Multi-port, multi-antenna element mobile phone millimeter-wave antenna system

Abstract

This invention discloses a millimeter-wave antenna system for mobile phones, comprising: multiple antenna elements, each antenna element providing a port; multiple mixing units, each used to perform a mixing process on the output signal of its port; multiple analog-to-digital converter units, used to correspondingly perform an analog-to-digital conversion on the output signals of the mixing units to generate multiple baseband digital signals; and a baseband signal processor having multiple weighting function modules and a summing function module, wherein the weighting function modules are used to multiply each of the baseband digital signals by a corresponding weighting function, and the summing function module is used to sum the output values ​​of the weighting function modules.

Description

Technical Field

[0001] This invention relates to the field of wireless communication, and in particular to a millimeter-wave antenna system for mobile phones. Background Technology

[0002] The fifth-generation mobile communication system (5G) includes two frequency bands: FR1 (sub 6G) and FR2 (Millimeter Wave). 5G mobile phones utilize these two frequency bands for communication. Millimeter-wave mobile phone antennas typically use microstrip antennas (patch antennas). Currently, mobile phone millimeter-wave antennas use several array antennas, each with four antenna elements. Each antenna element is connected to a phase shifter. By adjusting the phase of each antenna element's phase shifter, the radiation pattern of the array antenna is concentrated in a specific direction. Each array can be individually beamformed to its optimal state, and then the best array is selected from several arrays for uplink and downlink data transmission.

[0003] Because each antenna element is connected to a phase shifter, which introduces 2-3 dB of insertion loss. In addition, a selection switch is needed to select an array from several arrays, which introduces another 1-2 dB of insertion loss.

[0004] Insertion loss, besides reducing signal level, also generates additional heat and consumes more power from the phone's battery. Furthermore, since each antenna array consists of four antenna elements, and each antenna array occupies four times the space of individual antenna elements, placing multiple antenna arrays on a phone is less flexible than placing multiple individual antenna elements. Additionally, in terms of antenna-on-chip (AOP) technology, integrating antenna elements on a chip is much easier than integrating antenna arrays.

[0005] In existing array antenna schemes, the signal processing method for each antenna element involves multiplying the received signals of each element by their phase and then combining them. This combination is performed at the radio frequency (RF) end, and the phase multiplied by each sub-frequency component of the received signal is the same. Additionally, a selection switch is provided at the RF end to select the optimal array from multiple arrays. Furthermore, the single-port hardware components (phase shifters and switches) at the RF end cannot effectively compensate for individual frequency components, thus their output may experience severe attenuation at certain frequency components, thereby reducing the overall transmission performance of the signal band.

[0006] To address the aforementioned issues, there is an urgent need in this field for a novel multi-port, multi-antenna element millimeter-wave antenna system for mobile phones.

[0007] Furthermore, 5G millimeter wave technology features multiple input multiple output (MIMO) specifications, enabling the simultaneous transmission of multiple independent data sets, while existing single-port multi-array antenna architectures can only transmit one set of data at a time. In contrast, this invention employs a multi-port architecture, which, in conjunction with the base station's multi-port antenna architecture, can transmit up to four different sets of data simultaneously, thus significantly improving the transmission capacity of wireless communication systems. Summary of the Invention

[0008] The main objective of this invention is to provide a multi-port, multi-antenna element millimeter-wave antenna system for mobile phones, which can significantly reduce the area occupied by the antenna system on the printed circuit board by providing one port through a single patch (microstrip antenna). In addition, since a single microstrip antenna occupies little space, its placement is extremely flexible, and it can be placed on the surface of the narrow bezel of the mobile phone and on the back of the circuit board, unlike array antennas (containing four microstrip antennas) which have more limited placement options.

[0009] Furthermore, current mobile phone millimeter-wave antenna systems have several array antennas, each consisting of four antenna elements, and each antenna element is connected to a phase shifter to change the phase. The phase shifter introduces a 2-3 dB insertion loss. Additionally, because current mobile phone millimeter-wave antenna systems select the optimal array antenna for both transmission and reception from among several array antennas, a selection switch is required. This selection switch introduces a 1-2 dB insertion loss, resulting in a decrease in signal level, additional heat generation, and increased battery drain. In contrast, the antenna system of this invention has neither a phase shifter nor a selection switch, thus avoiding the aforementioned problems of current mobile phone millimeter-wave antenna systems.

