KR20030090173A - Space-time transmitter having characteristic of time delay - Google Patents

Abstract

PURPOSE: A space-time transmission diversity system having a time delay characteristic is provided so as to be applied to an existing base station system without the necessity of changing equipments in a base station system or installing a new base station to execute a transmission diversity function. CONSTITUTION: A space-time transmission diversity system(200), located between the second amplifier(60) and an RF/IF transceiver(30a), comprises a diversity antenna(12), a Tx filter(22), a delay element(52), and the first amplifier(62). In addition, the space-time transmission diversity system(200) comprises a power distributor(72) connected between the RF/IF transceiver(30a), the delay element(52), and the second amplifier(60) so that the power of an RF signal outputted from the Tx output port of the RF/IF transceiver(30a) can be supplied to the delay element(52) and the second amplifier(60) without being lowered. The delay element(52) is connected to the front end of the first amplifier(62). The input port of the delay element(52) and the input port of the second amplifier(60) are connected to the Tx output port of the RF/IF transceiver(30a). The output port of the delay element(52) is connected to the input port of the first amplifier(62). The output port of the first amplifier(62) is connected to the input port of the Tx filter(22). The output port of the Tx filter(22) is connected with the diversity antenna(12).

Description

SPACE-TIME TRANSMITTER HAVING CHARACTERISTIC OF TIME DELAY}

The present invention relates to a transmit diversity apparatus for increasing forward capacity in a wireless communication system including mobile communication. More specifically, the present invention is a space-time transmit diversity apparatus that can obtain a transmit diversity effect by using a time delay difference between a space between a plurality of transmit antennas and a transmission signal transmitted to each transmit antenna.

In the mobile communication system, since the signal transmitted from the base station is reflected by the terrain of the terrestrial environment, the same signal transmitted from the base station arrives at the mobile station with different delay time through various paths, resulting in waveform distortion. This phenomenon is called multipath, and a Rake receiver is used in a mobile station to improve waveform distortion due to multipath. The rake receiver inputs a multipath signal to a plurality of independent demodulators, and these demodulators perform spectral despreading with spreading codes of time phases corresponding to respective paths, and then symbol synthesize the despreaded multipath signals. The process of playing the received data is performed.

In a mobile communication system, fading is another phenomenon that causes degradation of call quality along with a multi-pass phenomenon. Fading is very closely related to the multipath phenomenon, and various transmission diversity methods have been developed to solve this problem. The main transmit diversity methods developed to date include time diversity, frequency diversity, and spatial diversity.

However, in order to apply various transmission diversity methods to a mobile communication system that is currently used, many base station systems need to be completely replaced. Therefore, the introduction of the transmission diversity method is very economically burdensome for mobile operators. There is a problem.

Accordingly, in order to solve the above-described problem, an object of the present invention is to provide a space-time transmit diversity apparatus and method applicable to a conventional base station system without establishing a base station that performs equipment replacement or transmission diversity function of the base station system. To provide.

Another object of the present invention is to provide a space-time transmit diversity apparatus and method capable of increasing the forward capacity of a base station system by using the space-time transmit diversity apparatus.

1 is a block diagram showing an internal configuration of a mobile communication base station.

2 is a block diagram showing an internal configuration of a mobile communication mobile station.

3 is a conceptual diagram of space-time transmit diversity according to the present invention.

4 is a block diagram schematically showing a transmission structure of a mobile communication base station.

5 is a block diagram schematically illustrating an internal configuration of a space-time transmit diversity base station according to an embodiment of the present invention.

6A is a block diagram schematically illustrating a space-time transmit diversity apparatus according to an embodiment of the present invention.

6B is a block diagram schematically illustrating a space-time transmit diversity apparatus according to another preferred embodiment of the present invention.

