JPH0575559A - Transmitting device - Google Patents

Abstract

PURPOSE:To ensure a stable modulating operation with a compact transmitting device which contains a cross connection means with high follow-up performance. CONSTITUTION:The digital modulators 11-1n input the signals of (n) channels and modulate these input signals through the digital signal processing. A digital matrix switch 2 decides a path by a circuit control signal and outputs the signals to the transmission lines 71-7m. The D/A converters 311-31k... 3m1-3mk convert the outputs of the switch 2 into the analog signals. Then the frequency converters 41-4m convert the analog signals into the frequencies assigned to the channels of the lines 71-7m respectively and synthesizes these frequencies to output them to the corresponding transmission lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a wireless communication transmitter.

[0002]

2. Description of the Related Art FIG. 5 is a block diagram of a conventional transmitter.

Conventionally, a transmission apparatus has a configuration as shown in FIG. 5 when it has a cross-connect means for allocating lines. In FIG. 5, the n-channel signal modulated by the analog modulator 110 is switched in the transmission path by switching the path of the input signal at the intermediate frequency (IF) stage using the analog matrix switch 120 configured based on analog elements. Had been assigned. At this time, the intermediate frequency of the modulated wave is as shown in FIG.
The PLL oscillator 100 is individually prepared for switching based on a control signal, or n local oscillators are used and the n local oscillators are selected by a switch to perform switching.

[0004]

However, in such a conventional transmitter, when the cross-connect means is provided, interference characteristics such as interference between adjacent channels and other root interference are important, and the analog matrix switch is used. The conventional configuration requires sufficient isolation between signals to prevent interference, but it is difficult to shield the switches sufficiently, and the size increases, so the size is reduced. There was a problem that I could not do.

On the other hand, in the analog modulator, when a fixed oscillator is used to switch the intermediate frequency, the scale of the hardware is large and the cost is high, and it is difficult to switch in synchronization with the data signal, and even when a PLL oscillator is used. There is a problem in that the tracking is slow and the frequency fluctuates under the influence of the output.

The present invention solves the above problems.
An object of the present invention is to provide a transmission device having a cross-connecting means, small in size, good in followability, and capable of stable modulation operation.

[0007]

According to the present invention, there is provided a transmitting apparatus for modulating a signal of an integer n channel of 1 or more and allocating it to a transmission path of an integer m of 1 or more for transmission.
Channel signals are input respectively, and n digital modulators that modulate the input signals by digital signal processing, and the outputs of the n digital modulators based on the input line control signal are output from the m digital modulators. A digital matrix switch for deciding a path to be assigned to the transmission path and outputting through the decided path, and an integer k channel of n or less assigned to each of the m transmission paths from the digital matrix switch. M × k digital-to-analog converters for converting the output signals into analog signals, and the outputs of the m × k digital-to-analog converters are input to each group, and each channel of each of the m transmission lines is input. And m frequency conversion circuits for converting the frequency to the frequency assigned to the above, synthesizing, and outputting to the corresponding transmission line.

The present invention also includes n parallel-serial converters which are inserted between the n digital modulators and the digital matrix switch to convert the outputs of the n digital modulators into serial signals. Based on the line control signal, the digital matrix switch determines paths for allocating the outputs of the n parallel-serial converters to the m transmission lines, and the n parallel paths are output via the determined paths. Means for outputting the output of the serial converter, inserted between the digital matrix switch and the m × k digital-analog converters for each of the m transmission lines from the digital matrix switch. The output signals of the assigned k integers of n or less are converted into parallel signals, respectively, and the above m × k pieces are converted. Digital analog converters, each of which has m sets of k serial-parallel converters.

[0009]

The n digital modulators respectively input n channel signals, and modulate the input signals by digital signal processing. The digital matrix switch uses n digital modulators based on the input line control signals. The path to which the output of is assigned to the m transmission lines is determined, and the output is output via the determined path. The m × k digital-to-analog converters are integer k less than or equal to n assigned to each of the m transmission lines from the digital matrix switch.
Each of the channel output signals is converted into an analog signal. The m frequency conversion circuits input the outputs of m × k digital-analog converters for each set, convert the frequencies into the frequencies assigned to the respective channels of the m transmission lines, synthesize them, and output them to the corresponding transmission lines. Output.

As described above, it is possible to carry out a stable modulation operation having the cross-connecting means, having a small size and good followability.

[0011]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a transmitting apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram of the digital modulator of the transmitter of the present invention. FIG. 3 is a block diagram of the frequency conversion circuit of the transmitter of the present invention.

1 to 3, the transmitting device of the present invention is characterized in that signals of integer n channels of 1 or more are respectively input and n input signals are modulated by digital signal processing. Digital modulators 1 ₁ to 1
_n and the output of _n digital modulators 1 ₁ to 1 _n based on the input line control signal are integers 1 or more m transmission lines 7
A digital matrix switch 2 that determines a path to be assigned to _{1 to} 7 _m and outputs via the determined path, and m transmission lines 7 ₁ from the digital matrix switch 2
M × k for converting an output signal of an integer k channel of n or less assigned to each of 7 _m to an analog signal
Number of digital-to-analog converters 3 _{11 to} 3 _1k , ..., 3 _{m 1}
3 _mk and m × k digital-to-analog converters 3 _{11 to} 3
Input the output of _1k , ..., 3 _{m1 to} 3 _mk for each group and m
M for converting the frequencies assigned to the respective channels of the book transmission lines 7 _{1 to} 7 _m , synthesizing them, and outputting them to the corresponding transmission lines
The frequency conversion circuits 4 ₁ to 4 _m are provided.