[0010] Furthermore, this invention is particularly suitable for indoor environments with multipath waves and situations where direct waves are blocked by the human body. When direct waves are blocked by the human body, and the incoming wave to the mobile phone lacks a dominant wave, the beamforming function of the array antenna becomes less effective, and the interference between multipath waves causes signal attenuation at different frequencies. This invention uses a multi-port architecture, where each frequency component of the signal at each port is sampled and fed into the baseband signal processor, where each frequency is effectively combined individually, thus effectively eliminating the aforementioned attenuation phenomenon.

[0011] In addition, the microstrip antenna element architecture used in this invention is easily integrated onto a chip using the newly developed Antenna on Chip technology.

[0012] In addition, although each port of the present invention requires a transceiver module, which increases the space occupied by the circuit and the cost, the technology of transceiver modules is already mature and multiple modules can be integrated on the same chip, so the increase in space and cost is limited.

[0013] To achieve the aforementioned objectives, a mobile phone millimeter-wave antenna system is proposed, comprising:

[0014] Multiple antenna elements, each providing one port;

[0015] Multiple mixing units, each used to perform a mixing process on the output signal of the port;

[0016] Multiple analog-to-digital converter units are used to correspondingly perform analog-to-digital conversion on the output signals of these mixer units to generate multiple baseband digital signals; and

[0017] A baseband signal processor has multiple weighting function modules and a summing function module, wherein the weighting function modules are used to multiply each of the baseband digital signals by a corresponding weighting function, and the summing function module is used to sum the output values ​​of the weighting function modules.

[0018] In one embodiment, the mixing process is an OFDM signal processing.

[0019] In one embodiment, the antenna element is a microstrip antenna.

[0020] In one embodiment, the weight function corresponding to the m-th port is expressed as shown in formula (1):

[0021]

[0022] Among them, w m (ω q ) represents the weighting function, ω q H represents the q-th subcarrier. m (ω q ) represents the m-th antenna element at a subcarrier frequency of ω. q Channel response at that time.

[0023] In one embodiment, the output formula of the summing function module is shown in formulas (2), (3), and (4):

[0024]

[0025] |y0(ω q )| 2 =∑ m |H m (ωq )| 2 (4)

[0026] That is, the final output power at each frequency is the sum of the power of each port at that frequency.

[0027] In one embodiment, in a 5G millimeter-wave communication application, the base station's phase array antenna sequentially changes the beamcode to alter the direction of the array antenna field pattern beam, and repeatedly transmits broadcast signals to a mobile phone equipped with the mobile phone's millimeter-wave antenna system. The mobile phone receives the RSSI (radio signal strength indicator) of the broadcast signals transmitted by different beamcodes and reports to the base station which beamcode is most suitable for the mobile phone. Subsequently, the base station uses that beamcode to conduct data communication with the mobile phone.

[0028] In this embodiment, the mobile phone millimeter-wave antenna system can be applied to an FDD (Frequency Division Duplex) system or a TDD (Time Division Duplex) system.

[0029] In one embodiment, during the uplink data transmission process of the frequency division duplex system, an optimal antenna element is selected from these antenna elements to transmit the uplink data. The optimal antenna element m0 ​​is determined according to formula (5):

[0030] m0 = max{R(i0, m)}; (5)

[0031] Where R(i0, m) is the RSSI of the broadcast signal received by the m-th antenna element out of four antenna elements when a base station transmits with beam code i0.

[0032] To further explain the structure, features, and purpose of the present invention, a detailed description of preferred embodiments is provided below with reference to the accompanying drawings. Attached Figure Description

[0033] Figure 1 A block diagram illustrating an embodiment of the multi-port, multi-antenna element mobile phone millimeter-wave antenna system of the present invention is shown.

[0034] Figures 2a-2e Block diagrams of five existing mobile phone millimeter-wave antenna systems are shown.

[0035] Figure 3 A schematic diagram simulating the human body using a flat plate model is shown.

[0036] Figure 4 A schematic diagram of microstrip antenna configurations placed on different planes of a mobile phone is shown.

[0037] Figure 5 An indoor environment with an antenna architecture is shown.

[0038] Figures 6a-6g The frequency response diagrams for propagation loss during downlink reception are shown for different antenna architectures.