In order to achieve the above objects, according to an aspect of the present invention, a space-time transmit diversity base station system, comprising: a plurality of antennas; A plurality of duplexers coupled to the antenna and having at least one Tx input and at least one Rx output; A plurality of amplifiers coupled to the Tx input terminal of the duplexer; At least one time delay element coupled to an input of at least one of said amplifiers; A Tx output terminal is coupled to an input terminal of the time delay element and an input terminal of at least one amplifier not coupled to the time delay element, an Rx input terminal is coupled to an Rx output terminal of the duplexer, and at least one Tx input terminal and at least one Rx At least one transceiver having an output stage; And a modem having a Tx input terminal and an Rx input terminal coupled to the Tx input terminal and the Rx output terminal of the transceiver, respectively. A space-time transmit diversity base station system according to another preferred embodiment of the present invention is provided. A city base station system, comprising: a plurality of antennas; A plurality of duplexers coupled to the antenna and having at least one Tx input and at least one Rx output; At least one time delay element coupled to an input of at least one duplexer of the duplexers; At least one amplifier coupled to a Tx input terminal of at least one duplexer not coupled with the time delay element of the time delay element and the duplexer; At least one transceiver having a Tx output stage coupled to an input of the amplifier, an Rx input coupled to an Rx output stage of the duplexer, and having at least one Tx input stage and at least one Rx output stage; And a modem in which a Tx input terminal and an Rx input terminal are coupled to the Tx input terminal and the Rx output terminal of the transceiver, respectively.

According to still another preferred embodiment of the present invention, there is provided a space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, a transceiver and a modem, comprising: at least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; At least one first amplifier having an output coupled to an input of the Tx filter; And a time delay element having an output end coupled to an input end of the amplifier, wherein an input end of the time delay element is coupled to a Tx output end of the transceiver. According to an example, a space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, an amplifier, a transceiver, and a modem, the apparatus comprising: at least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; And a time delay element having an output end coupled to an input end of the amplifier, wherein an input end of the time delay element is coupled to an output end of the amplifier.

According to still another preferred embodiment of the present invention, there is provided a space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, a transceiver and a modem, comprising: at least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; A time delay element having an output coupled to an input of the amplifier; And an amplifier having an output terminal coupled to an input terminal of the time delay element and a Tx input terminal of the duplexer, wherein the input terminal of the amplifier is coupled to the Tx output terminal of the transceiver. Preferred embodiments of the invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing an internal configuration of a mobile communication base station.

The structure of the current mobile communication system IS-95A / B, CDMA2000, 1xEV-DO, and W-CDMA base station system is composed of three sectors as shown in FIG. Is composed of an antenna 10a, 10b, 10c, 10d or one X-pole 10e antenna. The forward transmission signal transmitted from the base station to the mobile station is Tx filtered at the duplexers 20a, 20b, 20c, 20d, and 20f, and is radiated through one transmission antenna 10a, 10c or one polarization. The reverse signal transmitted from the mobile station to the base station is received through two antennas 10a, 10b, 10c, and 10d or two polarized waves, and is Rx filtered and processed by the duplexers 20a, 20b, 20c, 20d, and 20f.

Referring to FIG. 1, a mobile communication base station system includes a plurality of antennas 10a, 10b, 10c, 10d, and 10e, a plurality of duplexers 20a to 20f, a plurality of radio frequency (RF) / intermediate frequency (IF) transceivers ( 30a, 30b, 30c) and modem 40. The modem 40 processes digital baseband signals for modulation and demodulation.

The RF / IF transceivers 30a, 30b, and 30c up-convert the baseband signal of the modem processor 40 to generate and amplify an RF signal for forward signal transmission, and then perform duplexers 20a to 20f. Transfer to the mobile station via In addition, the baseband signal generated by down converting the RF signal received via the duplexers 20a to 20f for downlink signal transmission is transmitted to the modem processor 40.

