Solomon and convolutional encoder.

The multiplier 214 selects the output signals of section 212 of channel coding or section 213 of channel coding, using the control signal of the controller (not shown). Section 215 performs digital modulation digital modulation of the output signals of the multiplexer 214 in accordance with the characteristics of the digital radio system. For example, in the case of communication systems MDCRC-PP, section 215 performs digital modulation broadening and modulation data (type FMD, CFM or similar modulation).

The second multiplexer 218 is applied to the output signal of the digital modulator 218 and generator 216 zeros, and is applied with the same clock signal as the clock signal supplied to the generator 216 zeros, thereby introducing a zero in the output signals of the digital modulator 218. The same clock signal that is injected into the generator 216 zeros and the second multiplexer 218 is applied to the filter 219 lowpass filter 219 filters the low-frequency bandwidth from the output of the multiplexer 218.

The clock signal is also supplied to d / a Converter 220 and the inverter 220 converts the digital signal obtained by filtering the low-frequency bandwidth in the analog signal. At this time, the d / a Converter 220 must have a sampling rate that enables the signal conversion, advanced to select which of 217, the output signal of the digital to analog Converter 220 is transferred to the section 225, 226, 227 intermediate frequency switch 222. Section 225, 226, 227 intermediate frequency filters low-pass bandwidth of the intermediate frequency among the entered signals.

Linear amplifier 228 power linearly amplifies the output signals of low-pass filters the intermediate frequency. Section 229 radiochem mixes the output signals of the linear amplifier 228 power with a frequency of subcalibre for the formation of radio frequency filters and transmits the radio signal via the antenna 230. Generator 223 clock signal generates the clock signal at the speed of expansion of the wide bandwidth of the multiple bandwidths provided by the system. The output signal generator 223 synchronizing signal is supplied to the divider 224 clock signal for the formation of a timing signal, with the objective of maintaining a different bandwidth, which is associated with integer ticks.

The third multiplexer 221 selects any one of the synchronizing signals from the output of the generator 223 clock signal and the divider 224 clock signal in accordance with driving the, the Torah multiplexer 218, a filter 219 lower frequencies and d / a Converter 220.

Below is a description of the operation of the transmitting device according to the present invention, however, the description of the section 211 of source coding, section 212 of the channel coding section 213 of channel coding, a multiplexer 214, section 215 of the digital modulation section 229 radiochem and antenna 230 is omitted because they are already above in the section "prior art". The following description refers to the system with multiple bandwidths, providing n bandwidth frequencies B1, B2,...,BN in the same system, but the invention is not limited to systems of this type.

In a digital communication system, bandwidth B1, B2,...,BN are distributed in the form of integers, sets the narrowest bandwidth B1. For example, if B1 is a 5M, B2 corresponds to 10M. The coefficients RS1, RS2, .., RSNexpansion of the range meet the above bandwidths B1,B2,...,BN, respectively. The coefficients of expansion of the range are integers sets the low expansion coefficient, RS1. For example, RS2corresponds to 2RS1. In the case of systems Mdcli similar modulation and modulation extensions. Modulation of the expansion is an expansion in a certain bandwidth from a variety of bandwidth expansion in accordance with the subscriber's service or speed of information transmission. The second multiplexer 218 and generator 216 zeros perform oversampling of the signal, be inserted in the digital low pass filter or low pass filter pulse shaping 219. The oversampling of the signal input to the lowpass filter, allows to increase the precision of the analog signal converted by the d / a Converter 220.

Digital filter 219 low-pass (or low pass filter pulse shaping) synthesizes the coefficients from the conduct and orders of abstraction, which determine the impulse response in the time range of the filter in accordance with the required technical characteristics of the filter (frequency bandwidth, the reference frequency and the insertion attenuation of the transmission and transfer in the core of the band), with the aim of implementing a digital filter with finite impulse response. Where the system provides multiple bandwidths B1, B2,...,BN frequencies, technical characteristics of the filter 219 lower frequencies identically the characteristics and complexity of the filter, regardless of the multiple bandwidths, the coefficient of discharge and the order lead filter should be designed identically. Although the coefficient of discharge and the order lead filter set regardless of the bandwidth, the performance of the filter must be different from the bandwidth, since the bandwidth is determined depending on the performance of the filter 219 lower frequency, i.e. the frequency of the clock signal supplied to the filter 219 lower frequencies.

And coefficient of discharge, and order lead filter 219, which is developed using functions of integer periods of time bandwidths B1, B2, . ..,BN and the coefficients RS1, RS2,.., RSNexpansion of bandwidth are fixed. The following describes the operation of the filter 219, coinciding with the expansion coefficient of multiple bandwidths.

