JP2920221B2 - Base station transmitter - 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 base station transmitting apparatus for wireless communication. In particular, the present invention relates to a base station transmitting apparatus that modulates and transmits an n-channel baseband signal to m transmission paths of different frequencies.

[0002]

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

Conventionally, when a base station transmitting apparatus has cross-connect means for allocating a line, it has a configuration as shown in FIG. That is, in FIG. 5, the matrix switch 53 configured based on the analog switch element is a modulated n-channel baseband signal A _1.
Was sent performs an assignment for the transmission path 7 ₁ to _7-m of the m mutually different frequencies by switching the path to A _n at an intermediate frequency (IF) stage. In this case, the intermediate frequency of the modulated wave is set to each of the analog modulators 51 ₁ to 51 _{1 as} shown in FIG.
Individually provided PLL oscillator 52 ₁ to 52 _n to 51 _n, selects the local oscillator with the or switching the frequency, or the switch is provided an n-number of local oscillator according to the frequency control signal G ₁ ~G _n Switching was performed by this.

[0004]

However, in such a conventional base station transmitting apparatus, when cross-connect means is provided, interference characteristics such as interference between adjacent channels and interference with other routes are important, and the matrix switch In the conventional configuration using, it is necessary to provide sufficient isolation between signals in order to reduce interference.However, it is difficult to shield between switches sufficiently, and the size increases. There was a problem that could not be converted. On the other hand, in the modulator, when switching the intermediate frequency using a fixed oscillator, it is difficult to switch in synchronization with a data signal, and when using a PLL oscillator, it is difficult to switch the frequency instantaneously. There was a point.

The present invention solves the above problems,
An object of the present invention is to provide a small, flexible, and non-adjustable base station transmitting apparatus having cross-connect means.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a base station transmitting apparatus for modulating a baseband signal of one or more integer n channels and allocating the modulated signal to one or more integer m transmission lines for transmission. , The n-channel baseband signal and the corresponding frequency control signal are input, and the carrier frequencies determined by the frequency control signal are digitally processed and modulated by the baseband signal into n digital signals. A modulator, and a digital matrix switch that determines paths for allocating the outputs of the n digital modulators to the m transmission paths based on the input line control signals, and outputs the respective paths via the determined paths. For each of the modulation signals for k channels of integers less than n output from this digital matrix switch, Type, by performing respective signal synthesis and digital-to-analog conversion, characterized in that a m number of signal combining circuit to output to the transmission path of the m pieces.

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. Wherein 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 outputs respective paths via the determined paths. And a parallel signal of the same bit as the output of the digital modulator for each k-channel modulated signal output between the digital matrix switch and the m signal synthesizing circuits and output by the digital matrix switch. M sets of k series which are re-converted and output to the m signal synthesizing circuits, respectively. It may comprise a Ruparareru converter.

[0008]

The n digital modulators receive an n-channel baseband signal and a corresponding frequency control signal, and perform digital signal processing on the carrier frequencies determined by the frequency control signal using the baseband signal. Modulation. The digital matrix switch determines paths for allocating the outputs of the n digital modulators to the m transmission paths based on the line control signals, and outputs the paths via the determined paths. m
The signal synthesizing circuits respectively input the modulated signals for k integer channels of n or less output from the digital matrix switch, perform signal synthesis and digital-to-analog conversion, and output the signals to m transmission paths.

As described above, a cross-connect means is provided, which is small in size, highly flexible, and free from adjustment.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a base station transmitting apparatus according to one embodiment of the present invention. FIG. 2 is a block diagram of the digital modulator of the base station transmitting apparatus according to the present invention. FIG. 3 is a block diagram of a signal combining circuit of the base station transmitting apparatus according to the present invention.

1 to 3, the base station transmitting apparatus according to the present invention is characterized in that n-channel baseband signals A _{1 to An} and a frequency control signal C corresponding thereto.
Enter a, and n digital modulators 1 ₁ to 1 _n for performing modulation by a respective digital signal processing of the carrier frequency by the baseband signal A ₁ to A _n which are respectively determined by the frequency control signal C, input The paths for allocating the output modulation signals D _{1 to} D _n of the _n digital modulators ₁₁ to _{1 n} to the m transmission lines ₁ to m are determined based on the line control signal B to be transmitted, and the determined paths are assigned. , E _{m1 to} E _mk , respectively, and outputs a digital matrix switch 2 that outputs each of the modulated signals E _{11 to} E _1k ,. m to be output to the transmission path 7 ₁ to _7-m of the m by performing the analog conversion, respectively
In that a number of signal combining circuit 3 ₁ to 3 _m.

[0012] Each digital modulator ₁ 1 to 1 _n has a mapping circuit 11, the digital filter 12
, Carrier generator 13 and frequency offset circuit 14
, A digital multiplier 15 and a digital adder 16.

