Multiple antenna transceiver and operating method thereof

Multi-antenna transceiver and its operation method

Multiple Antenna Transceiver And Operating Method Thereof

The present invention generally relates to wireless communication. More specifically, the present invention relates to a multiple-antenna transceiver and its operation method.

Traditional wireless systems use radio frequency (RF) transmitters to generate output signals to be applied to communication antennas between stations separated by a certain distance. In a mobile wireless network, one station may be a mobile station (MS), and the other station may be a base station (BS). As the mobile station moves within the area covered by the entire wireless network, the path loss between the mobile station and the base station changes due to many environmental factors. These environmental factors include changes in the distance between the stations and blocking or attenuation in the environment. The presence of objects that transmit signals from one station to another.

In order to ensure the normal operation of the network, according to the path loss between the base station and the mobile station that needs to be overcome, the base station instructs the mobile station to increase or decrease its transmission power, so that the base station continuously receives signals from the mobile station as the channel conditions change. On the base station, the mobile station must maintain a certain signal strength so as not to inhibit the detection of its transmitted signal. At the critical distance of some base stations, depending on the detailed physical environment between the mobile station and the base station, the mobile station will no longer be able to increase its output power to maintain the required signal strength. At this point, unless the base station can communicate with the mobile station by means of the neighboring base station, the communication between the mobile station and the base station can no longer be maintained, and the connection will be lost. Therefore, the maximum output power capability of the mobile station is a key parameter, which finally determines the expected distance between the mobile station and the base station, and thus determines the necessary distance for reliable coverage in a mobile network. The distance and number of base station sites required. However, the greater the number of base station sites, the greater the The greater the cost of the road. Therefore, it is necessary to expand the output power capability of the mobile station to ensure reliable coverage with the minimum number of base station sites.

Therefore, an important part of the mobile station is the power amplifier used to transmit signals to the base station. Power amplifiers usually have a maximum output power level. One way to achieve reliable communication with the base station is to ensure that the power amplifier is equipped with enough power to overcome attenuation and other harsh environments that sometimes exist in wireless media.

However, it is not always feasible to equip mobile stations with high-power amplifiers for the following reasons: (1) There is a limit on the total power available for equipment consumption; (2) High-power amplifiers may cause overheating and then Become ineffective; (3) High-power amplifiers may be expensive; (4) High-power amplifiers may be too large to be suitable for small mobile terminals with size restrictions.

In an effort to increase the output power of a mobile station instead of increasing the power of an existing amplifier, it is sometimes economical and effective to combine one or more low-power amplifiers. Combining the output of multiple amplifiers may yield additional advantages, including the ability to transmit from a single spatial stream or multiple spatial streams.

It is desirable to provide a method for optimizing the transmission power of a multi-power amplifier of a subscriber station transceiver, the subscriber station transceiver including multiple antennas.

An embodiment includes a multi-antenna transceiver. The multi-antenna transceiver includes a multi-port network having a plurality of first ports and a plurality of second ports, wherein at least one of the second ports responds to at least two of the first ports. The multi-antenna transceiver also includes a plurality of antennas, and each antenna is connected to the second port.

Another embodiment includes a multi-antenna subscriber unit.

Another embodiment includes a method of operating a transceiver including a multi-port network. The method includes coupling a plurality of transmission signals to a plurality of first ports of a multi-port network, and a plurality of antennas, each antenna being coupled to a second port of the multi-port network, wherein at least one of the first ports is The two ports respond to at least two of the first ports.

According to one aspect, a multi-antenna subscriber unit architecture (architecture) includes: A multi-port network with multiple first ports and multiple second ports, wherein at least one of the second ports responds to at least two of the first ports; multiple antennas, each antenna connected to the second port.

According to another aspect, a method of operating a transceiver including a multi-port network includes: coupling a plurality of transmission signals to a plurality of first ports of the multi-port network; coupling a plurality of first ports of the multi-port network Two ports to multiple antennas; wherein at least one of the second ports responds to at least two of the first ports.

Preferably, the method further includes, at least part of the received signal based on the characterization, setting at least one phase of the plurality of transmitted signals by controlling at least one phase and amplitude of the transmitted signal of at least one of the multi-port networks And the amplitude to form at least one output transmit signal.

Preferably, the method further includes coupling a plurality of output power amplifiers to the first port of the multi-port network.

Preferably, the method further includes setting the phase relationship of the plurality of transmission signals to direct a majority of the transmission signal power to a selected subset of multiple antennas.

Preferably, the method further includes directionally coupling the transmitted signal through a directional coupler, wherein the antenna is connected to a corresponding one of the plurality of second ports through the directional coupler.

Preferably, the method further includes a coupling output of a directional coupler connected to the transmission signal processing circuit, and the transmission signal processing circuit adjusts at least one of the phase and amplitude of the transmission signal based on the coupled signal of the coupling output.