[0039] Figure 7 The distribution of users' locations within a room is shown.

[0040] Figures 8a-8f It shows Figure 7 The cumulative probability distribution (CDF) curve for each location and orientation.

[0041] Figure 8g This illustrates the difference between single-port multi-array architecture and multi-port multi-element architecture. Figure 8e and Figure 8f The comparison curve proposed in the article. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0043] Figure 1 A block diagram illustrating an embodiment of the multi-port, multi-antenna element mobile phone millimeter-wave antenna system of the present invention is shown. Figure 1 As shown, a mobile phone millimeter-wave antenna system 100 has multiple antenna elements 101, multiple mixer units 102, multiple analog-to-digital converter units 103 and a baseband signal processor 104, wherein the baseband signal processor 104 has multiple weighting function modules 104a and a summing function module 104b.

[0044] In the architecture of this invention, each antenna element 101 is considered a port, and the output signal H of each port is... m (ω), where m represents the port position, is processed by a mixer unit 102 and an analog-to-digital converter unit 103 to generate a baseband digital signal H. m (ω q ), each fundamental frequency digital signal H m (ω q Each signal is multiplied by a weighting function W by a corresponding weighting function module 104a within the baseband signal processor 104. m (ω q Then, the summing function module 104b will perform a summing calculation to generate a system output signal H. M (ω q ), H M (ωq )=∑ m W m (ω q )·H m (ω q ).

[0045] Furthermore, in the architecture described above, the output signal H of each port... m (ω) is processed by a T / R (transmit / receive) switch and a low-noise amplifier (not shown in the figure), and the mixer unit 102 and the analog-to-digital converter unit 103 are combined to provide OFDM signal processing to generate the baseband digital signal H. m (ω q That is, the mixer unit 102 uses two local oscillation frequency signals with a phase difference of 90 degrees to respectively mix H. m (ω) is used for mixing, while the analog-to-digital converter unit 103 is used to perform analog-to-digital conversion operations on the two orthogonal signals after mixing to generate the baseband digital signal H. m (ω q H m (ω q ) represents the m-th antenna element at a subcarrier frequency of ω. q The channel response at real time can be measured or estimated from the pilot signal or reference signal channel; that is, the real-time channel response (frequency response) is obtainable.

[0046] Additionally, it is worth noting the various weighting functions W m (ω q The combination of signals at each port is a function of the subcarriers, meaning that the optimal combination of signals at each port depends on the condition of each subcarrier. Each subcarrier has its own weighting function, unlike the beamforming method of an antenna array, where each element is multiplied by the same phase.

[0047] In addition, this invention proposes a rule for selecting base station beamcodes in a multi-port, multi-antenna element architecture, as well as a signal processing rule for uplink and uplink data transmission.

[0048] During 5G millimeter-wave communication, the base station's phase array antenna sequentially changes the beam code to alter the direction of the array antenna beam pattern and repeatedly transmits broadcast signals to the mobile phone. The mobile phone receives the RSSI (radio signal strength indicator) of the broadcast signals transmitted by different beam codes and reports to the base station which beam code is most suitable for the mobile phone. The base station then uses that beam code to conduct data communication with the mobile phone.

[0049] The beam code selection rule of this invention:

[0050] Let R(i, m) be the RSSI of the m-th antenna element among the four antenna elements when the base station transmits with beam code i. Then, the method for determining beam code i0 proposed in this invention is as shown in formula (6):

[0051]

[0052] After the mobile phone reports the beam code i0 to the base station, the base station will use this beam code to transmit uplink and downlink data with the mobile phone.

[0053] Furthermore, this invention proposes a multi-port, multi-antenna element architecture for signal processing rules in downlink and uplink data transmission. For uplink data transmitting, this invention proposes two systems: FDD (Frequency Division Duplex) and TDD (Time Division Duplex). In the FDD system, the carrier frequencies for uplink and downlink transmissions are different, therefore the uplink and downlink channel responses are different. The weighting function for downlink reception cannot be used as the weighting function for uplink transmission. We propose selecting one element as the transmitting antenna for uplink data transmission. This antenna element m0 ​​is determined according to formula (5):

[0054] m0 = max{R(i0, m)}; (5)

[0055] In a TDD system, the uplink and downlink use the same carrier frequency, resulting in identical frequency responses. Therefore, the weighting function obtained for the uplink can be directly applied to the downlink transmission. Each antenna element is multiplied by its weight w. m (ω q After transmission, the uplink receiving performance at the base station can be the same as the downlink receiving performance at the mobile phone. Therefore, in a TDD system, the architecture of this invention will also be superior to the single-port multi-array architecture for the uplink receiving performance of the base station.