The signal synthesizing circuits 3 _{1 to} 3 _{m further} include a k-input full adder 31, a digital-to-analog converter 32, a band-pass filter 33 for removing high frequency, a mixer 34, a local oscillator 35, And a band-pass filter 36 for the channel.

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

[0015] 1 to 3, the input signals of the n channels are input to the digital modulator ₁ 1 to 1 _n. Digital modulator 1 ₁ to 1 _n, the base of the difference between the carrier frequency generated by the frequency control signal C frequency and set by the digital modulator 1 ₁ to 1 _n of the carrier generator 13 for inputting the frequency offset circuit 14 The band signal is given as phase rotation. Further, a carrier generator 13, a digital multiplier 15, and a digital adder 16 perform quadrature modulation operation on the output of the frequency offset circuit 14, and perform x-bit modulation signals D _{1 to} D _n to which frequencies are assigned by digital signal processing. Is output. The digital matrix switch 2 outputs x-bit modulated signals D _{1 to} D _1
n, and outputs modulated signals E _{11 to} E _1k ,..., E _{m1 to} E _mk from the output set based on the line control signal B. Signal combining circuit 3 ₁ to 3 _m is the modulation signal _{E 11 ~E 1k, ..., E} m1
ＥE _mk , a signal is synthesized by a k-input full adder 31, converted into an analog signal by a digital-to-analog converter 32, and a harmonic is removed by a band-pass filter 33 for removing harmonics. 35, and sends the frequency-converted by a mixer 34 and bandpass filter 36 for channel to the transmission path 7 ₁ to _7-m.

FIG. 4 is a block diagram of a base station transmitting apparatus according to another embodiment of the present invention. In FIG. 4, 4 ₁ ~4 _n is parallel-serial converter and _{5 11 ~5 1k, ..., 5} m1 ~5
_mk indicates a parallel-serial converter. Here, the parallel-serial converters 4 ₁ to 4 _n are digital modulators ₁₁ to 1.
and it outputs the digital matrix switch 2 to output modulated signal D ₁ to D _n from _n after conversion to serial data. On the other hand, the serial-parallel converters 5 _{11 to} 5 _1k,.
m1 to 5 _mk converts the serial data output of the digital matrix switch 2 to the parallel data modulated signal E
_{11 to} E _1k ,..., E _{m1 to} E _mk are output to the signal synthesis circuit 3.

By providing the parallel-serial converter and the serial-parallel converter as described above, the present embodiment can reduce the circuit size of the digital matrix switch.

[0018]

As described above, the present invention has an excellent effect that it has a cross-connect means, is small in size, has high flexibility, and can be adjusted without adjustment.

[Brief description of the drawings]

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

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

FIG. 3 is a block diagram of a signal combining circuit of the base station transmitting apparatus of the present invention.

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

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

[Explanation of symbols]

1 ₁ to 1 _n digital modulator 2 digital matrix switch 3 ₁ to 3 _n signal combining circuit 4 ₁ to 4 _n parallel serial converter _{5 11 ~5 1k, ..., 5} m1 ~5 mk serial-parallel converter 7 _{1-7 m} transmission line 51 _{1 to} 51 _n analog modulator 52 _{1 to} 52 _n PLL oscillator (or n-channel local oscillator) 53 analog matrix switch 54 _{1 to} 54 band filter for _m channel A baseband signal B, F line control signal C , G _{1 to} G _n frequency control signals D, E modulation signals

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04B 7/24-7/26 102 H04Q 7/00-7/38

Claims (2)

(57) [Claims] 1. A base station transmitting apparatus for modulating with a baseband signal of one or more integer n channels and allocating the modulated signal to one or more integer m transmission paths and transmitting the modulated signal, And a frequency control signal corresponding thereto, and n digital modulators for modulating the carrier frequencies respectively determined by the frequency control signal by digital signal processing using the baseband signal, respectively; A path for allocating the outputs of the n digital modulators to the m transmission paths based on the signals is determined, and a digital matrix switch that outputs the signals via the determined paths, and n that is output from the digital matrix switch. The following integer k channels of modulated signals are input respectively, and signal synthesis and A base station transmitting apparatus comprising: m signal synthesizing circuits for performing digital-to-analog conversion and outputting the signals to the m transmission paths. 2. The apparatus according to claim 1, further comprising: n parallel-serial converters inserted between the n digital modulators and the digital matrix switch to convert the outputs of the n digital modulators into serial signals. The digital matrix switch includes means for deciding paths for allocating the outputs of the n parallel-serial converters to the m transmission paths based on the line control signals and outputting the paths via the decided paths, respectively. Each k-channel modulated signal output from the digital matrix switch inserted between the matrix switch and the m signal synthesizing circuits is re-converted into a parallel signal having the same bit as the output of the digital modulator. M sets of k serial / parallel converters respectively output to the m signal synthesizing circuits. The base station transmission apparatus according to claim 1, further comprising a vessel.