Preferably, the method further includes directionally coupling the transmission signal through a directional coupler, wherein the power amplifier is connected to a corresponding one of the plurality of first ports through the directional coupler.

Preferably, the method further includes a coupling output of a directional coupler connected to the transmission signal processing circuit, and the transmission signal processing circuit adjusts at least one of the phase and amplitude of the transmission signal based on the coupled signal of the coupling output.

From the following detailed description, other aspects and advantages of the described embodiments are obvious It is easy to see that, in conjunction with the drawings, the principles of the embodiments are explained by way of examples.

<p>110Multi-port network</p><p>21090 Degree Hybrid Coupler</p><p>312, 314Power amplifier</p><p>410Transmitting signal conditioning circuit</p><p>512, 514Transmit/Receive Switch</p><p>522,524Low noise amplifier</p><p>612, 614directional coupler</p><p>1010Transmit signal processing block</p><p>1020RF up-conversion block</p><p>1032,1034Down Frequency Switcher</p><p>1042, 1044Received signal processing</p><p>1050Switch</p><p>1060Power Detector</p><p>1110Multi-port network</p><p>1212,1214Switch</p><p>1222, 122490 Degree Hybrid Coupler</p>

Figure 1 shows a block diagram of an embodiment of a transceiver including a multi-port network and multiple antennas; Figure 2 shows an embodiment of a multi-port network; A block diagram of an embodiment of an antenna; Figure 4 shows a block diagram of an embodiment including multiple power amplifiers, a multi-port network, multiple antennas, and a transmission signal phase and/or amplitude adjustment circuit; Figure 5 shows the implementation of a transceiver A block diagram of an example, the embodiment includes multiple power amplifiers, multi-port networks, transmit/receive switches, low noise amplifiers, and multiple antennas; Figure 6 shows a block diagram of an embodiment of the transceiver, the implementation Examples include multiple power amplifiers, directional couplers, multi-port networks, transmit/receive switches, low noise amplifiers, and multiple antennas; Figure 7 shows a block diagram of an embodiment of the transceiver, the embodiment includes multiple Power amplifier, multi-port network, directional coupler, transmit/receive switch, low noise amplifier, and multiple antennas; Figure 8 shows a block diagram of another embodiment of the transceiver, the embodiment includes multiple power amplifiers , Transmit/receive switch, low noise amplifier, directional coupler, multi-port network, and multiple antennas; Figure 9 shows a block diagram of another embodiment of the transceiver, the embodiment includes multiple power amplifiers, multiple Port network, directional coupler, transmit/receive switch, low noise amplifier, and multiple antennas; Figure 10 shows a block diagram of an embodiment of the transceiver, the embodiment includes transmit and receive signal processing, multiple power Amplifier, directional coupler, multi-port network, transmit/receive switch, low noise amplifier, and multiple antennas; Figure 11 shows a block diagram of an embodiment, the embodiment includes multiple power amplifiers, multi-port network , And more than two antennas; FIG. 12 shows a block diagram of an embodiment that uses multiple power amplifiers and multiple quadrature hybrid couplers; FIG. 13 shows a flowchart of the steps of an embodiment of a method of operating an amplifier, the embodiment Including multi-port networks.

The embodiments include systems, methods, and devices of a transceiver architecture that includes a multi-port network and multiple antennas.

FIG. 1 shows a block diagram of an embodiment of a transceiver architecture including a multi-port network 110 and multiple antennas. The multiple antennas include antenna 1 to antenna M. As shown in the figure, the multi-port network includes N input ports and M output ports. Each antenna M is connected to an independent output of the multi-port network. When transmitting, each of the N input ports is driven by the corresponding transmitting signal. As will be described, the transmitted signal can be pre-processed before being input to the multi-port network, wherein the pre-processing adjusts the amplitude and/or phase of the transmitted signal. Although the multiport network 110 is described as having N inputs and M outputs, any subset of the inputs and outputs can be utilized. Here, the terms input and output are used to clarify the operation of a multi-port network. Understandably, a multiport network is a two-way device; this attribute will obviously be used in the discussion of Figure 8. In Figure 1, the ports are more generally labeled as a first port and a second port.

The scattering parameter (S parameter) describes the amplitude ratio of the output to the input of a linear grid. S-parameters are unit-less complex numbers that vary with frequency, which can represent gain and phase. The S-parameter matrix describing the N-port network is an n-dimensional square matrix.

The S-parameter matrix of the two-port network is generally used to describe the relationship between the reflected and incident power waves, according to:<maths><img file="TWI474651B_D0001.tif" he="217" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="629" /></maths>, Here, O₁And O₂For output, I₁And I₂For input, equivalent to O₁=S₁₁I₁+S₁₂I₂And O₂=S₂₁I₁+S₂₂I₂. The transfer function of the multi-port network 110 can be represented by an S-parameter matrix.

