MXPA99010091A - Diversity of transmission and equalization of reception for link by ra - Google Patents

Abstract

In a mobile communication system, independent versions of a signal are transmitted by several antennas. The antennas are either spatially separated or orthogonally polarized with respect to each other, so that independent versions of the signal are not subjected to correlated fading. Each independent version of the signal is transmitted from a respective antenna to a transmission after the fixed delay of a previous version of a signal from a different antenna. The fixed delay is at least one bit of information of the signal. The received versions of the signal are matched in an equalizer or RAEE architecture to provide a composite signal. The equalizer has respective set of equalizer sockets that are separated from their adjacent sets of equalizer sockets by fixed delay. The RAKE architecture has respective sets of WEEE pulses that are separated from their adjacent series of RAKE pulses by fixed delay

Description

- - DIVERSITY OF TRANSMISSION AND EQUALIZATION OF RECEPTION FOR LINKS BY RADIO Field of the Invention The present invention relates to transmission diversity and equalization of reception in a mobile communications system to reduce the required transmitted energy needed to perform reliable communication.

Description of the Previous Technique In radio duplex systems such as cell phone systems include a direct link and a reverse link, the balance must be maintained to ensure quality. of complete communication. Typically, the reverse reception systems in a cellular base station employ diversity of reception with two or more receiving antennas with a widening of 7-10? so that the signal decline of the mobile signal transmission as warned by the REF .: 31471 - - base station can be mitigated. However, multiple antennas and reception channels are not useful for handheld or vehicle mounted communication devices in which small sizes and cost reduction are important. Since hand-held or vehicle-mounted communication devices can not employ reception diversity, the operation of the up-signal is typically 6-7 dB better than the operation of the down-signal. Conventionally, the link balance is maintained by using a stronger base station downstream signal power amplifier to compensate for the diversity of reception diversity in the mobile receiver so that signal performance is improved down. However, the increased power transmission has a negative impact on the budget or accumulation of signal energy, component size, weight and cost as well as resulting in increased system interference.

Figure 1 illustrates a conventional mobile communication system including the base station 60 having a single base station transmitting antenna 601 that wirelessly transmits a signal to a mobile station 70 having an antenna 701. Due to environmental obstacles such as buildings, trees or mountains located between the mobile station 70 and the base station 60, a signal is transmitted from the base station 60 and is received at the mobile station 70 together with a plurality of multipath signals which are delayed As for the time after the reflection of several obstacles. Figure 2 illustrates a multipath delay of the received signal due to environmental obstacles. An adaptive equalizer within the mobile station 70 has weights of varying magnitude and compensations or time deviations to compensate for the changes in the channel response due to the movement of the mobile station which changes the geometry of the reflection of the signals in the environment . Once a signal is received, the equalizer delays or delays the multiple paths of the received signal in an attempt to flatten the response of the receiving channel to compensate for the distortions for the radio channel caused by the multiple paths. The equalizer operates in the frequency domain to adaptively mitigate the multipath immersion.

In North America time division multiple access (TDMA) systems, which transmit narrow band signals of 30 kHz, the bit period is very long and the equalizer derivations of the mobile station are separated by 1/4 to 1 bit, which corresponds to echoes of multiple trajectories coming from great distances. Since the delays or delays of propagation from multiple trajectories due to environmental obstacles are relatively short (typically 1/4 of a bit of information), the mobile station's equalizers in TDMA systems do not effectively mitigate the multiple paths caused by environmental reflections because most of the multiple paths are in delays that are too short for the equalizer to handle them. In general, since the mobile station equalizers in the TDMA systems can not effectively mitigate the multipath immersion, the equalizers are usually maintained in a differential mode (equalizer OFF). On the other hand, the equalizing receivers in the mobile stations of the GSM systems (Global System for Mobile Communications) and the RAKE receivers in the mobile stations of the CDMA (multiple division code access) systems can significantly mitigate the multiple trajectories. However, the configuration of equalizer receivers and RAKE receivers for GSM and CDMA systems are complete.

Figure 3 illustrates the effects of conventional graphical diversity reception in terms of fading depth with respect to fading probability. For example, in the case of reception a branch using a single antenna, ten percent of the time the faded signal is 25 dB or more. However, in the case of receiving two leads in which two signals are received using two different, independent antennas that are separated spatially in the base station so that the signal as received in the two antennas does not fade simultaneously, ten percent of the time the signal fades 15 dB or more. In the case of receiving four leads using four antennas, ten percent of the time the signal fades by 10 dB or more. A diversity gain of 10 B is therefore realized for the reception of two derivations in contrast to the reception of a derivation using the same transmitted signal intensity. The fade margin is less than the reception of two taps in the case and the link can therefore be retained since a given reception criterion can be realized using a lower signal strength and multiple receive taps. However, reception diversity in a mobile station is impractical since portable or hand-held mobile units include multiple antennas that are spatially separated.