The duplexers 20a to 20f are composed of a Tx filter and an Rx filter. The duplexers 20a to 20f perform frequency filtering on the RF signals of the RF / IF transceivers 30a, 30b, and 30c for transmission to the mobile station. 10e) to transmit to the mobile station. In addition, the signal received from the mobile station to the antenna (10a, 10b, 10c, 10d, 10e) receives the frequency filtering and transmits to the RF / IF transceiver (30a, 30b, 30c).

Currently, the transmission structure of the forward signal in the commercial mobile communication base station system is modulated in the modem 40, the frequency up-converted and amplified in the RF / IF transceiver (30a, 30b, 30c), the amplified signal is the antenna (10a, 10c, 10e) and transmitted to the mobile station. At this time, the amplified signal is radiated and transmitted by one antenna (10a, 10c, 10e) or one polarization of the corresponding zone. The configuration of the mobile station for receiving the forward signal transmitted by the mobile communication base station having the above-described configuration will be described with reference to FIG.

2 is a block diagram showing an internal configuration of a mobile station of a mobile communication system.

The mobile station is composed of a transmit / receive antenna 15a, duplexer 25, RF / IF transceivers 35a, 35b, 35c, and a modem 45 as shown in FIG. 2, and the function of each component is the function of each component of the base station system. same. Although only one transmit / receive antenna was used up to IS-95A / B and CDMA2000-1x, MSM5500 (Mobile Station Modem5500) for 1xEV-DO terminal additionally provides a receive-only path for receive diversity of a mobile station. To this end, a receive-only antenna 15b may be additionally included in the configuration of the mobile station.

The RF / IF transceivers 35a, 35b, and 35c of the mobile station frequency-convert the signal received from the base station to generate a baseband signal and input it to the modem 45. The modem 45 performs demodulation and channel decoding. In particular, a mobile station uses a rake receiver for demodulation, and the output signal demodulated by the rake receiver is input to a channel decoder for channel decoding and channel decoded.

The mobile communication channel environment is a multi-path fading environment. In a code division multiple access (CDMA) receiving system, a Rake Receiver is used to improve performance in a multipath fading environment. The Rake Receiver obtains a diversity effect by detecting received signals received through different paths, demodulating the detected received signals by paths, and performing phase correction on the demodulated signals by paths. At this time, as a method of summing demodulated signals for each path, an MRC method is used.

Since received signals received through different independent paths have independent channel environments, there is a small probability that the received signals of all paths are simultaneously weakened. That is, when the received signal of a specific path is weak due to fading, the received signal of the other path is strong, so that the degradation of demodulation performance of the receiver is reduced. Therefore, the performance improvement effect is obtained by receiving signals received through several independent channel environments. This effect is called diversity effect. In the CDMA system, a rake receiver is used for the above path diversity effect, and as the number of demodulated paths increases, demodulation performance increases in proportion to the number.

3 is a conceptual diagram of space-time transmit diversity according to the present invention.

The present invention is to increase the capacity of the forward link by improving the performance of the forward link from the base station to the mobile station. The rake receiver of the mobile station, in particular the CDMA receiver, achieves a diversity effect by demodulating, summarizing and summing together mutually independent multipath components in a multipath fading mobile communication channel environment. Therefore, by adding a transmitting antenna and applying an artificial time delay to the added transmission path, a decomposable and valid multipath signal is additionally generated in the rake receiver, thereby inducing the demodulation performance of the mobile station rake receiver.

At this time, the determination of the artificial time delay value D (Delay Time) is a delay profile of the propagation environment around the base station and the search window of the mobile station modem so that mutual interference does not occur between valid multipath signal components from each transmitting antenna. Determine the size (Searcher Window Size).

In FIG. 3, when the time delay of the active component is T0 and the searcher window size is W, the time delay value D is determined in the range of T0 <D <W / 2-T0. Here, the searcher of the mobile station modem performs the function of finding the phase of valid multipath component signals. The searcher window size is a range in which a phase can be detected based on a signal that arrives first, and is a relatively large value compared to T0. In the urban area, which is the worst case, T0 is about 10us ~ 20us, and in this case, it is preferable to use 10us ~ 20us.