Figure 2 shows an embodiment of a multi-port network, which is commonly referred to as a 90-degree hybrid coupler. For this exemplary embodiment, consider port 1 and port 2 as input, and port 3 and port 4 as output. Using the transmission lines with electrical lengths and impedance characteristics, a 90-degree hybrid coupler 210 can be realized. Here, Z₀The impedance characteristic expressed is usually 50 ohms; λ/4 is a quarter-wavelength line at the center frequency of the emission.

The nominal scattering parameter of the 90-degree hybrid coupler is given by:<maths><img file="TWI474651B_D0002.tif" he="350" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1379" /></maths>

make<img file="TWI474651B_D0003.tif" he="144" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="157" />Is a mixed input, where x₁Indicates the signal applied to port 1, x₂, Indicates the signal applied to port 2. Similarly, let<img file="TWI474651B_D0004.tif" he="126" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="172" />Is a mixed output, where y₁Indicates the signal appearing at port 3, y₂Indicates the signal appearing on port 4. Using formula (1), the nominal relationship between the vector of input x and the vector of output port y is given by y=Ax, where:<maths><img file="TWI474651B_D0005.tif" he="216" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1570" /></maths>

The 90-degree hybrid coupler 210 is a time invariant non-ferromagnetic passive circuit. It is assumed that the impedance seen through the multiple ports of the degree hybrid coupler 210 is nominal. Then, maintain the following voltage relationship: x=A^TyC² ， (3)

Among them, C represents the complex number domain. Therefore, based on the above assumptions, the 90-degree hybrid coupler is a two-way device, and the transfer function from one port to another does not depend on which is the input and which is the output.

Figure 3 shows a block diagram of an embodiment of a transceiver. The transceiver includes multiple transmitters Radio input signal (In₁...In_N), power amplifiers 312 and 314, multi-port network 110, and multiple antennas (antenna 1, antenna M). As an example, the transmission input signal is amplified by the power amplifiers 312 and 314 and used for the first ports of the multi-port network 110. The multiple transmitting antennas from antenna 1 to antenna M are connected to multiple second ports of the multi-port network 110. An example of a multi-port network is a 90-degree hybrid coupler 210.

The embodiment includes preprocessing the transmitted input signal to establish a phase relationship between the amplified signals received by the multi-port network 110. The phase relationship can be selected to produce an improved signal-to-noise ratio (SNR) at the base station (BS) to which the transceiver (e.g., user) communicates. In a time division duplex (TDD) system, the signal-to-noise ratio of the base station can be predicted from the received downlink signal; that is, the signal received from the user when the transmission signal from the base station is received.

In addition, the phase relationship can be adjusted in response to requests from the base station. On the basis of frequency selectivity, the phase relationship can be selected. For example, in an OFDM (Orthogonal Frequency Division Multiplexing) system including a plurality of subcarriers, the phase can be adjusted on a subcarrier-by-subcarrier basis. In a preferred embodiment, a common phase relationship can be used for all sub-carriers. Additionally or preferably, the phase relationship can be dynamically adjusted.

For one embodiment, the selection of the phase relationship combined with the multi-port network essentially leads to the selection of a transmitting antenna (antenna 1 to antenna M) in which most of the transmitted signals are directed. power. As mentioned above, there is no limit to the number of antennas, and there is no limit to the number of antenna subsets for directional signal power. As described above, the antenna selection can be made adaptively on the subcarriers and time (symbols) of the multi-carrier signal.

For another embodiment, the selection of phase and amplitude combined with the multi-port network 110 essentially results in the formation of beamforming signals on the output of multiple antennas. As mentioned above, there is no limit to the number of antennas. As described above, the antenna selection can be made adaptively on the subcarriers and time (symbols) of the multi-carrier signal.

For an embodiment, the multi-port network 110 may be a 90-degree hybrid coupler 210, as shown in Figure 2. In this embodiment, the ports 1 and 2 of the multi-port network are connected to the output terminals of the power amplifiers 312 and 314, respectively. Ports 3 and 4 of the multi-port network are connected to antenna 1 and antenna 2 respectively.

For the purpose of explanation, it is assumed that both the power amplifier 312 and the power amplifier 314 have a complex gain g=ke^{j θ}, And the 90-degree hybrid coupler has a matrix transfer function given by equation (2). Let x₁(f)=w₁s(f)ε C², Represents the vector signal applied to the input of the power amplifier, where,<maths><img file="TWI474651B_D0006.tif" he="256" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1664" /></maths>

Represents the weight vector and S(f) is a frequency selective signal. In this case, the output vector of the 90-degree hybrid coupler 210 is:<maths><img file="TWI474651B_D0007.tif" he="406" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1161" /></maths>

It can be seen that all the power is applied to antenna 1, and this power is twice the power of the signal generated by each power amplifier. Similarly, if the vector signal applied to the power amplifier is determined by x₂(f)=w₂s(f)ε C²Given while<maths><img file="TWI474651B_D0008.tif" he="199" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1500" /></maths>

The final output vector of the 90-degree hybrid coupler is:<maths><img file="TWI474651B_D0009.tif" he="406" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1304" /></maths>

In this case, all power is applied to antenna 2. For clarity, in The losses and imbalances in mixing have been ignored in the previous discussion. In practice, these losses and imbalances will be considered and compensated.