BRIEF DESCRIPTION OF THE INVENTION The present invention improves the operation of the descent signal in a mobile communication system without the increase of the energy transmitted in the base station by employing the transmit diversity of the base station combined with the equalization of the reception of the mobile station. A multi-channel transmitter that includes multiple transmit antennas transmits a signal and one or more additional independent versions of the same signal with delayed or delayed time to a mobile station. The energy of the independent received versions of the signal is matched in the frequency domain in the mobile station using an equalizer or time synchronized in a RAKE receiver to produce a composite signal. The effect of the diversity gain can thus be realized in a manner that increases the margin of fading immunity of the systems, and less than the total of the transmitted energy is required and the generated interference is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates a conventional mobile communication system, which includes a base station having a single transmission antenna; Figure 2 illustrates multiple trajectories of a signal received in the mobile station of Figure 1, in the time domain; Figure 3 illustrates the effects of receptor diversity for the reception of multiple leads; Figure 4 illustrates a mobile communication system of one embodiment of the invention; Figure 5 illustrates the transmission diversity of an embodiment of the invention in a base station including a plurality of transmission antennas; Figure 6 illustrates a transmitter of the base station of one embodiment of the invention; Figure 7 illustrates a mobile station receiver of one embodiment of the invention; Figure 8 illustrates a mode of a receiver equalizer of the mobile station of Figure 7; Figure 9 is a graph illustrating the multiple paths received in a first independent version of a transmitted signal with no delay and multiple paths received from a second independent version of the transmitted signal at a predetermined time delay after transmission of the first version, as it is operated in the equalizer portions of figure 8; Figure 10 illustrates the independent fading of the independent versions of the signal; And Figure 11 illustrates a RAKE architecture of an alternative mode of the receiver of the mobile station of Figure 7.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES Figure 4 illustrates a mobile communication system of a preferred embodiment of the invention utilizing transmission diversity and reception equalization. The mobile communication system can be a mobile communication system TDMA, GSM, or CDMA. As illustrated, the mobile communication system includes a plurality of base stations 30 and 31 that transmit wirelessly and receive communication signals to / from the mobile station 10. Although not illustrated, each of the base stations 30 and 31 may cover respective sectors. The mobile switching center 40 is connected to the plurality of base stations 30 and 31 via the communication lines L and further is coupled to the public switched telephone network (PSTN) 50 to allow communication between the mobile station 10 and another part in the PSTN 50. Although two respective base stations are illustrated, it should be understood that the mobile communication system may include any number of base stations.

In order to realize or achieve the transmission diversity, two or more independent versions of the same signal are transmitted from the base station 30 to the mobile station 10 for example. As illustrated in greater detail in Figure 5, in a preferred embodiment the base station 30 includes two antennas 301 and 302 that are spatially separated horizontally from at least 7-1O? where ? It is the wavelength. The antennas are spatially separated so that independent versions of the same signal can be transmitted to the mobile station 10 by different effective radio channels that are not subject to identical fading. In the alternative, each of the antennas 301 and 302 can be separated vertically. In a further embodiment, each of the antennas 301 and 302 can be orthogonally polarized (vertical / horizontal dual polarization or biased, dual polarization) with respect to each other to provide independently different fading transmissions. In yet another alternative embodiment, transmission independence can be provided through a combination of spatial separation and orthogonal polarization of the antennas 301 and 7 302. On the other hand, although only two antennas 301 and 302 are illustrated, the base station can transmit the independent versions of the same signal by any number of antennas for further improvement of the diversity effect.

In order to effectively effect the diversity effect, the independent versions of the signal transmitted from the base station 30 and received in the mobile station 10 must be separated from each other. In order to avoid the RF energy of the independent versions of the signal transmitted from only the combination during transmission to form a combined signal received in the mobile station 10 having phase, network, random, and phase nulls, network, random, independent versions of the transmitted signals they are transmitted from the antennas 301 and 302 of the base station 30 not simultaneously. Accordingly, Figure 5 illustrates a first independent version of the signal and the corresponding multiple paths as they are transmitted from the antenna 301 to the mobile station 10 indicated by solid or continuous lines. Figure 5 further illustrates a second independent version of the signal and the corresponding multiple paths as transmitted from the antenna 302 to the mobile station 10 indicated by dashed lines, the second independent version transmits from the antenna 302, a delay or delay of time, predetermined,?, after the transmission of the signal from the antenna 301. In other words, the signal transmits from the antenna 302 an artificial time delay after the transmission of the signal from the antenna 301.