4 is a block diagram schematically illustrating a transmission structure of a mobile communication base station.

FIG. 4 briefly illustrates only the configuration unit 100 used for signal transmission in the configuration of the mobile communication base station shown in FIG. Here, the duplexer is omitted, and thus, the Tx filter included in the duplexer is not shown. In general, a signal output from a modem is output after being converted into an RF signal at the transceivers 30a, 30b, and 30c, and the signal output from the transceivers 30a, 30b and 30c is amplified by the amplifier 60 and then an antenna ( 10a, 10c, 10e) to the mobile station.

5 is a block diagram schematically illustrating an internal configuration of a space-time transmit diversity base station according to an embodiment of the present invention.

The space-time transmit diversity apparatus and method according to the present invention can be implemented using a delay element. The present invention is applicable to the use of vertical polarized antennas as well as X-pole antennas. 5 to 6B, the delay element may be applied at the front of the antenna or at the front of the amplifier, and according to various embodiments 200 and 300, as shown in FIGS. 5 to 6B depending on the position where the delay element is applied. Can be distinguished.

Referring to FIG. 5, the space-time transmit diversity apparatus 200 is located between the duplexers 20a and 20b and the RF / IF transceiver 30a and includes at least one delay element 52 and a plurality of amplifiers 62a. , 62b). Here, the space-time transmit diversity apparatus 200 is an embodiment in which the delay element 52 is coupled to the front end of the amplifier 62b.

The input terminal of the delay element 52 and the input terminal of the first amplifier 62a are coupled with the Tx output terminal of the RF / IF transceiver 30a, and the output terminal of the delay element 52 is coupled with the input terminal of the second amplifier 62b. It is. The output terminal of the first amplifier 62a is coupled to the Tx input terminal of the duplexer 20a, and the output terminal of the second amplifier 62b is coupled to the Tx input terminal of the duplexer 20b. Here, a power divider (not shown) is provided so that the power of the RF signal output from the Tx output terminal of the RF / IF transceiver 30a is applied to the first amplifier 62a and the delay element 52 without being degraded. It may be coupled between the RF / IF transceiver 30a and the first amplifier 62a and the delay element 52. Next, the operation of the space-time transmit diversity apparatus 200 having the above-described configuration will be described.

The RF signal output from the Tx output terminal of the RF / IF transceiver 30a is applied to the first amplifier 62a and the delay element 52. The RF signal applied to the first amplifier 62a is amplified by the first amplifier 62a and then applied to the Tx input terminal of the duplexer 20a. The amplified RF signal applied to the Tx input terminal of the duplexer 20a is Tx filtered and then transmitted through the antenna 10a. On the other hand, the RF signal applied to the delay element 52 is delayed by the time delay value D, and then applied to the input terminal of the second amplifier 62b. The time delayed RF signal applied to the second amplifier 62b is amplified by the second amplifier 62b and then applied to the Tx input terminal of the duplexer 20b. The RF signal applied to the Tx input terminal of the duplexer 20b is Tx filtered and then transmitted through the antenna 10b. Here, the antenna 10b operates as a diversity antenna.

Referring back to FIG. 5, the space-time transmit diversity apparatus 300 is located between the duplexers 20c and 20d and the RF / IF transceiver 30b and includes at least one delay element 54 and at least one amplifier. (64). Here, the space-time transmit diversity apparatus 300 is an embodiment in which the delay element 54 is coupled to the front end of the antenna 10d.

The input terminal of the amplifier 64 is coupled with the Tx output terminal of the RF / IF transceiver 30b, and the output terminal of the amplifier 64 is coupled with the Tx input terminal of the duplexer 20c and the input terminal of the delay element 54. The output end of delay element 54 is coupled to the Tx input end of duplexer 20d. Here, a power divider (not shown) is provided to the amplifier 64 and the duplexer to be applied to the duplexer 20c and the delay element 54 without degrading the power of the RF signal output from the output of the amplifier 64. May be connected between the 20c and the delay element 54. Next, the operation of the space-time transmit diversity apparatus 300 having the above-described configuration will be described.