For a general multi-port network, the vector signal at its input can be written as: x(f)=w(f)s(f) (8)

Two situations need to be considered. In the first case, w(f)ε C^NIt is a weight vector dependent on frequency (or subcarrier index) f and s(f)ε C is equivalent to a modulated signal. The weight vector W(F) has a dimension equal to the number of input terminals of the multi-port network. In the second case, w(f)ε C^N×LIs a weight matrix, s(f)C^LCorresponds to the vector of the modulated signal, and L is the number of spatial streams. It can be understood that although the signal is represented in the frequency domain, it is expected that the signal will be switched to the time domain before transmission.

Figure 4 shows an embodiment of a block diagram of a transceiver. The transceiver of this embodiment includes a transmission signal conditioning circuit 410, multiple power amplifiers 312 and 314, a multi-port network 110, and multiple antennas. The transmission signal adjustment circuit 410 is used to adjust the modulation signal s(f)ε C^LThe phase and/or amplitude of and the multiple outputs applied to the power amplifiers 312 and 314 are generated. The transmission signal adjustment circuit corresponds to the weight vector or matrix w(f) of equation (8). The number L of spatial streams can be one or more than one. For an embodiment, the transmission signal adjustment circuit 410 is implemented by a signal processing circuit. The signal processing circuit can dynamically adjust the amplitude of each transmitted signal and the phase relationship between the transmitted signals. For example, in another embodiment, the transmission signal adjustment circuit 410 is implemented by a signal processing circuit. The signal processing circuit generates a transmission signal that has a fixed amplitude relationship and a phase relationship between the dynamically adjustable transmission signals. For example, in another embodiment, a multi-port network is used to implement the transmission signal conditioning circuit. For example, in another embodiment, a 90-degree hybrid coupler is used to implement the transmission signal adjustment circuit; this embodiment is further described in the discussion of FIG. 12.

Figure 5 shows an embodiment of a block diagram of a transceiver. The transceiver includes multiple power amplifiers 312, 314, a multi-port network 110, transmit/receive switches 512, 514, low noise amplifiers 522, 524, and multiple antennas. In this embodiment, the switches 512 and 514 are connected to the multiple second ports of the multi-port network 110 and one of the antennas (antenna 1, antenna M) between. The switch can be used to provide a receiving path without passing through the multi-port network 110. As mentioned above, the switch is also connected to the Rx for generating the received signal₁, Rx_MThe low-noise amplifiers 522 and 524 are used to process the received signal after down-conversion.

In an embodiment, the signals In1 and InN applied to the power amplifiers 312, 314 can be controlled so that the main transmission power appears on one of the antennas, where the amplitude of the received signal is the maximum. In another embodiment, the signal may be processed so that most of the transmit power at each frequency is used for the antenna, and the received signal strength indicator (RSSI) of the antenna is the largest. In another embodiment, on the basis of frequency selectivity, the signal applied to the power amplifiers 312, 314 causes most of the power to be transmitted to one or the other antenna, and the selection is based on which antenna has a stronger frequency suitable for the frequency receive signal.

FIG. 6 shows an embodiment of a block diagram of another transceiver. The transceiver includes a plurality of power amplifiers 312, 314, a plurality of directional couplers 612, 614, a multi-port network 110, and a multiple transmit/receive switch 512 , 514, multiple low noise amplifiers 522, 524, and multiple antennas.

The first switching settings of the transmit/receive switches 512 and 514 connect the antenna to a plurality of second ports of the multi-port network 110. The first handover setting, as shown in FIG. 6, is used when the user station is transmitting. Use this second switching setting when the user station is receiving, connect the antenna to the low noise amplifiers 522, 524 for generating output Rx₁, Rx_M, The output is then down-converted and processed. In addition, the directional couplers 612, 614 redirect a small amount of power to generate a feedback signal Fb to help preprocessing the transmitted signal._J, Fb_N. As shown, the directional couplers 612, 614 are located between the power amplifiers 312, 314 and the first setting of the ports of the multiport network 110. At the input of the multiport network, the coupler allows the measurement of the amplitude and phase of the transmitted signal. In an embodiment, the feedback signal Fb at the output of the directional coupler_J, Fb_N, There is a power level of about 18 decibels lower than the power level input to the directional coupler, the feedback signal Fb_J, Fb_NUsed to help the preprocessing of the transmitted signal.