- Figure 6 illustrates in more detail the transmitter of the base station 30 of figure 5. The input data or the voice In are provided to the encoder 310. In the mobile communication systems TDMA and GSM, the encoder 310 can perform for example pulse code modulation (PCM). In a mobile communication system, the encoder 310 may be a variable speed vocoder (data compression or video compression) that uses conventional coding algorithms as it should be within the level of ordinary skill. The encoded signal is provided to interleaver 312 which intersperses the encoded signal to mitigate the loss of complete blocks of data due to fading. The interleaved data is provided to the modulator 314 which modulates the interleaved data using DQPSK (p / 4, differential quadrature change keying) for TDMA systems, GMSK (minimum gauss shift keying) for QPSK systems (keying for change) of quadrature phase) for CDMA systems, for example.

The output of the modulated signal from the modulator 314 is provided to the amplifier 330 which amplifies the modulated signal and provides the amplified signal to the antenna 301 for wireless transmission to the mobile station 10. The modulated signal is also provided from the modulator 314 for fixing the delayed or delayed, fixed element 320 which delays the modulated signal by a predetermined time delay? and then the delayed signal subsequently comes out. The predetermined time delay?, Is selected to be greater than a bit period of information of the transmitted signal to prevent RF lobing where nulls are formed in the transmitted route as in the case of simultaneous transmission from an array of antennas fed from a common source, and the interference between symbols where the transition edges between the digital states suffer from time dispersion.

The amplifier 331 amplifies the delayed signal output from the delay element 320 and provides the amplified signal to the antenna 302 for wireless transmission to the mobile station 10. Thus, the signal is transmitted from the antenna 302 to the mobile station 10 independently of already a predetermined time delay?, after the transmission of the signal from the antenna 301. The modulated signal is also provided to the delay element 32N which delays the modulated signal by a predetermined delay of time N? and then the delayed signal subsequently comes out. The amplifier 33N amplifies the delayed signal provided from the delay element 32N and then provides the amplified signal to the antenna 30N for wireless transmission to the mobile station 10. Thus, the signal is transmitted from the antenna 30N to the mobile station 10 independently of y in a predetermined time delay N? after the transmission of the signal from the antenna 301 It should be understood that N is an integer number and that the number of transmission branches in the base station is not limited. The diversity effect improves as the number of transmission leads increases.

Figure 7 illustrates a preferred mode of a receiver of the mobile station 10 of Figure 4. The antenna 101 wirelessly receives the signals transmitted from the antennas 301, 302 and 30N of the transmitter of the base station of Figure 6. A signal is provides as received, the demodulator 102 that demodulates the signal in accordance with the corresponding modulation scheme used in the base station 30. For example, the demodulation DQPSK, GMSK and QPSK is effected by the demodulator 102 for the TDMA systems, GSM and CDMA, respectively. The demodulated signal is provided to the equalizer 104, which is described hereinafter, so that independent versions of the signal such as that transmitted by the antennas 301, 302 and 30N with the delay can be combined to form a composite signal. The composite signal leaving the equalizer 104 is provided to the deinterleaver 106 and deinterleaved in a complementary manner with the interleaving performed by the interleaver 312 of the transmitter of the base station of FIG. 6. The deinterleaved signal is provided to the decoder 108 which performs the corresponding decoding to provide the output signal, which "may be voice or data.

Figure 8 illustrates an equalizer of a preferred embodiment of the invention for use in TDMA systems. The equalizer 104 is a divided equalizer that includes the equalizer portions 120 and 130 which are each three-tap adaptive equalizers. The fixed delay element 14.0 is included as a coupling along or along with the delayed or delayed lines between the equalizer portions 120 and 130. It should be understood that Figure 8 illustrates an example of an equalizer for a mobile station that receives two independent versions of a signal since two equalizer portions are implemented. Generally, equalizer 104 includes the same number of equalizer portions N as N antennas by which independent versions of the signal are transmitted from the base station. A respective fixed delay or delay element, 140, is coupled between each pair of equalizer portions.