The digital modulator 1 includes a mapping circuit 11, a digital filter 12, and a carrier generator 1.
3, digital multiplier 14 and digital adder 15
including.

Further, the frequency conversion circuit 4 includes a bandpass filter 41 for removing harmonics, a mixer 42, and a local oscillator 4.
3, a hybrid 44 and a channel bandpass filter 45.

The operation of the transmitting apparatus having such a configuration will be described.

1 to 3, the digital modulator 1
Performs modulation calculation of an n-channel input signal. The digital matrix switch 2 inputs the operation result of the output x bits of the digital modulator 1, and outputs data from the output set according to the line control signal. The digital-analog converter 3 digital-analog converts the output data of the digital matrix switch 2 and outputs a modulated wave of the same intermediate frequency. The frequency conversion circuit 4 frequency-converts the output modulated wave of the digital-analog converter 3 into a radio frequency band (RF band) and sends it to each transmission line 7. At this time, a specific carrier frequency is assigned to the frequency conversion circuit 4. As described above, only by allocating the signal obtained from the digital modulator 1 to the digital-analog converter 3 using the digital matrix switch 2, the transmission output can be obtained without performing the switching operation of the analog circuit.

As described above, according to the present embodiment, the input signal is modulated at the same intermediate frequency by using the digital modulator, and the digital signal before being converted into the analog signal is switched by the digital matrix switch to change the transmission line. Allocation is performed, and the output is converted to an analog signal using a digital-to-analog converter to perform frequency conversion, allowing no adjustment without switching the analog circuit and achieving stable modulation with small size and good followability. You can take action.

FIG. 4 is a block diagram of a transmitting apparatus according to the second embodiment of the present invention. In FIG. 4, the parallel-serial converter 5 converts the output from the digital modulator 1 into serial data and then outputs the serial data to the digital matrix switch 2. On the other hand, on the output side of the digital matrix switch 2, the serial-parallel converter 6 reconverts the output of the digital matrix switch 2 into parallel data and outputs it to the digital-analog converter 3. As a result, the circuit scale of the digital matrix switch 2 can be further reduced.

[0019]

As described above, the present invention has an excellent effect that it has a cross-connecting means, is small in size, has good followability, and can perform stable modulation operation. Further, since a digital matrix is used, there is an advantage that crosstalk between signals is reduced.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a transmission device according to a first embodiment of the present invention.

FIG. 2 is a block configuration diagram of a digital modulator of the transmission device according to the first embodiment of the present invention.

FIG. 3 is a block configuration diagram of a frequency conversion circuit of the transmission device according to the first embodiment of the present invention.

FIG. 4 is a block configuration diagram of a transmission device according to a second embodiment of the present invention.

FIG. 5 is a block configuration diagram of a conventional transmission device.

[Explanation of symbols]

1, 1 ₁ to 1 _n Digital modulator 2 Digital matrix switch 3 _{11 to} 3 _1k , 3 _{21 to} 3 _2k , ... 3 _{m 1 to} 3 _mk Digital-analog converter 4, 4 ₁ to 4 _m Frequency conversion circuit 5 ₁ ~ 5 _n parallel-to-serial converter 6 _{11 to} 6 _1k , 6 _{21 to} 62 _2k , ..., 6 _{m 1 to} 6 _mk serial-to-parallel converter 7 _{1 to} 7 _m transmission line 11 mapping circuit 12 digital filter 13 carrier generator 14 digital multiplier 15 Digital adder 41 _{1 to} 41 _k Bandpass filter for removing harmonics 42 _{1 to} 42 _k Mixer 43 ₁ to 43 _k Local oscillator 44 Hybrid 45 Channel bandpass filter 100 _{1 to} 100 _n PLL oscillator or n channel local oscillator 110 ₁ to 110 _n analog modulator 120 analog matrix switch 130 ₁ to 130 DEG _m channel band Pass filter A baseband signal input B line control signal input C digital modulator output D frequency converter input signal (digital-to-analog converter output) E transmission output

Claims (2)

[Claims] 1. A transmission device for performing modulation by a signal of an integer n channel of 1 or more and allocating and transmitting the signal to an integer m number of transmission lines of 1 or more, by inputting each signal of the n channel and performing digital signal processing. The n digital modulators that modulate the input signal and the paths that allocate the outputs of the n digital modulators to the m transmission lines are determined based on the input line control signal. A digital matrix switch for outputting via a path, and m × k for converting an output signal of an integer k channel of n or less assigned to each of the m transmission lines from the digital matrix switch into an analog signal. Number of digital analog-to-analog converters and the output of the m × k digital-to-analog converters for each group, and the above-mentioned m transmission lines are input. Transmission apparatus being characterized in that a m number of frequency conversion circuit for outputting the transmission line is converted to a frequency assigned to each channel of each corresponding synthesized. 2. A parallel serial-to-serial converter, which is inserted between the n digital modulators and the digital matrix switch and converts the outputs of the n digital modulators into serial signals, respectively. The digital matrix switch determines a path for allocating the outputs of the n parallel-to-serial converters to the m transmission lines based on the line control signal, and the paths of the n parallel-to-serial converters are determined through the determined paths. Means for outputting an output, inserted between the digital matrix switch and the m × k digital-to-analog converters and assigned to each of the m transmission lines from the digital matrix switch. The output signals of the following integer k channels are converted into parallel signals, respectively, and the above m × k digital signals are converted. The transmitter according to claim 1, further comprising m sets of k serial-parallel converters for outputting to the analog converter.