Figure 7 shows an embodiment of a block diagram of a transceiver. The transceiver includes a plurality of Power amplifier, multi-port network, directional coupler, transmit/receive switch, low noise amplifier, and multiple antennas. Fig. 7 is similar to Fig. 6, but the order of the multiport network 110 and the directional couplers 612, 614 is reversed. In this embodiment, the output of the multi-port network is connected to the feedback signal Fb through the directional couplers 612 and 614₁, Fb_N. This allows the transmission signal processing to correct any un-modeled or uncharacterized operating conditions of the multi-port network 110, thereby reducing adjustment requirements and if any un-modeled, or uncharacterized operating conditions of the multi-port network 110 Or the robustness of non-characteristic operating conditions.

Figure 8 shows an embodiment of a block diagram of another transceiver. The described embodiment includes multiple power amplifiers 312, 314, transmit and receive switches 512, 514, low noise amplifiers 522, 524, directional couplers 612, 614, multi-port networks, and multiple antennas. This embodiment includes directional couplers 612, 614, which connect a small portion of the transmission signals appearing in the first ports of the multi-port network 110, and the multi-port network can be used to help transmit Signal preprocessing. In addition, the switches 512 and 514 provide the receiving signal path to the low noise amplifiers 522 and 524. In this embodiment, the signals received by the multiple receiving antennas pass through the multi-port network 110.

During the reception using port 1 connected to the directional coupler 612 and port 2 connected to the directional coupler 614, the power of the ports 1 and 2 of the multi-port network is The pressure vector is<img file="TWI474651B_D0010.tif" he="126" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="344" />. In Figure 8, like X₁And X₂Same, mark more separately Port 1 and Port 2 of network 110. make<img file="TWI474651B_D0011.tif" he="129" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="337" />Means the same during launch The voltage vector of the port. Similarly, let the voltage vectors of ports 3 and 4 of the multi-port network be<img file="TWI474651B_D0012.tif" he="139" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="409" />, When here, port 3 is connected to antenna 1 and port 4 is connected to antenna 2; In Figure 8, like y₁And y₂Same, mark them separately. make<img file="TWI474651B_D0013.tif" he="120" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="347" />For The voltage vector of the same port during transmission. (Again) Suppose that the multi-network 110 is a linear and time-invariant non-ferromagnetic passive circuit, and the impedance seen from the multi-port network 110 is nominal, maintaining the following voltage relationship:<maths><img file="TWI474651B_D0014.tif" he="181" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1720" /></maths>

as well as<maths><img file="TWI474651B_D0015.tif" he="152" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1746" /></maths>

Among them, AC^2×2Is the scattering parameter matrix. make<img file="TWI474651B_D0016.tif" he="119" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="69" />(f, t)C²It is a vector channel from the base station to ports 3 and 4 of the multi-port network 110. After passing through the multi-port network, the apparent receiving channel is given by:<maths><img file="TWI474651B_D0017.tif" he="152" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1783" /></maths>

in,(.)^TRepresents transpose. When time is t_Rx,make<img file="TWI474651B_D0018.tif" he="91" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="431" />And respectively represent the phase vector values of port 1 and port 2 by the frequency indicator_indexed. Here, it represents the angle operator, and t_RxCorresponds to the time interval of the downlink sub-frame, during which the receiver obtains the phase measurement result. Similarly, when time is t_Tx, Define and respectively represent the vector value of the phase indicated by the frequency of port 1 and port 2, during which time the user transmits a signal.

In one embodiment, the user can control the phase relationship of the transmitted signal, when the transmission interval t_TxSatisfy the relationship:<maths><img file="TWI474651B_D0019.tif" he="122" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="843" /></maths>

In other words, at each frequency, the transmit phase difference between antennas is the negative of the receive phase difference. The transmitter estimates the weight vector:<maths><img file="TWI474651B_D0020.tif" he="335" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1354" /></maths>

To create an uplink signal w(f, t_Rx)m(t). The output of the power amplifier passes through the transmit/receive switches 512, 514 and the directional couplers 612, 614 to generate a vector signal on the 110 multi-port network:<maths><img file="TWI474651B_D0021.tif" he="116" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1490" /></maths>

Here, α is a complex constant (complex constant) related to phase and amplitude, and the phase and amplitude are the common phase and amplitude of the transmitted signal in the multi-port network 110. The output of the multiport network 110 is given by:<maths><img file="TWI474651B_D0022.tif" he="140" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1583" /></maths>

make<img file="TWI474651B_D0023.tif" he="93" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="510" />Represents the upstream channel. The final uplink signal received at the base station is given by:<maths><img file="TWI474651B_D0024.tif" he="268" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1596" /></maths>

Since the values of time and frequency are the same, the uplink and downlink channels are reciprocal; which is<img file="TWI474651B_D0025.tif" he="76" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="536" />. Since the transmitted signal t_TXSufficiently close to receive the measurement Time t_RX, And sufficiently low mobility<img file="TWI474651B_D0026.tif" he="85" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="386" />. These conditions are generally considered to exist In the TDD cellular network.