The demodulated signal output from the demodulator 102, FIG. 7, is provided to the variable or fixed delay element 121 and to the multiplier 123 of the equalizer portion 120 of FIG. 8. The delay element 121 delays the demodulated signal by a delay time Ti and provides a delayed output of the delay element 122 and the multiplier 124. The delay element 122 further delays the output of the delay element 121 by a delay time t2 and provides a delayed output to the multiplier 125. The delay elements 121 and 122 form a delay line taken and each provides a delay of 1/4, 1 / 2, or a full information bit period of the transmitted signal, but - - generally provides a much shorter delay than a full information bit period. The delayed or delayed output of the delay element 122 is also provided to fix the long delay element 140 as a delayed output of the equalizer portion 120. Each of the multipliers 123, 124 and 125 respectively multiply the corresponding inputs by weightings of magnitude of lf h2 and h3. The magnitude weights hi, h2 and h3 are provided in an adaptive manner to equalize the signal in a conventional manner. The multiplied outputs of each of the multipliers 123-125 that are provided to the adder 126 that adds the multiplied outputs to provide an aggregate output of the equalizer portion 120 that is output from the equalizer portion 130.

With respect to the delay elements 121 and 122 that form the delay line, taken, in the equalizer portion 120, in the North American TDMA systems, the bit period is very long in relation to the echoes of the multiple, natural trajectories , environmentally induced. A two shot equalizer is the largest equalizer used in practice since the use of more shots does not produce a benefit. Typically, the delay between the taps is as small as possible, usually 1/4 of a bit period. Other equalizers can use 1/2 or a full bit delay between successive takes. Because of the long or large bit period in TDMA systems that correspond inversely with the very narrow bandwidth of 30 KHz, the 1/4 bit period separating the second tap is relatively ineffective in compensating for the distortions channel and consequently less than 1 dB of gain is achieved. Accordingly, the TDMA equalizer is often changed and differential detection is used instead without compensation for intersymbol interference. On the other hand, in GSM systems, environmentally induced multipath echoes create or cause severe inter-symbol interference that must be compensated by an equalizer. In GSM systems, 5 to 8 tap equalizers are typically employed and the effective gain is much greater than 10 dB of budget enhancement or link accumulation. For equalizer-based channel compensation, the distortion produced due to multiple paths is analyzed in the frequency domain and offsets for successive sockets are placed to create or form a flat response through the channel bandwidth.

Returning to the TDMA equalizer of FIG. 8, the element 140 delays the delayed output of the equalizer portion 120, as provided from the delay element 122, by the predetermined time delay N? described with reference to Figure 6. The long, set delay element 140 provides a delay of at least one information bit period, preferably two or three bit periods of information of the transmitted signal, so that it can be separate the independent versions of the received signal. The output of the fixed long delay element 140 is provided to the delay element 131 and the multiplier 133 of the equalizer portion 130. The delay element 131 delays the output of the delay element, set, 140, by the delay time 3 and provides a delayed output to the delay element 132 and the multiplier 134. The delay element 132 delays the output of the delay element 131 by the delay time t4 and provides a delayed output or delayed to the multiplier 135. The delay elements 131 and 132 - - form a delay line, taken, and provide delay as described previously with respect to the delay elements 121 and 122. The multipliers 133, 134 and 135 respectively multiply the corresponding inputs by the magnitude weights h4, h5 and h6 to provide the corresponding multiplied outputs. As previously described, the magnitude weights h4, h5 and h6 are provided in an adaptive manner to equalize the signal in a conventional manner. The multiplied outputs of each of the multipliers 133-135 are provided to the adder 136 which adds the multiplied outputs to provide a summed output that is output to the adder 137. The adder 137 adds the summed output of the equalizer portion 120 provided from the adder 126 and the summed output of the adder 236 provides an output signal of the equalizer corresponding to the composite signal described with respect to Figure 7 that exits towards the deinterleaver 106. As can be seen in view of Figure 8, the element long, set delay, 140, separates the taps of the delay line taken from the equalizer portion 120 from the taps of the taken delay line of the equalizer portion 130 by the set delay. As previously described, in order to realize or achieve the transmitted diversity effect, the independent versions of the signal transmitted from the base station 30 and received in the mobile station 10 must be separable. The transmission of the independent versions of the signal with the artificial delay from the transmitter of the base station as illustrated in figure 6 make it possible to separate the independent versions with the reception. Using a default delay time? greater than an information bit period of the transmitted signal prevents RF lobing where nulls are formed in the transmission form as in the case of simultaneous transmission from an array of antennas fed from a common source, and intersymbol interference where the transition edges between digital states suffer from time dispersion. Accordingly, in a preferred embodiment of the invention, the predetermined delay time?, Is a period of information bit of the transmitted signal. More preferably, the predetermined delay time? Is at least two or three periods of information bit of the transmitted signal. As described with respect to Figure 5, a signal transmitted from the antenna 301 to the mobile station 10 includes for example multiple paths that are delayed due to reflection of the signal in the environmental obstacles illustrated in Figure 2. In accordance , the signal transmitted from the antenna 301 of the transmitter of the base station is first received in the mobile station 10 and then is provided to the equalizer 104. The signal including the multipaths is provided to the equalizer portion 120 of the equalizer 104 illustrated in FIG. Figure 8, which attempts to mitigate multipath imbibing to provide an equalized or equalized signal as an output of adder 126. The signal including the multipath is provided from the delay element 122 to the fixed delay element, 140, which delays the signal by the predetermined delay time?, and subsequently provides the signal including multiple paths to portion 130 of the equalizer for equalization or equalization.

