JPH05160783A - Base station transmitter - Google Patents

Abstract

PURPOSE:To attain a transmitter with a small size, rich flexibility and requiring no adjustment by providing a cross connect means to the transmitter. CONSTITUTION:n-Sets of digital modulators 1 modulate a carrier frequency depending on a frequency control signal C with a base band signal A through digital signal processing respectively. A digital matrix switch 2 decides paths to allocate the outputs of the digital modulators 1 to m-sets of transmission lines 7 based on a line control signal B and output the result via the decided path respectively. m-sets of signal synthesis circuits 3 implement signal synthesis and D/A conversion to each of k-channels of modulation signals E outputted from a digital matrix switch 2 respectively and output the result to the transmission lines 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used in a base station transmitter for wireless communication. In particular, the present invention relates to a base station transmitter that modulates an n-channel baseband signal onto m transmission lines having different frequencies and sends out the modulated signal.

[0002]

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

Conventionally, a base station transmitter has a configuration as shown in FIG. 5 when it has a cross connect means for allocating lines. 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 the analog modulator 51 _1, as shown in FIG. 5
51 _n are individually provided with PLL oscillators 52 _{1 to} 52 _n and the frequency thereof is switched according to the frequency control signals G _{1 to} G _n , or n local oscillators are provided and the local oscillator is selected by using a switch. It was switching by that.

[0004]

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

The present invention solves the above problems.
It is an object of the present invention to provide a base station transmitter which has a cross-connect means, is small in size, is highly flexible, and can be adjusted without adjustment.

[0006]

According to the present invention, there is provided a base station transmitter which modulates a baseband signal of one or more integer n channels and allocates the modulated signal to m or more integer transmission channels for transmission. , The n-channel baseband signal and the corresponding frequency control signal are input, and the n carrier digital signals are subjected to digital signal processing to modulate the carrier frequencies determined by the frequency control signal. A modulator and a digital matrix switch for determining paths for allocating the outputs of the n digital modulators to the m transmission lines based on the input line control signal and outputting the paths via the determined paths, respectively. For each integer k channel or less modulated signal 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.

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. The digital matrix switch determines means for allocating the outputs of the n parallel-to-serial converters to the m transmission lines based on the line control signal, and outputs means through the determined paths. Each of the k channel modulation signals output from the digital matrix switch and inserted into the digital matrix switch and the m signal combining circuits is converted into a parallel signal of the same bit as the output of the digital modulator. M sets of k series which are re-converted and output to the m signal combining circuits respectively. It may comprise a Ruparareru converter.

[0008]

The n digital modulators input the n-channel baseband signals and the corresponding frequency control signals, and perform the digital signal processing on the carrier frequencies respectively determined by the frequency control signals. To modulate. The digital matrix switch determines the paths that allocate the outputs of the n digital modulators to the m transmission lines based on the line control signal, and outputs the paths through the determined paths. m
The respective signal synthesizing circuits respectively input the modulated signals for the integer k channels less than n output from the digital matrix switch, perform signal synthesizing and digital-analog conversion respectively, and output to m transmission lines.

As described above, the device has the cross-connecting means, is small in size, has high flexibility, and can be adjusted.

[0010]

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

1 to 3, the base station transmitter of the present invention is characterized in that n-channel baseband signals A _{1 to} A _n and a frequency control signal C corresponding thereto are provided.
, And n digital modulators 1 ₁ to 1 _{n for} modulating the carrier frequencies respectively determined by the frequency control signal C by digital signal processing with the baseband signals A _{1 to} A _n , respectively, and Based on the line control signal B, the paths for allocating the output modulation signals D _{1 to} D _n of the _n digital modulators 1 ₁ to _{1 n} to the m transmission lines ₁ to m are determined, and the paths are determined via the determined paths. , And each of the modulated signals E _{11 to} E _1k , ..., E _{m1 to} E _mk for n or less integer channels output by the digital matrix switch 2 are input, respectively, and then combined and digitalized. m to be output to the transmission path 7 ₁ to _7-m of the m by performing the analog conversion, respectively
This is because it is provided with the individual signal synthesizing circuits 3 _{1 to} 3 _m .

