JP2835658B2 - Transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a transmission apparatus for wireless communication.

[0002]

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

Conventionally, when a transmitting apparatus has cross-connect means for allocating a line, it has a configuration as shown in FIG. In FIG. 5, an n-channel signal modulated by an analog modulator 110 is switched on an intermediate frequency (IF) stage by switching an input signal path at an intermediate frequency (IF) stage using an analog matrix switch 120 configured based on analog elements. Allocation was done. At this time, the intermediate frequency of the modulated wave is set at each analog modulator 110 as shown in FIG.
The switching is performed by individually preparing the PLL oscillator 100 and switching based on the control signal, or by using n local oscillators and selecting the n local oscillators with a switch.

[0004]

However, in such a conventional transmitting apparatus, when cross-connect means is provided, interference characteristics such as interference between adjacent channels and interference from other routes are important, and an analog matrix switch is used. In the conventional configuration, it was necessary to provide sufficient isolation between signals in order to prevent interference, but it was difficult to adequately shield between the switches, and the size was increased due to the increase in size. There was a problem that could not be done.

On the other hand, in the analog modulator, when the intermediate frequency is switched using a fixed oscillator, the scale of hardware is large and expensive, and it is difficult to switch in synchronization with a data signal. There is a problem that the tracking is slow and the frequency fluctuates due to the influence of the output.

The present invention solves the above problems,
It is an object of the present invention to provide a transmitting apparatus which has a cross-connect means and which is small in size, has good tracking, and can perform a stable modulation operation.

[0007]

According to the present invention, there is provided a transmitting apparatus for modulating a signal of one or more integer n channels and allocating the modulated signal to one or more integer m transmission paths for transmission.
Each of the channel signals is input, and n digital modulators for modulating the input signals by digital signal processing, and the outputs of the n digital modulators based on the input line control signals are output from the m digital modulators. A digital matrix switch that determines a path to be assigned to the transmission path and outputs the signal through the determined path; and an integer k or less of n or less channels 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 respective outputs of the m × k digital-to-analog converters for each pair of the m transmission lines And m frequency conversion circuits for converting the frequency to the frequency assigned to the corresponding channel, synthesizing the frequency, and outputting the result to the corresponding transmission path.

Further, the present invention provides n parallel-serial converters which are inserted between the n digital modulators and the digital matrix switch and convert 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-serial converters to the m transmission paths based on the line control signal, and determines the n parallel paths via the determined path. Means for outputting the output of a serial converter, wherein each of the m transmission lines from the digital matrix switch is inserted between the digital matrix switch and the m × k digital-to-analog converters. The output signals of the assigned integer k channels of n or less are converted into parallel signals, and the above m × k signals are converted. And m serial k-parallel converters respectively outputting to the digital-to-analog converters.

[0009]

The n digital modulators input n-channel signals, respectively, and modulate the input signals by digital signal processing. The digital matrix switch uses the n digital modulators based on the input line control signals. Are determined to be allocated to the m transmission paths, and are output via the determined paths. The m × k digital-to-analog converters are integers k or less assigned to each of the m transmission lines from the digital matrix switch.
Each channel output signal is converted into an analog signal. The m frequency conversion circuits input the outputs of the m × k digital-to-analog converters for each group, convert them to the frequencies assigned to each channel of the m transmission lines, synthesize them, and form the corresponding transmission lines. Output.

As described above, it is possible to perform a stable modulation operation having the cross-connect means, and 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 the transmitting apparatus according to the first embodiment of the present invention. FIG. 2 is a block diagram of the digital modulator of the transmitting apparatus according to the present invention. FIG. 3 is a block diagram of the frequency conversion circuit of the transmission device of the present invention.

1 to 3, the transmitting apparatus according to the present invention is characterized in that n or more integer n-channel signals are input, and n signals are modulated by digital signal processing. Digital modulators ₁₁ to 1
_n and the outputs of the n digital modulators 1 ₁ to 1 _n based on the input line control signal are converted into one or more integer m transmission paths 7
A digital matrix switch 2 that determines a path to be assigned to _{1 to} 7 _m and outputs the signal through the determined path, and m transmission paths 7 ₁ from the digital matrix switch 2
M × k where for each to _7-m converts assigned n the output signal of an integer k channels, each analog signal
Number of digital-to-analog converter _{3 11 ~3 1k, ..., 3} m1 ~
3 _mk and m × k digital-to-analog converters 3 _{11 to} 3
_1k , ..., 3 _{m1-3 mk} output is input for each group
M is output to the transmission path is converted into a frequency assigned to each channel of each of the transmission line 7 ₁ to _7-m synthesized corresponding to the present
In that a number of frequency converter 4 ₁ to 4 _m.

The digital modulator 1 comprises a mapping circuit 11, a digital filter 12, 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, a local oscillator 4
3, including a hybrid 44 and a band-pass filter 45 for a channel.

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

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

As described above, in this 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 so that the transmission path is changed. Allocation is performed, the output is converted to an analog signal using a digital-to-analog converter, and frequency conversion is performed. This eliminates the need for switching the analog circuit and eliminates adjustment. Actions can be performed.

FIG. 4 is a block diagram of a transmitting apparatus according to a second embodiment of the present invention. In FIG. 4, a 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 the parallel data to the digital / analog converter 3. Thereby, 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-connect means and is small in size, has a good tracking performance, and can perform a stable modulation operation. Further, since a digital matrix is used, there is an advantage that crosstalk between signals is reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of a transmitting apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a digital modulator of the transmitting apparatus according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a frequency conversion circuit of the transmitting apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram of a transmitting apparatus according to a second embodiment of the present invention.

FIG. 5 is a block diagram of a conventional transmitting apparatus.

[Explanation of symbols]

1, 1 ₁ to 1 _n digital modulator 2 digital matrix switch _{3 11 ~3 1k, 3 21 ~3} 2k, ..., 3 m1 ~3 mk digital-to-analog converter 4, 4 ₁ to 4 _m frequency converting circuit 51 _to 5 _n parallel serial converter _{6 11 ~6 1k, 6 21 ~6} 2k, ..., 6 m1 ~6 mk serial-parallel converter 7 ₁ to _7-m transmission line 11 mapping circuit 12 the digital filter 13 carrier generator 14 digital multiplier Reference Signs List 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04J 1/12 H04B 7/24

Claims (2)

(57) [Claims] 1. A transmitting apparatus that modulates signals with one or more integer n channels and allocates the signals to one or more integer m transmission paths and transmits the signals. The n digital modulators for modulating the input signal and the paths for allocating the outputs of the n digital modulators to the m transmission paths based on the input line control signal are determined. A digital matrix switch for outputting via a path, and an m × k for converting an integer k or less channel output signal from the digital matrix switch assigned to each of the m transmission paths into an analog signal. Digital-to-analog converters and the outputs of the m × k digital-to-analog converters are input for each set, and the m transmission paths 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. The apparatus according to claim 1, further comprising: n parallel-serial converters inserted between the n digital modulators and the digital matrix switch, each converting the output of the n digital modulators into a serial signal. The digital matrix switch determines a path for allocating the outputs of the n parallel-serial converters to the m transmission paths based on the line control signal, and determines the paths of the n parallel-serial converters through the determined paths. Means for outputting an output, wherein n is 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 amplifiers are converted. 2. The transmitting apparatus according to claim 1, further comprising: m sets of k serial / parallel converters for outputting to the analog converter.