In view of the predetermined delay time?, Imparted by the fixed delay element 140, the independent version of the signal transmitted by the antenna 302 of the transmitter of the base station of FIG. 6 as delayed by the delay element 320 and which includes multiple paths, is received and provided to the equalizer portion 120 at the same time that the first independent version transmitted from the signal is provided from the set delay element, 140, to the equalizer portion 130. Accordingly, as point given in time, the equalizer potion 130 attempts to mitigate the multipath immersion of the independent version of the signal transmitted from the transmitter antenna 301 of the base station and the equalizer portion 120 simultaneously tries to mitigate the mismatch of the trajectories multiple of the independent version of the signal transmitted from the antenna 302 at the station transmitter n base. Equalized or equalized independent versions of the signal as the output of adders 126 and 136 are summed in adder 137 to provide the composite signal.

- Figure 9 illustrates the independent versions of the signal including the multiple trajectories such as those operated in the equalizer portions 120 and 130 of Figure 8 at a corresponding point in time. The independent version of the signal that is first transmitted from the antenna 301 of the transmitter of the base station and that includes multiple trajectories is indicated by solid lines. At the corresponding point in time illustrated in Figure 9, this independent version of the signal including multiple paths is operated in the equalizer portion 130 as indicated. The independent version of the signal that is transmitted from the antenna 302 of the transmitter of the base station and that includes multiple trajectories is indicated by the dashed lines. At the corresponding time point illustrated in Figure 9, this respective independent version of the signal including multiple trajectories is operated in the portion 120 of the equalizer. The independent versions of the signal as illustrated are separated by the predetermined delay time?, When transmitted and thus operated simultaneously by the equalizer portions 120 and 130 which are separated from one another by the fixed delay 140.

Accordingly, a separate version of the signal is transmitted from the antenna 302 at the predetermined delay time,, then a separate version of the signal is transmitted from the antenna 301. The independent versions of the signal must thus be separated as shown. described above by the equalizer 104 and must be combined to provide a composite signal. On the other hand, the independent versions of the signal are transmitted from different antennas 301 and 302 that are separated either spatially and / or orthogonally polarized with respect to one another. The independent versions of the signal are thus transmitted by different paths and therefore are not subject to a correlative fading. The independent versions of the signal must thus be combined to provide a composite signal having an effective signal strength greater than any of the independent versions of the signal due to the effects of diversity gain.