considering<img file="TWI474651B_D0027.tif" he="85" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="335" />, The benefits of this embodiment can be understood. The effective channels visible to the receiver are given by:<maths><img file="TWI474651B_D0028.tif" he="228" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1435" /></maths>

The transmission weight vector is given by:<maths><img file="TWI474651B_D0029.tif" he="322" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1341" /></maths>

The transmitted signal on the output of the multi-port network is given by:<maths><img file="TWI474651B_D0030.tif" he="614" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1391" /></maths>

Where m(t) is the modulated signal. The signal received at the base station is given by:<maths><img file="TWI474651B_D0031.tif" he="235" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1454" /></maths>

Compared with the case without a hybrid circuit, the voltage gain is equivalent to within |A11|+|A12|. The |A11|+|A12| consists of one or two power amplifiers that do not include a hybrid circuit. Realized by emitting the same power. For nominal 90 degree hybrid coupler<img file="TWI474651B_D0032.tif" he="114" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="596" />And the achieved gain is equal to 3dB, If the strategy is selected with the same weight,<img file="TWI474651B_D0033.tif" he="95" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="303" />, Using the same configuration, the signal received from the base station is given by:<maths><img file="TWI474651B_D0034.tif" he="222" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1452" /></maths>In this case, the voltage gain of |A11|+|A12| is achieved by comparing with not using a multi-port network to transmit the same power on each antenna. The selection of the gain of the transmission phase relationship according to formula (12) is not limited to the case where there is a strong imbalance between the amplitude of the received signal. In another embodiment, the common phase difference between the transmitted signals is used for all frequencies.

Generally, the amplitude and phase difference existing in the transmit RF path is caused by one or more of the following reasons: electrical delays, temperature, frequency, and calibration errors. Signal Fb₁And Fb₁It is the feedback signal that is subsequently processed and used to control the amplitude and or phase of the transmitted signal. In an embodiment, the feedback signal is associated with the transmission signal m(t). In another embodiment, the power appearing on the feedback signal can be measured.

Use digital signal processing technology to down-convert, digitize, and process the low-noise amplifier to generate the phase of the received signal<img file="TWI474651B_D0035.tif" he="79" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="272" />as well as<img file="TWI474651B_D0036.tif" he="83" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="337" />。

In another embodiment, the calibration signal is applied to the signal Fb₁And Fb₂. These calibration signals are coupled through the directional couplers 612 and 614 and the transmitting and receiving switches 512 and 514 to the inputs of the low noise amplifiers 522 and 524. The calibration signals can be down-converted and amplified and then processed to measure the delay from each directional coupler 612, 614 to the output of the respective digital signal processing. The measured phase delay is used to compensate the measured phase of the received signal.

Figure 9 shows an embodiment of a block diagram of a transceiver. This embodiment includes multiple power amplifiers 312 and 314, a multi-port network 110, multiple antennas, switches 512 and 514, and directional couplers 612 and 614. In this embodiment, the multi-port network is part of the transmission path but not part of the reception path. The directional couplers 612, 614 are connected to the antenna. Coupling is applied to part of the transmitted signal of antenna 1 and antenna 2, and the feedback signal Fb is generated through directional couplers 612 and 614₁And Fb₂. Then process the Fb₁And Fb₂To measure the phase of the signal emitted by each antenna. In one embodiment, through the low noise amplifiers 522 and 524, the receiving path, and the digital signal processing, these feedback signals are applied to the directional couplers 612 and 614 with calibration signals, so that the phase delay of the directional couplers 612 and 614 is measured as possible.

This embodiment provides benefits in situations where the interference level that occurs at each receiving antenna is substantially different. Considering this situation, where the expected received signals on the two antennas have comparable power, strong interference may appear at the first antenna instead of the second antenna. In this case, using an optimal receiver that receives signals through a multi-port network is not as good as working without a multi-port network as the receiving path. Using multiple measurement results, the embodiment in FIG. 9 makes it possible to adjust the parameter specifications of the transmission path, the reception path, and the multi-port network.

Figure 10 shows an embodiment of a radio frequency circuit. The radio frequency line is connected to a power amplifier in an Orthogonal Frequency Division Multiplexing (OEDM) system, where the transmission (Tx) data s(f) is applied to The input of the signal processing block 1010 is transmitted. A radio frequency up-convert block processes and up-converts the signal. Up-converting the signal x generated by the power amplifiers 312 and 314 of the transmission signal₁And x₂Zoom in, the x₁And x₂Used for the input of the hybrid coupler 210. Through the directional couplers 612 and 612 and the transmitting/receiving switches 512 and 514, the mixed output channel is connected to the antenna 1 and the antenna 2.

The additional outputs of the directional couplers 612, 614 are coupled to a switch 1050 selected from among the additional outputs. The selected additional output is applied to the power detector 1060, which generates a power sense signal, which represents the output power on the corresponding antenna. The power detector may be useful for controlling the amplitude and phase of the signal, which refers to the signal applied to the power amplifiers 312 and 314.