[0056] The following is a comparison of the differences between this invention and existing mobile phone millimeter-wave antenna systems:

[0057] Existing mobile phone millimeter-wave antenna architectures include single-port single antenna element architecture, single-port single linear array antenna architecture, single-port multi-antenna element architecture, single-port multi-array antenna architecture, and multi-port multiple linear array architecture.

[0058] 1. For example Figure 2a As shown, the single-port, single-antenna element architecture: the antenna's analog output is denoted as H(ω), and after passing through a mixer and A / D (analog-to-digital converter), the sampled subcarrier output is denoted as H(ω). q ), ω q Let q be the frequency of the q-th subcarrier.

[0059] 2. For example Figure 2b As shown, the single-port linear array architecture has four antenna elements, each connected to an adjustable phase shifter. The output signal of the p-th element is denoted as H. p (ω), the connected phase shifter will produce The output of the four elements after being combined by a phase shifter is denoted as: For linear arrays The phase angle to be found, for a narrow-frequency system, It is the phase angle at which the maximum output can be obtained, that is As for broadband systems, different subcarriers may have different... therefore It is determined by the average power, that is The function of multiplying each antenna element by its phase angle and then summing them is called a beamformer. The output of the beamformer is denoted as H. B (ω), each subcarrier ω after A / D converter q The output is denoted as H. B (ω q ).

[0060] 3. For example Figure 2c As shown, the single-port multi-antenna element architecture: the output of the m-th element is denoted as H. m (ω), this architecture compares the average output power of all elements and selects the element m0 ​​with the maximum average power, that is... As the sole element for future data transmission, the output after A / D conversion is denoted as...

[0061] 4. For example Figure 2d As shown, the single-port multi-antenna array architecture: the output of the m-th array after beamforming is denoted as H. mB(ω), compare the average power output of each array. And select the array with the highest average power, denoted as array m0. The m0 array will serve as the sole array for future data transmission. After passing through the A / D converter, the output of the antenna system is denoted as...

[0062] 5. For example Figure 2e As shown, the multi-port multi-array architecture has M ports and M beamforming arrays. The output of the m-th array after beamforming is denoted as H. mB (ω), H after A / D mB (ω q The signal is fed into the baseband signal processor, and the H signal at each port... mB (ω q Then multiply each by W m (ω q The final total output signal is H. BM (ω q )=∑ m W m (ω q )·H mB (ω q ).

[0063] Different antenna architectures have different levels of complexity and different transmission performance, especially in indoor environments with multipath waves and in the millimeter wave band, where signals have a large bandwidth.

[0064] Reception characteristics of different millimeter-wave antenna architectures in mobile phones

[0065] Ray-tracing is a primary tool for studying the propagation characteristics of radio waves indoors or outdoors. Given the dimensions, layout, material composition, and positions of transmitting and receiving antennas within the room, ray-tracing can track the time delay, angle of departure, angle of arrival, and complex amplitude of multipath waves from the transmitting antenna through walls, ceilings, floors, furniture, and other reflections to the receiving antenna.

[0066] Mobile phone use is frequently associated with the human body, with the most common uses being making phone calls and checking messages. We use a simple tablet model to simulate the human body; the model's dimensions and components are shown below. Figure 3 .

[0067] The focus of this invention is not on the detailed design of the antenna body; here we only consider it as a general microstrip antenna (patch antenna).

[0068] Microstrip antennas can be configured in various ways; for example, they can be a single antenna element, a linear array, or a planar array. They can be placed on different planes of the mobile phone, such as... Figure 4 As shown.

[0069] The following section will use ray tracing software to explore the millimeter-wave channel characteristics of different antenna architectures in an indoor environment.