As illustrated in FIG. 10, the independent version of the first signal transmission from the antenna 301 is subject to different fading than the independent version of the transmitted signal by a predetermined delay time?, Thereafter by the antenna 302 When the independent versions of the signal are combined to provide a composite signal in the equalizer 104, the network effect is more simply than the aggregation of the signal strength of the independent versions of the signal so that the composite signal has merely twice the signal strength of any of the independent versions of the signal taken alone. This mere bending of the signal strength should correspond to an increase of 3 dB. In view of the transmission diversity gain realized or obtained in the present invention, the effective signal strength of the composite signal may currently be 6-15 or more dB stronger than any of the independent versions of the signal. The receiver of the mobile station of Figure 7 has been described as including the equalizer 104 which is illustrated in greater detail in Figure 8. The equalizer of Figure 8 is described as a TDMA equalizer but can be used as a GSM equalizer changing the numbers of the shots, as previously described. In a further preferred embodiment of a mobile communication receiver for CDMA systems, the equalizer 104 of Figure 7 is replaced with the specialized RAKE architecture, 200, illustrated in Figure 11. In general, RAKE architectures for CDMA systems experience distortions. channel induced multiple trajectories. However, the bandwidth of CDMA systems is very wide, which corresponds to a very short bit period, and environmentally induced echoes are very far apart in terms of bit numbers. Inter-symbol interference encompasses many bits in the CDMA systems, rather than just two adjacent bits for the TDMA systems or eight adjacent bits for the GSM systems as previously described. The system architecture therefore uses variable time delays between a small number of RAKE pulses to avoid complex designs of equalizers with hundreds or thousands of sockets, most of which must be placed in zero magnitude. Accordingly, in a RAKE in the CDMA system, only the upper part of three or four echoes are tracked, synchronized and summed to form a compensated signal. The scanning function is used to select delays or delays that are variable in the time domain to identify the delay compensations where the echoes are located. As illustrated in more detail in Figure 11, the demolded I and Q components are input to the bus or data bus 210 of the RAKE 200 architecture. The demolded I and Q signal components are provided from the bus or data bus 210 to the search unit 212 which searches for the echoes of the received signal based on the signal components Q and I. The search unit 212 provides an indication of where the echoes are in the received signal to the pulse control unit 214 which provides control signals to the RAKE pulses 216, 218 and 220. The RAKE pulses 216, 218 and 220 are each coupled with the signal components Q and I provided together with the bus or data bus 210 and each delay a respective echo of the received signal by a specific delay in accordance with the control signals provided from the pulse control unit 214. The RAKE 216, 218 and 220 pulses are from this to adaptive to delay the respective multi-path echoes of a received signal as illustrated in FIG. 2 so that the outputs of the RAKE pulses 216, 218 and 220 as provided to the adder 230 include the respective echoes of the received signal that are synchronized one with another in time to effectively mitigate the embarrassment.

The I and Q components are also provided from the bus or data bus 210 to the set delay element, 240, which delays I and Q components by default delay time? The signal components I and Q delayed, are provided from the set delay element 240 to the bus or data bus 260. The signal components I and Q are provided from the bus or data bus 260 to the search unit 262. The search unit 262, the pulse control unit 264 and the RAKE pulses 266, 268 and 270 function similarly as the search unit 212, the pulse control unit 214 and the rake pulses 216, 218 and 220 respectively. The pulsation control unit 214 provides a control signal to the search unit 262 and the pulsation control unit 264 for the coordination of the search and the pulsation control based on the indication of where they are located - the echoes of the signal as determined by the search unit 212. The RAKE pulses 266, 268 and 270 are thus adaptable to provide outputs to the adder 230 which includes the respective echoes of the received signal that are synchronized with each one in time for mitigate the embarraduras. The adder 230 of the RAKE 200 architecture provides a summed output to a deinterleaver which provides a deinterleaved output to a decoder. In the CDMA system of this particular embodiment, the decoder can be, for example, a Viterbi light decoder.

A signal transmitted from the antenna 301 of the base station 30 of FIG. 5 is demodulated by the corresponding demodulator which provides the components of the signal I and Q • of the signal for the data bus 210 of the RAKE 200 architecture. The signal including the multiple paths is processed by the set of RAKE pulses 216, 218 and 220 to mitigate the embarrassment. The I and Q components of the received signal are then delayed by the fixed delay element 240 and then provided to the data bus 260 to be processed by the RAKE pulse set 266, 268 and 270. At this particular time, the independent version of the signal transmitted from the antenna 302 of Figure 5 (as demodulated by the corresponding demodulator) is provided as the components of the I and Q signal to the data bus 210. The I and Q components of the independent version of delay or delay of the signal including the multiple trajectories transmitted from the antenna 302, are processed by the set of RAKE pulses 216, 218 and 220 simultaneously as the set of pulsations RAKE 266, 268 and 270 that processes the components of the signal I and Q of the signal transmitted from the antenna 301. The outputs of the RAKE pulses are provided to the adder 230, from which a composite signal is output which It has an effective intensity signal, greater than, any of the independent versions of the signal due to the effects of the gain diversity.

It is understood that the RAKE architecture of Figure 11 illustrates an example of a mobile station that receives two independent versions of a signal such as that transmitted from a base station, since two RAKE pulses are implemented. In general, the RAKE 200 architecture includes the same number of RAKE pulse sets as antennas, on which the independent versions of the signal are transmitted, from the base station. A respective fixed delay element 240 is coupled between each pair of RAKE pulse set. It is understood that the search units, pulse control units and RAKE keys are typically elements of RAKE architecture.