Each of the digital modulators 1 ₁ to 1 _n has a mapping circuit 11 and a digital filter 12 respectively.
, Carrier generator 13, and frequency offset circuit 14
And a digital multiplier 15 and a digital adder 16.

Further, each of the signal synthesizing circuits 3 _{1 to} 3 _m has a k-input full adder 31, a digital-analog converter 32, a high-frequency removing bandpass filter 33, a mixer 34, a local oscillator 35, and And a bandpass filter 36 for the channel.

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

1 to 3, n channel input signals are input to digital modulators 1 ₁ to 1 _n , respectively. The digital modulators 1 ₁ to 1 _n are based on the difference between the frequency set by the frequency control signal C input by the frequency offset circuit 14 and the carrier frequency generated by the carrier generator 13 of the digital modulators 1 ₁ to 1 _n. It is given to the band signal as a phase rotation. Further, the carrier generator 13, the digital multiplier 15 and the digital adder 16 perform quadrature modulation operation on the output of the frequency offset circuit 14, and x-bit modulated signals D _{1 to} D _n to which frequencies are assigned by digital signal processing. Is output. The digital matrix switch 2 is an x-bit modulated signal D _{1 to} D.
_n is input and the modulated signals E _{11 to} E _1k , ..., E _{m1 to} Em _mk are output from the output set based on the line control signal B. The signal synthesizing circuits 3 _{1 to} 3 _m are modulated signals E _{11 to} E _1k , ..., E _m1.
~ E _mk is input, the signals are combined by the k-input full adder 31, converted into an analog signal by the digital-analog converter 32, the harmonics are removed by the bandpass filter 33 for removing the harmonics, and the local oscillator is generated. 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 transmitter according to another embodiment of the present invention. In FIG. 4, 4 ₁ to 4 _n are parallel-serial converters and 5 _{11 to} 51 _k , ..., 5 _{m 1 to} 5
_mk indicates a parallel-serial converter. Here, the parallel-serial converters 4 ₁ to 4 _n are digital modulators 1 ₁ 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, serial / parallel converters 5 _{11 to} 5 _1k , ..., 5
_{m1 to} 5 _mk are modulation signals E obtained by converting serial data output from the digital matrix switch 2 into parallel data.
₁₁ ~E _1k, ..., and outputs the E _m1 to E _mk to the signal synthesizing circuit 3.

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

[0018]

As described above, the present invention has the cross connecting means, is small in size, is highly flexible, and has an excellent effect that no adjustment is required.

[Brief description of drawings]

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

FIG. 2 is a block configuration diagram of a digital modulator of the base station transmitter of the present invention.

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

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

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

[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 to} 5 _{1 k} , ... 5 _{m 1 to} 5 _mk Serial / parallel converter 7 _{1 to} 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 signal D, E modulation signal

Claims (2)

[Claims] 1. A base station transmitting apparatus for modulating a baseband signal of integer n channels of 1 or more and allocating the modulated signal to transmission channels of integer m of 1 or more, and transmitting the baseband signal of n channels. And a frequency control signal corresponding thereto, and n digital modulators for modulating the carrier frequencies respectively determined by this frequency control signal by digital signal processing by this baseband signal, and the input line control Based on the signal, a digital matrix switch that determines the paths to which the outputs of the n digital modulators are assigned to the m transmission paths, and outputs the paths through the determined paths, and n output from the digital matrix switch Input the following integer k channels for each modulated signal, A base station transmitter, comprising: m signal synthesizing circuits that perform digital-analog conversion respectively and output to the m transmission lines. 2. A parallel 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 includes means for deciding a path for allocating the outputs of the n parallel-serial converters to the m transmission lines based on the line control signal and outputting the paths via the decided paths. It is inserted between the matrix switch and the m number of signal combining circuits, and each k channel of modulation signal output from the digital matrix switch is reconverted into a parallel signal of the same bit as the output of the digital modulator. M sets of k serial-parallel converters to be output to the m signal combining circuits. The base station transmission apparatus according to claim 1, further comprising a vessel.