[0070] Considering interior space, such as Figure 5 As shown, the base station is located at position Tx, with spatial coordinates (x... t y t , z t The phone is located at (x) r y r , z r Several microstrip antenna elements are located on different surfaces of the phone. Patch 1 is located on the top of the narrow edge, Patch 2 and Patch 3 are located on the narrow surfaces on the left and right sides of the phone, respectively, and Patch 4 is located on the circuit board on the back of the screen. These four microstrip antennas have the same dimensions. The parameters of the patch are: length = 0.35cm, width = 0.34cm, thickness = 0.1cm, dielectric constant of the substrate = 2.2. The center position of the phone and the coordinates of the center of each patch relative to the center of the phone are also shown in the figure. The person and the phone are considered as one. When the person faces different directions, the phone also rotates with the person. The software can accurately calculate the center position and radiation pattern of each antenna at any position of the person and in any direction they are facing. We can also calculate the elevation angle and azimuth angle of the line of sight (LOS) connecting the base station antenna and the phone antenna. In the following simulation, we assume that the tilt angle of the phone is 30°.

[0071] Assume the base station antenna is an 8x8 phase array antenna. The array has a fixed field pattern in the vertical direction, with a maximum direction of θ0 = 90°, and its antenna field pattern can be represented by formula (7).

[0072]

[0073] in, The azimuth and angle to be aligned. It is the field pattern of the array antenna elements, if The corresponding field pattern is called the beam number i. The array antenna can use different beam numbers i to communicate with the mobile phone. The mobile phone can select the optimal beam number i and then report it to the base station. The base station then uses this beam number to communicate with the mobile phone for data. The rules for selecting beam numbers for different mobile phone antenna architectures will be briefly described below.

[0074] Beamcode Selection Rules

[0075] In millimeter-wave mobile communication systems, base stations typically use a broadcast channel and sequentially transmit broadcast signals to users using different beamcodes. Users measure the Radio Signal Strength Indicator (RSSI) of the broadcast signal and report back to the base station which beamcode has the strongest RSSI. The base station then uses this beamcode for data communication with the mobile phone. Therefore, the first priority between the mobile phone and the base station is selecting the beamcode of the base station's phase array antenna. The following will present rules for beamcode selection for different antenna architectures.

[0076] Radio wave intensity (RSSI) can be measured instantly. The bandwidth of broadcast signals is much smaller than that of data signals. To simulate the RSSI of broadcast signals, we approximate it using the average channel power response of the channel response within the bandwidth of the broadcast signal. That is, the radio wave intensity can be expressed by formula (8).

[0077]

[0078] Assume that the base station phase array antenna sequentially changes its beamcode, causing the main beam to sequentially change to different directions. Let there be I = 2M possible main beam directions, where M is the number of elements of the antenna in the lateral direction, and the phase angle corresponding to the i-th direction is... for For each aligned phase angle (Steering Phase angle) We can use ray tracing software to obtain the channel response of each antenna element in the mobile phone.

[0079] The beamcode selection rules for different antenna architectures of mobile phones are briefly described below:

[0080] a) Single-port, single-element architecture

[0081] Let the single element be Patch m, where m = 1, 2, 3, 4. When the ith-th beamcode is transmitted, the RSSI measured by Patch m is denoted as R(i, m), and the beamcode to be selected by the mobile phone is denoted as i. 0m i 0m The value is obtained from formula (9).

[0082] i 0m =max i {R(i, m)}, m=1, 2, 3, 4(9).

[0083] b) Single-port single-array architecture

[0084] A single array can be an array of patch m, where m = 1, 2, 3, 4. The frequency response of the p-th element of the m-th array to beamcode i is denoted as H. mp (i, ω), p = 1, 2, 3, 4, the array is beamformed to phase. The output value is represented by formula (10).

[0085]

[0086] Let R m (i, s) represents the value of array m when the beamcode is i and the beam is shaped to the s-th phase angle. (i, s) is defined as... 0m s 0m The value of ) is obtained from formula (11).

[0087] i 0m s 0m =max i，s {R m (i, s)};(11)

[0088] Then i 0m It is the beam code that array m will select, while s 0m The s-th element to be selected for beamforming of array m 0m Phase angle, during uplink data transmission, s 0m It is also the s-th element to be selected for array m. 0m Phase angle.

[0089] c) Single-port multi-element architecture

[0090] Let R(i, m) be the RSSI value measured for patch m with beam code i. This is different from architecture (a). In this case, all four patches are used simultaneously. The beam code i0 and the patch code m0 to be selected are determined by formula (12).