Generator 219 zeros specifies the number of zeros entered in accordance with the frequency of the oversampling, to perform oversampling of the signal input to the filter 219 lower frequencies. After determining the amount subject to the introduction of zeros, generator 216 zeros sequentially generates these zeros. The multiplexer 218 is avatele introduces zeros from the output of the generator 216 zeros in the output signal of the digital modulator 215, and outputs the resulting signal. In General cases, for frequency oversampling use the four-factor RS1, RS2,..., RSNexpansion of bandwidth. For example, in the case of fourfold oversampling, generator 216 zeros consistently introduces triple zero (000) between the output bits of the digital modulator 215 through the multiplexer 218 to output a fourfold oversampling filter 219 lower frequencies. The number of input zeros, i.e., upsampling, controls the control signal selecting the bandwidth coming from the controller (not shown) of the system, and a control select signal bandwidth is also used as a control signal to the divider 224 clock signal and switch 222.

Generator 223 clock signal generates a clock signal with a frequency oversampling ratio RS1, RS2,..., RSNexpansion of the wide bandwidth of the multiple bandwidths provided by the system MDCRC sections with plenty of bandwidth. The divider 224 clock signal is another clock signal to provide the other band proposin astate clock signal divider 224 clock signal and the required number of divisors is equal to the number of multiple bandwidths, provide system MDCRC sections with plenty of bandwidth. For example, in the case of system MDCRC-PP, offering three bandwidths B1, B2 and B3 frequencies (the maximum bandwidth is B3), the required number of dividers 224 clock signal is two, and the frequency of the outgoing clock signal is determined in accordance with an integer ratio between the bandwidths B1, B2 and B3 (for example, B3 is the eightfold B1, B2 - four-B1). In line with this, goes the clock signal generator 223 clock signal, which is used in the broadest bandwidth B3, shares in respect of 1/8 bandwidth B1, or in relation to 1/4 for bandwidth B2. The multiplexer 221 receives the control signal 217 choice of bandwidth, and consequently selects one clock signal from the output clock signal generator 223 clock signal and the divider 224 clock signal, and supplies it to the multiplexer 218, a filter 219 lowpass digital to analog Converter 220 and the generator 216 zeros.

Information in the subscriber bandwidth, the selected control signal selection POI Converter 220 through the filter 219 lower frequencies. For digital to analog Converter 220, an inverter 220 is entered clock signal, which is supplied from generator 223 clock signal when the bandwidth is very wide, or comes from a generator 224 clock signal when the bandwidth is not very wide. Therefore, the performance of digital to analog Converter 220 is not fixed at the maximum frequency clock signal, and changes in response to the selected bandwidth. In other words, if the frequency of the clock signal related to the selected bandwidth, low frequency clock signal that is applied to digital to analog Converter 220, is also low. Accordingly, for a digital to analog Converter 220 can reduce the energy consumption compared to the digital to analog conversion on the frequency of the clock signal, the corresponding maximum bandwidth, regardless of the bandwidth. Coming from digital to analogue Converter 220, the signal supplied to the switch 222 to switch on the circuit intermediate frequency and radio frequency in response to the selected bandwidth, since the filter and zavisimosti from the selected bandwidth. The switch 222 operates a control select signal bandwidth and is provided with the switching of the output signals to analog Converter 220 to the circuit intermediate frequency bandwidth of sections 225, 226, 227 intermediate frequency bandwidths. The signal that has undergone filtering in the filter intermediate frequency is amplified in a linear amplifier 228 power is filtered by the radio frequency section 229 radiochem and transmitted through the antenna 230.

Therefore, the present invention allows to reduce energy consumption in the lowpass filter transmission in the frequency band of the modulating signals and digital-to-analogue Converter. In addition, the present invention can provide a lot of bandwidth through a lowpass filter and a digital to analogue Converter. The size of the system also can be reduced.

Although this invention has been disclosed for example, the preferred variant implementation, it is obvious that the invention is not limited to this embodiment but encompasses different ways, not beyond the nature and scope of the invention described in the claims.

2. The transmitting device under item 1, in which the section generalista synchronization for the wide bandwidth of frequencies from a variety of bandwidths, frequencies, the divider clock signal for dividing the signal fast synchronization, to form a timing signal corresponding to each one of the multiple bandwidths, frequencies, and the second multiplexer for receiving the control signal select bandwidth and thereby to select the desired clock signal from the clock generator signal or the clock signal coming from the divider clock signal.

3. The transmitting device under item 1, in which the multiplexer section contains the generator of zeros to generate the required number of zeros in accordance with the control signal of the choice of bandwidth, and the first multiplexer for receiving the clock signal from the second multiplexer, along with a control select signal bandwidth, and then the introduction of generated zeros in the signal, modulated with the expansion of the range.

4. The transmitting device according to p. 3, in which the generator zeros generates increased the number of zeros for a wider bandwidth.

5. The transmitting device according to p. 4, in which the first multiplexer sequentially introduces generichow">

6. The transmitting device under item 1, in which the low pass filter is a filter pulse shaping.

7. The transmitting device under item 1, in which the low pass filter is a digital filter with finite impulse response.

 

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