The invention should not be limited in view of the corresponding figures and description thereof. For example, the equalizer of Figure 8 can be simplified by certain types of environments. For a TDMA environment that uses a narrow effective band with a 30KHz for example, there is a small widening or extension of the delay in the environment because the bit period is very long. For such a specific case, the equalizer of Figure 8 can be reduced to a single two-tap equalizer, wherein the equalizing portion 120 includes only one multiplier 123 as a first fixed tap and the equalizing portion 130 can not include delay elements 121. , 122, 131 and 132 and multipliers 124, 125, 134 and 135. Only the fixed delay element 140 can be implemented between the equalizer portions 120 and 130, thus simplifying the equalizer, so that the weight can be reduced, size and cost It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property.

Claims (30)

- - CLAIMS

1. A base station for transmitting an input signal, characterized in that it comprises; a first antenna for transmitting the input signal; a delay or delay element that delays the input signal to produce a delay input signal; and a second antenna for transmitting the delayed input signal independently of the transmission of the input signal by said first antenna.

2. The base station of claim 1, characterized in that said delay element delays the transmission of the input signal, delayed by at least one bit period of information of the input signal after the transmission of the input signal.

3. The base station of claim 1, characterized in that it further comprises a plurality of additional antennas, said delay element includes a plurality of different delays to delay or delay the input signal to provide a plurality of delayed input signals, said plurality of different delays is placed so that an antenna nth of said plurality of additional antennas, transmits to one of the pluralities of the delay input signals, a predetermined time after and independently of the transmission of another, a plurality of signals of delay input via an antenna (nl) of the plurality of additional antennas, n is an integer greater than 1.

4. The base station of the claim 1, characterized in that said first and second antennas are spatially separated one from the other by 7-10 ?.

5. The base station of claim 1, characterized in that said first and second antennas are orthogonally polarized with respect to one another. - -

6. The base station of claim 1, characterized in that said first and second antennas are spatially separated and multi polarized with respect to one another.

7. A method for transmitting an input signal, characterized in that it comprises the steps of: transmitting the input signal from a first antenna; delay the input signal to produce a delayed or delayed input signal; and transmitting the delayed input signal from a second antenna independently of the transmission of the input signal by the first antenna.

8. The method for transmitting an input signal of claim 7, characterized in that said delaying or delaying step comprises the delayed transmission of the delay input signal by at least one bit period of information of the transmission of the input signal after Of the same. - -

9. The method for transmitting an input signal of claim 7, characterized in that it further comprises the steps of: delaying the input signal with a plurality of different delays to produce a plurality of delayed or delayed input signals; and transmitting the plurality of delayed input signals by a plurality of additional antennas; the plurality of different delays is placed so that an antenna nth of said plurality of additional antennas, transmits to one of the pluralities of the delay input signals, a predetermined time later and independently of the transmission of another plurality of signals of delay input via an antenna (nl) of the plurality of additional antennas, n is an integer greater than 1.

10. The method for transmitting an input signal of claim 7, characterized in that it further comprises the spatial separation of the first and second antenna one from the other by 7-10 ?.

11. The method for transmitting an input signal of claim 7, characterized in that it further comprises orthogonally polarizing the first and second antennas with respect to one another.

12. The method for transmitting an input signal of claim 7, characterized in that it further comprises spatially separating and orthogonally polarizing the first and second antennas with respect to one another.

13. A mobile station of a mobile communication system, characterized in that it comprises: an antenna for receiving multiple versions of a signal transmitted at least twice with a fixed delay between each transmission, the fixed delay is at least one bit of information of the signal; and an equalizer to equalize each version of the signal received by said antenna to provide a composite signal, said equalizer having respective sets of equalization sockets that are separated from an adjacent set of equalization sockets, by means of the set delay.

14. The mobile station of claim 13, characterized in that said equalizer comprises: a first equalizing portion for delaying the received signal in a first delay line of sockets, in delayed multiplying signals provided from a set of equalizing sockets of the first line delaying the taps with the first weighting coefficients to provide first signals by multiplying and adding the first multiplied signals to provide a first matched signal; a delay element set to delay an output of the first line of the first shot by the fixed delay; and a second equalizing portion for delaying the output of said fixed delay element in a second tap delay line, in delayed multiplier signals provided from a set of equalizing jacks of the second tap delay line with the second weight coefficients to provide second - - multiplied signals, summing the second multiplied signal, to provide a second matched signal and adding the first and second equalization signals to provide the composite signal.