[0091] i0, m0 = max i，m {R(i, m)};(12)

[0092] Then Patch m0 will be the element used for uplink and downlink data communication.

[0093] d) Single-port multi-array architecture

[0094] Each patch array has four elements, let H mp (i, ω) represents the frequency response of the p-th element of the m-th array when the beamcode is i. When the m-th array uses... The output value of beamforming by phase angle is shown in formula (13).

[0095]

[0096] Let R(i, m, s) be the RSSI measured when beamforming is performed with beam code i, m-th array, and s-th phase angle. Then the selected beam code, array code, and phase angle code are determined by formula (14).

[0097] i0, m0, s0 = max i，m，s {R(i, m, s)};(14)

[0098] The m0 array and its corresponding phase code s0 will serve as the array and phase code for uplink and downlink data communication.

[0099] e). The multi-port, multi-element architecture adopted in this invention

[0100] Let H m (i, ω) represents the channel response of the m-th Patch element when the beamcode is i. The selected beamcode is determined by formula (6).

[0101]

[0102] When receiving downlink data, all elements are used for receiving. When transmitting uplink data, in a TDD (Time Division Duplex) system, the uplink and downlink use the same carrier frequency and have the same channel response, so all antenna elements are used for data transmission. However, in an FDD (Frequency Division Duplex) system, the uplink and downlink carrier frequencies are different, so the uplink and downlink channel responses are different. Therefore, only one element can be used for uplink data transmission. Which element transmits the uplink data signal is determined by formula (5).

[0103] m0 = max m {R(i0, m)};(5)

[0104] f) Multi-port multi-array architecture

[0105] Some symbols are defined the same as (d), let s 0im This is expressed by formula (15).

[0106] s 0im =max s {R(i, m, s)};(15)

[0107] Then R(i, m, s) 0im When the beamcode is i, the m-th array is beamformed to the s-th array. 0im The RSSI value at phase angle is expressed by formula (16).

[0108]

[0109] The selected beam code i0 is determined by formula (17).

[0110] i0 = max i {R iT};(17)

[0111] When performing downlink data transmission, S 0im The phase code will be used as the beamforming phase code for the m-th array. All four arrays will be used for receiving. During uplink data transmission, if it is a TDD system, all four arrays will be used as transmitting antennas. If it is an FDD system, only one array will be selected to transmit the data signal. The array code is determined by formula (18).

[0112] m0 = max m {R(i0, m, s) 0im )};(18)

[0113] Once the beam code, element / array code, and phase angle code are determined, the output values ​​for various antenna architectures are calculated as follows:

[0114] a) Single-port, single-element architecture

[0115] Let H m (i, ω) q If ) is the channel response of Patch m with beam code i, then the output value of Patch m is expressed by formula (19).

[0116] y m (ω q )=H m (i0, ω) q (19)

[0117] b) Single-port single-array architecture

[0118] Let H mp (i, ω) q Let ) be the p-th element of array m, and let i be the channel response of beam code i. The output value of array m is expressed by formula (20).

[0119]

[0120] c) Single-port multi-element architecture

[0121] The output value of the system is represented by formula (21).

[0122]

[0123] d) Single-port multi-array architecture

[0124]

[0125] e). The multi-port, multi-element architecture adopted in this invention

[0126] Let w m (ω q ) is the m-th element in ω q When using the MRC (Maximum Ratio Combining) rule to combine weight functions, the weight function w... m (ω q ) is expressed by formula (23).

[0127]

[0128] The output value after MRC is represented by formula (24).

[0129] In a TDD system, uplink and downlink use the same carrier frequency and therefore have the same channel response. During uplink data transmission, all four elements act as transmit antennas, and each element is multiplied by the aforementioned weighting function. The base station antenna's uplink reception also produces the aforementioned output value.

[0130] f) Multi-port multi-array architecture

[0131] The weight function of the m-th array is expressed by formula (25).

[0132]

[0133] in The final total output signal is represented by formula (26).

[0134]

[0135] In a TDD system, during uplink data transmission, all four arrays function as transmit antennas simultaneously, and each array is multiplied by the aforementioned weighting function. The base station's uplink reception response is also as described above.

[0136] Simulation results

[0137] Place the base station antenna at (x) t =10m, y t =1m,z t =2.5m), the center coordinates of the mobile phone are (x r =16m, y r =5m, z r =1.3m), the phone's tilt angle is 30°.