The RF signal output from the Tx output terminal of the RF / IF transceiver 30b is applied to the amplifier 64. The RF signal applied to the amplifier 64 is amplified by the amplifier 64 and then applied to the Tx input terminal of the duplexer 20c and the output terminal of the delay element 54, respectively. The amplified RF signal applied to the Tx input terminal of the duplexer 20c is Tx filtered and then transmitted through the antenna 10c. On the other hand, the RF signal applied to the delay element 52 is delayed by the time delay value D, and then applied to the Tx input terminal of the duplexer 20d. The time delayed RF signal applied to the Tx input terminal of the duplexer 20d is Tx filtered and then transmitted through the antenna 10d. Here, the antenna 10d operates as a diversity antenna.

6A is a block diagram schematically illustrating a space-time transmit diversity apparatus according to an exemplary embodiment of the present invention, and FIG. 6B is a schematic view of a space-time transmit diversity apparatus according to another exemplary embodiment of the present invention. The block diagram shown.

Referring to FIG. 6A, the space-time transmit diversity apparatus 200 is located between the duplexer 20a and the RF / IF transceiver 30a and includes at least one diversity antenna 12, a Tx filter 22, At least one delay element 52 and a plurality of amplifiers 62a, 62b. Here, the space-time transmit diversity apparatus 200 is an embodiment in which the delay element 52 is coupled to the front end of the amplifier 62b.

The input terminal of the delay element 52 and the input terminal of the second amplifier 62b are coupled with the Tx output terminal of the RF / IF transceiver 30a, and the output terminal of the delay element 52 is coupled with the input terminal of the first amplifier 62a. It is. The output terminal of the first amplifier 62a is coupled to the input terminal of the Tx filter 22, and the output terminal of the second amplifier 62b is coupled to the Tx input terminal of the duplexer 20a. Here, a power divider (not shown) is provided so that the power of the RF signal output from the Tx output terminal of the RF / IF transceiver 30a is applied to the delay element 52 and the second amplifier 62b without being degraded. It may be connected between the RF / IF transceiver 30a and the delay element 52 and the second amplifier 62b. Next, the operation of the space-time transmit diversity apparatus 200 having the above-described configuration will be described.

The RF signal applied to the delay element 52 is delayed by the time delay value D and then applied to the input terminal of the first amplifier 62a. The time delayed RF signal applied to the first amplifier 62a is amplified by the first amplifier 62a and then applied to the input terminal of the Tx filter 22. The RF signal applied to the Tx filter 22 is Tx filtered and then transmitted via the diversity antenna 12. Meanwhile, the RF signal output from the Tx output terminal of the RF / IF transceiver 30a is applied to the second amplifier 62b and the delay element 52. The RF signal applied to the second amplifier 62b is amplified by the second amplifier 62b and then applied to the Tx input terminal of the duplexer 20a. The amplified RF signal applied to the Tx input terminal of the duplexer 20a is Tx filtered and then transmitted through the antenna 10a.

Referring again to FIG. 6A, the space-time transmit diversity apparatus 300 is located between the duplexer 20c and the RF / IF transceiver 30b and includes at least one diversity antenna 14 and at least one Tx filter. 24, at least one delay element 54 and at least one amplifier 64. Here, the space-time transmit diversity apparatus 300 is an embodiment in which the delay element 54 is coupled to the front end of the antenna 14.

The input terminal of the amplifier 64 is coupled with the Tx output terminal of the RF / IF transceiver 30b, and the output terminal of the amplifier 64 is coupled with the Tx input terminal of the duplexer 20c and the input terminal of the delay element 54. The output end of the delay element 54 is coupled to the input end of the Tx filter 24, and the output end of the Tx filter 24 is coupled to the diversity antenna 14. Here, a power divider (not shown) is provided to the amplifier 64 and the duplexer to be applied to the duplexer 20c and the delay element 54 without degrading the power of the RF signal output from the output of the amplifier 64. May be connected between the 20c and the delay element 54. Next, the operation of the space-time transmit diversity apparatus 300 having the above-described configuration will be described.