15. The mobile station of claim 13, characterized in that the signal is transmitted to the mobile station independently from a plurality of antennas of a base station of the mobile communication system.

16. The mobile station of claim 15, characterized in that the signal is transmitted from a first of the plurality of antennas of the base station and the transmission is transmitted independently of an antenna nth of the plurality of antennas after the delay set of the signal from an antenna (nl) of the plurality of antennas, n is an integer greater than 1.

17. The mobile station of claim 15, characterized in that the plurality of antennas of the base station is spatially separated by 7-10?. - -

18. The mobile station of claim 15, characterized in that the plurality of antennas of the base station are orthogonally polarized with respect to one another.

19. The mobile station of claim 15, characterized in that the plurality of antennas of the base station are spatially separated and orthogonally polarized with respect to one another.

20. A communication diversity method for a mobile station, characterized in that it comprises the steps of: receiving multiple versions of a transmitted signal at least twice with a fixed delay between each transmission, the set delay is at least one bit of information of the signal; and equalizing each version of the received signal using an equalizer having respective series of equalizer sockets, each one is separated from an adjacent set of equalization sockets by the set delay to provide a composite signal. - -

21. The communication diversity method of claim 20, characterized in that the equalizing step comprises: delaying the received signal in a first tap delay line; multiplying the delayed signals provided from a set of equalizing sockets of the first tap delay line with the first weighting coefficients to provide multiple multiplied signals; add the first multiplied signals to provide a first matched signal; delaying an output of the first tap delay line by the delay set to provide a first signal; delay the first signal on a second tap delay line; multiplying the delay signals provided from a set of equalization shots of the second shot line with a second weighting coefficient to provide second multiplied signals; adding the second multiplied signals to provide a second matched signal; and - adding the first and second equalization signals to provide the composite signal.

22. The communication diversity method of claim 20, characterized in that the signal is transmitted to the mobile station, independently of a plurality of antennas of a base station.

23. The communication diversity method of claim 22, characterized in that the signal is transmitted from a first plurality of antennas of the base station and the transmission is transmitted independently of an antenna nth of the plurality of antennas after the fixed delay of the signal, from an antenna (n-1) of the plurality of antennas, n is an integer greater than 1.

24. The communication diversity method of claim 22, characterized in that the plurality of antennas of the base station are spatially separated by 7-10 ?. - -

25. The communication diversity method of claim 22, characterized in that the plurality of antennas of the base station are orthogonally polarized with respect to one another.

26. The communication diversity method of claim 22, characterized in that the plurality of antennas of the base station are spatially separated and orthogonally polarized with respect to one another.

27. A mobile station of a mobile communication system, characterized in that it comprises: an antenna for receiving multiple versions of a signal transmitted at least twice with a fixed delay between each transmission, the fixed delay being at least one bit of information of the signal; and a RAKE architecture to process each version of the signal received by said antenna to provide a composite signal, said RAKE architecture has respective sets of RAKE pulses, each one separates - of an adjacent set of RAKE pulses for the set delay.

28. The mobile station of claim 27, characterized in that said RAKE architecture comprises: a first bus or data bus coupled to the received signal; a first set of RAKE pulses coupled to said first data bus to delay the received signal by respective delays to provide the first RAKE signals; a fixed delay element for delaying an output of said first data bus by the set delay; a second data bus coupled to an output of said delay element; a second set of RAKE pulses coupled to the second data bus to delay the output of said fixed delay element by respective delays to provide second RAKE signals; and an adder to add the first and second signals to provide the composite signal.

29. A communication diversity method for a mobile station, characterized in that it comprises the steps of: receiving in the mobile station multiple versions of a signal transmitted at least twice with a fixed delay between each transmission, the delay signal is at least one bit of information of the signal; and processing each version of the signal using a RAKE architecture having respective sets of RAKE pulses, each is separated from an adjacent set of RAKE pulses by the set delays.

30. The communication diversity method of claim 29, characterized in that said step of the method comprises; coupling the received signal to a first bus or data bus; delaying the received signal by respective delays with a first set of RAKE pulses coupled to the first data bus to provide first RAKE signals; - - delaying an output of the first data bus by the delay set to provide a first signal; coupling the first signal to a second data bus; delaying the first signal by respective delays with a second set of RAKE pulses coupled to the second data bus to provide a second RAKE signal; and adding the first and second RAKE signals to provide the composite signal.