When a signal is received, the switches 512 and 514 control the received signal to be used in the low noise amplifiers 522 and 524. The received data signal is generated by the down-converter 1032, 1034, the down-converter down-converts the received signal, and the received signal processing 1042, 1044 down-converts the received signal.

An embodiment includes at least one dynamically adjustable phase shift signal generated by dynamically adjusting at least one phase relationship of the transmitted signal. That is, the second signal is generated from the dynamically adjustable signal, and the second signal has a phase different from the transmitted signal. The amplitude of the second (or more) signal may be different from the transmitted signal due to a variety of reasons including amplitude imbalance in radio frequency circuits and multi-port networks.

An embodiment includes, on the basis of frequency selectivity, when the adjustment of at least one phase relationship between the transmitted signal and the at least one dynamically adjustable phase shift signal is determined, controlling most of the signal power of the combined signal for multiple transmissions Part of the antenna. This method may include deciding on the receiving antenna and selecting the antenna for transmission, which has the strongest received signal. For this embodiment, without the need for physical switches and applying signal energy to the required antenna, the required antenna (or the required multiple antennas) can be effectively selected (multiple signal powers are applied to). In the multi-port network Radio signals and dynamically adjustable phase-shifted signals, as well as the phase relationship between the combinations of these signals, lead to the application of combined signal energy to a subset of multiple antennas.

An embodiment includes a subset of multiple antennas, and most of the signal power of the combined signal is adaptively directed to the subset, and the subset can be dynamically and adaptively selected over time.

An embodiment includes a transmission signal and at least one dynamically adjustable phase shift signal that is a multi-carrier signal. Each multi-carrier signal includes multiple sub-carriers. Further, this embodiment may include a part of multi-antenna adaptive control of the signal power of the combined signal based on sub-carrier-sub-carrier. The subcarrier-subcarrier signal power direction can be determined by the adjustment of at least one phase relationship between the transmitted signal and the at least one dynamically adjustable phase shift signal.

For example, in one embodiment, the multi-port network includes a hybrid coupler that combines the amplified transmission signal and the amplified at least one dynamically adjustable phase shift signal, and generates an output signal for each of the multiple antennas. More generally, a multi-port network includes a combined amplifying transmission signal. The amplifying transmission signal includes delaying each amplified transmission signal before combining to generate multiple combined outputs, the output corresponding to each of the multiple antennas, where the delay is preset .

An embodiment includes controlling the phase relationship between the transmission signal and the at least one dynamically adjustable phase shift signal based on characterizing the quality of the transmission channel associated with each of the plurality of antennas. That is, the adaptive selection of the subset of the multiple antennas that locates the power of the combined signal is based on the characterized channel quality. For example, in an embodiment, the transmission channel quality is characterized across subcarriers of the multi-carrier signal. For example, an embodiment includes characterizing the quality of the transmission channel based on the reception of a signal through each antenna.

The transmission may include calculation tiles including multiple sub-carriers of multiple multi-carrier symbols. One implementation includes selecting a subset of multiple antennas where most of the signal power of the combined signal is oriented based on a tile-by-tile basis.

For an embodiment, the transmit channel quality associated with each antenna includes a preamble that characterizes a downlink sub-frame from at least one received signal (preamble) pilot. For example, in a specific embodiment, the pilot of the preamble is characterized based on the sub-carriers of the preamble corresponding to a group of sub-carriers to be allocated during transmission. For example, in a specific embodiment, the pilot that characterizes the preamble appears in the entire subcarrier range, and the subcarrier overlap is to be allocated to a subset of multiple antennas during transmission. According to the received signal quality of the characterized pilot, the signal power of the sub-carrier group of the multi-carrier signal is directed to the subset of the multiple antennas.

The base station receiving signal processing may include, for example, maximum load (UL) channel estimation. In order to reduce the influence of additional noise and interference, this channel estimation is usually the average value of the pilots of a group of adjacent subcarriers. In general, the channel from the user station antenna to the base station antenna is different in amplitude and phase. In order to eliminate channel estimation errors due to averaging at the base station, embodiments may include avoiding separation of subcarrier groups across user antennas. For the WiMAX system, a useful sub-carrier grouping includes, for example, the partial use of sub-channels (PUSC) maximum load calculation block, where PUSC stands for partial sub-channels, the physical in the third-generation cooperation project The resource block (PRB) long-term evolution standard is another useful subcarrier grouping.