The RF signal output from the Tx output terminal of the RF / IF transceiver 30b is applied to the amplifier 64. The RF signal applied to the amplifier 64 is applied to the Tx input terminal of the post duplexer 20c and the output terminal of the delay element 54, respectively, amplified by the amplifier 64. The amplified RF signal applied to the Tx input terminal of the duplexer 20c is Tx filtered and then transmitted through the antenna 10c. On the other hand, the RF signal applied to the delay element 52 is delayed by the time delay value D, and then applied to the input terminal of the Tx filter 24. The time delayed RF signal applied to the input terminal of the Tx filter 24 is Tx filtered and then transmitted via the diversity antenna 14.

Referring to FIG. 6B, the space-time transmit diversity apparatus 200 is positioned between the first amplifier 60 and the RF / IF transceiver 30a and includes at least one diversity antenna 12 and a Tx filter 22. ), At least one delay element 52 and at least one first amplifier 62. In addition, the space-time transmit diversity apparatus 200 may be applied to the delay element 52 and the second amplifier 60 without degrading the power of the RF signal output from the Tx output terminal of the RF / IF transceiver 30a. It may further comprise a power divider 72 coupled between the RF / IF transceiver 30a and the delay element 52 and the second amplifier 60. Here, the space-time transmit diversity apparatus 200 is an embodiment in which the delay element 52 is coupled to the front end of the first amplifier 62.

The input terminal of the delay element 52 and the input terminal of the second amplifier 60 are coupled with the Tx output terminal of the RF / IF transceiver 30a, and the output terminal of the delay element 52 is coupled with the input terminal of the first amplifier 62a. . The output terminal of the first amplifier 62 is coupled to the input terminal of the Tx filter 22, and the output terminal of the Tx filter 22 is coupled to the diversity antenna 12. Since the operation process of the space-time diversity apparatus 200 is the same as that of FIG. 6A, description thereof is omitted.

Referring again to FIG. 6B, the space-time transmit diversity apparatus 300 is located between the amplifier 64 and the duplexer 20c and includes at least one diversity antenna 14 and at least one Tx filter 24. And at least one delay element 54. In addition, the space-time transmit diversity apparatus 300 may apply the amplifier 64 to be applied to the delay element 52 and the duplexer 20c without degrading the power of the RF signal output from the output terminal of the amplifier 64. And a power divider 72 connected between the delay element 52 and the duplexer 20c. Here, the space-time transmit diversity apparatus 300 is an embodiment in which the delay element 54 is coupled to the front end of the antenna 14.

The input terminal of the amplifier 64 is coupled with the Tx output terminal of the RF / IF transceiver 30b, and the output terminal of the amplifier 64 is coupled with the Tx input terminal of the duplexer 20c and the input terminal of the delay element 54. The output end of the delay element 54 is coupled to the input end of the Tx filter 24, and the output end of the Tx filter 24 is coupled to the diversity antenna 14. Here, a power divider (not shown) is provided to the amplifier 64 and the duplexer to be applied to the duplexer 20c and the delay element 54 without degrading the power of the RF signal output from the output of the amplifier 64. May be connected between the 20c and the delay element 54.

The present invention is not limited to the above embodiments, and many variations are possible by those skilled in the art within the spirit of the present invention.

As described above, according to the present invention, it is possible to apply the space-time transmit diversity apparatus and method to a conventional base station system without establishing a base station system that performs equipment replacement or transmission diversity function of the base station system.

In addition, by applying the space-time transmit diversity apparatus according to the present invention to the base station system, it is possible to increase the forward capacity of the conventional base station system.

In addition, the space-time transmission diversity apparatus and method according to the present invention can be applied to a mobile communication system currently in use and a new mobile communication system in the future, and can be applied to a wireless communication transmission system including a base station system and a repeater system of mobile communication. have.

Claims (13)

A space-time transmit diversity base station system, A plurality of antennas; A plurality of duplexers coupled to the antenna and having at least one Tx input and at least one Rx output; A plurality of amplifiers coupled to the Tx input terminal of the duplexer; At least one time delay element coupled to an input of at least one of said amplifiers; A Tx output terminal is coupled to an input terminal of the time delay element and an input terminal of at least one amplifier not coupled to the time delay element, an Rx input terminal is coupled to an Rx output terminal of the duplexer, and at least one Tx input terminal and at least one Rx At least one transceiver having an output stage; And And a modem having a Tx output terminal and an Rx input terminal coupled to the Tx input terminal and the Rx output terminal of the transceiver, respectively. The method of claim 1, And the plurality of antennas are physically spaced apart from each other. The method of claim 1, The space-time transmit diversity base station system, And a power divider coupled between the input end of the time delay element and the input end of at least one amplifier not coupled with the time delay element and the Tx output end of the transceiver. The method of claim 1, The time delay element, Space-time transmission diversity base station system characterized in that for outputting the input signal by the time delay value D. The method of claim 4, wherein The time delay value D is, And a time delay of the active component at the mobile station is T0, and when the searcher window size of the mobile station modem is W, a value in the range of T0 < D < W / 2-T0. A space-time transmit diversity base station system, A plurality of antennas; A plurality of duplexers coupled to the antenna and having at least one Tx input terminal and at least one Rx output terminal; at least one time delay element coupled to an input terminal of at least one duplexer of the duplexers; At least one amplifier coupled to a Tx input terminal of at least one duplexer not coupled with the time delay element of the time delay element and the duplexer; At least one transceiver having a Tx output stage coupled to an input of the amplifier, an Rx input coupled to an Rx output stage of the duplexer, and having at least one Tx input stage and at least one Rx output stage; And And a modem having a Tx output terminal and an Rx input terminal coupled to the Tx input terminal and the Rx output terminal of the transceiver, respectively. The method of claim 6, The space-time transmit diversity base station system, And a power divider coupled between the input terminal of the time delay element and the Tx input terminal of at least one duplexer not coupled with the time delay element and the amplifier. A space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, a transceiver and a modem, At least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; At least one first amplifier having an output coupled to an input of the Tx filter; And A time delay element having an output coupled to an input of the amplifier, And an input terminal of the time delay element is coupled to a Tx output terminal of the transceiver. The method of claim 8, The space-time transmit diversity apparatus, And at least one second amplifier having an output coupled to a Tx input of the duplexer, and having an input coupled to the Tx output of the transceiver. The method of claim 9, The space-time transmit diversity apparatus, Further comprising a power divider coupled between the input end of the time delay element and the input end of the second amplifier and the Tx output end of the transceiver, And the time delay element and the second amplifier receive a signal output from the transceiver by the power divider. A space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, an amplifier, a transceiver, and a modem, At least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; And A time delay element having an output coupled to an input of the amplifier, And an input terminal of the time delay element is coupled to an output terminal of the amplifier. The method of claim 11, The space-time transmit diversity apparatus, And a power divider coupled to an input terminal of the time delay element and an Tx input terminal of the duplexer, and having an input terminal coupled to an output terminal of the amplifier. A space-time transmit diversity apparatus used in a mobile communication base station including an antenna, a duplexer, a transceiver and a modem, At least one diversity antenna; At least one Tx filter having an output coupled to the diversity antenna; A time delay element having an output coupled to an input of the amplifier; And An amplifier having an output coupled to an input terminal of the time delay element and a Tx input terminal of the duplexer, And an input terminal of the amplifier is coupled to a Tx output terminal of the transceiver.