On the basis of calculation block-calculation block, it is beneficial to allocate different transmission phases. Therefore, the upper limit calculation block covers a narrow frequency range. Therefore, the channel is generally only a small amount in the calculation block and channel that spans all the sub-carriers in the group that can be effectively characterized by a single metric. In addition, during the maximum load sub-frame, the set of calculation blocks constituting the sub-channel will not change. On subsequent symbols, this allows the calculation block to be allocated to independent antennas without affecting subsequent allocation, which may result in the same calculation block being sent on different antennas with different symbols. This is true, even in the following situations, for example, sub-channel loops, the Global Interconnection for Microwave Access System. The sub-channel loop complies with section 8.4.6.2.6 of the IEEE 802.16 standard. Other useful sub-carrier groups include automatic modulation control band receivers in the Global Interconnection for Microwave Access Standards, and so on.

FIG. 11 shows an embodiment of a multi-port network including multiple multi-port networks. In this case, the number of transmitter paths and the number of antennas are greater than two. Let x=(x₁x₂x₃x₄ ]^TRepresents the input vector to the multiport network 1110, and let y=[y₁y₂y₃y₄ ]^T<img file="TWI474651B_D0037.tif" he="63" img-content="character" img-format="tif" inline="no" orientation="portrait" wi="42" />C⁴Represents the output vector. Assume that the matrix transfer function of the hybrid coupler 210 is defined in (2). Then, x=[x₁x₂x₃x₄ ]^TThe relationship between is y=<i>H</i>x is given, where<maths><img file="TWI474651B_D0038.tif" he="382" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1416" /></maths>

The matrix H is full rank, single, and all rows have a constant factor l₁. Therefore, it is always possible to choose points x₁...x₄, So that all the power is transferred to any antenna used for single layer spatial transmission. It is also possible to deliver all the power to any two antennas for spatial rate 2 transmission.

Fig. 12 shows a block diagram of an embodiment of a transceiver that includes a plurality of switches 1212, 1214, a plurality of 90-degree hybrid couplers 1222, 1224, a plurality of power amplifiers 312, 314, and multiple antennas. The switches 1212 and 1214 are controlled by a common signal. The switches 1212, 1214, and the hybrid coupler 1222 together are equivalent to the transmission signal phase adjustment circuit, as described above. Let x₁And x₂Represents the output of the hybrid coupler. Accompanied by the hybrid coupler shown in Equation 2 and the switches 1212 and 1214 at the positions, the output of the hybrid coupler 1222 is given by the following equation:<maths><img file="TWI474651B_D0039.tif" he="206" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1590" /></maths>

The output result of the hybrid coupler 1224 is given by:<maths><img file="TWI474651B_D0040.tif" he="248" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1537" /></maths>

The power of all power amplifiers is considered suitable for antenna 2. Similarly, if the switches 1212 and 1214 are placed in the opposite positions shown in Figure 12,<maths><img file="TWI474651B_D0041.tif" he="231" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1582" /></maths>And the output result of the hybrid coupler 1224 is given by the following formula:<maths><img file="TWI474651B_D0042.tif" he="247" img-content="drawing" img-format="tif" inline="no" orientation="portrait" wi="1622" /></maths>In this case, all power is applied to antenna 1.

Compared to output y₁And y₂Choose between, using this method to select the transmitting antenna is more appropriate. Overcoming the embedded loss of about 0.5 decibels of the switch requires a predictable increase in power consumption. For signals that are switched before the power amplifier, the increase in power consumption will be reduced.

Figure 13 shows a flow chart including the steps of implementing a method of operating a transceiver that includes a multi-port network. The first step 1310 includes coupling multiple transmit signals to multiple first ports of the multi-port network. The second step 1320 includes connecting multiple second ports to multiple antennas of each multi-port network, wherein at least one of the second ports responds to at least two of the first ports.

For example, in an embodiment, the method further includes at least part of the received signal based on the characterization, and setting at least one of the plurality of transmitted signals by controlling at least one phase and amplitude of the transmitted signal of at least one of the multi-port networks Phase and amplitude to form at least one output transmit signal. The transmission signal passes through the multi-port network.

The method further includes coupling a plurality of output power amplifiers to the first port of the multi-port network. A more specific embodiment includes, by setting the phase relationship of multiple transmitted signals, directing most of the transmitted signal power to a selected subset of multiple antennas.

The method further includes directionally coupling the transmitted signal through a directional coupler, wherein, through the directional coupler, the antenna is connected to a corresponding one of the plurality of second ports. A more specific embodiment includes a coupling output of a directional coupler connected to the transmission signal processing circuit, and the transmission signal processing circuit adjusts the phase and amplitude of at least one transmission signal based on the coupled signal of the coupling output.

In an embodiment, the method further includes directionally coupling the transmission signal through a directional coupler, wherein the power amplifier is connected to a corresponding one of the plurality of first ports through the directional coupler. A more specific embodiment includes the coupling output of a directional coupler connected to the transmission signal processing circuit, and the transmission signal processing circuit adjusts the phase and amplitude of at least one transmission signal based on the coupled signal of the coupling output.

Although specific embodiments have been described and illustrated, the embodiments are not limited to the specific forms and arrangements described and illustrated above.