[0138] Table 1 shows the results of using ray tracing software to simulate an indoor base station and mobile phone interaction, utilizing broadcast signals and the measured RSSI of various antenna architectures to select beam codes, element / array codes, and phase codes. There are two possible angles for the human face: facing the base station (LOS is not obstructed by the human) and facing away from the base station (LOS is obstructed by the human). Table 1 shows that when the LOS is not obstructed, the beam codes selected by various antenna architectures are 2 or 3. The directional angles corresponding to these two beam codes are closest to the azimuth angle of the direct wave. When the LOS is obstructed, the beam codes selected for each element and array code are not identical, and the selected beam codes are not exactly the same as those selected when the LOS is not obstructed.

[0139] Table 1

[0140]

[0141]

[0142] Once the beam code is selected, the base station uses that beam to transmit data with the mobile phone. The mobile phone will use the corresponding elements / arrays and phase codes to receive downlink data and transmit uplink data. Figures 6a to 6g These are the frequency responses of propagation loss during downlink reception for different antenna architectures. A closer look at these frequency response diagrams reveals that, at this location, regardless of whether the LOS is blocked, the propagation loss response performance of the array architecture is not necessarily better than that of the element architecture. In some patch types, the element architecture outperforms the array architecture, while in others the array architecture outperforms the element architecture, and in still others, they are roughly equivalent. In other words, in indoor environments, the transmission performance of an array architecture after beamforming is not necessarily better than that of a single element. Beamforming can enhance signals, but it requires a primary incoming wave. When there are many path waves coming from different directions, the effectiveness of beamforming will be significantly reduced.

[0143] On the other hand, it can be observed that multi-port, multi-element / multi-array architectures, when combined with MRC, can effectively improve transmission performance, as they do not require the selection of any particular element or array for reception. According to the principles of MRC, it can be proven that after MRC integration, the total output SNR (signal-to-noise ratio) is the sum of the SNRs of the individual ports.

[0144] To more clearly compare the propagation loss response of the multi-port, multi-element architecture of this invention with that of the existing single-port, multi-array architecture, we start from... Figure 6e and Figure 6f Extract the corresponding curves and plot both together on [the graph]. Figure 6g By comparison, we can better see the superiority of multi-port, multi-element architecture.

[0145] Furthermore, the selection of beamcode, element code / array code, and phase code is based on the measured RSSI. This is because the bandwidth of broadcast signals is much smaller than that of data signals. In indoor environments, multipath waves arriving from different directions and at different times can interfere with each other, sometimes resulting in severe attenuation along the frequency axis. The measured RSSI only represents the radio wave intensity within the broadcast signal bandwidth but cannot reflect the performance of the entire data signal bandwidth. Therefore, the selected beamcode, element code / array code, and phase code may not be the best choice. However, if we use a multi-port architecture combined with MRC, the severe fading caused by multipath waves can be effectively eliminated, resulting in a more stable overall output level.

[0146] Statistical characteristics of the response of different antenna architecture channels throughout the room

[0147] The results shown above were from a specific location and two specific orientations (facing the base station and facing away from the base station). Below, we will present the transmission performance statistics for multiple locations and orientations, and various antenna architectures.

[0148] Users are distributed in the room as follows Figure 7 As shown, there are 16 positions in total, each with six orientations. Let the spherical coordinate of the j-th position relative to the center of the base station be . When users face When the direction is correct, the phone is blocked by a person, and the person is facing... In other words, when facing a BS (Browser Base), the LOS (Location of Shift) is in a clear state. Due to the width of the body and the distance between the phone and the body, when the body faces... Within the range, LOS is blocked by the human body; from other angles, LOS is not blocked. However, the radiation pattern and polarization of each patch element change depending on the angle. At each location, we face six directions: In the first three directions, LOS will be blocked by the human body; in the last three directions, LOS will not be blocked by the human body.

[0149] For each location and each orientation, we followed the steps described above. For each antenna architecture, we first selected the beam code, element code / array code, and phase code, then calculated the propagation loss response at the output of each antenna architecture. We divided the 16 locations and 6 orientations into two categories: LOS-clear and LOS-obstructed, and plotted the Cumulative Density Function (CDF) curves. The results are shown below. Figures 8a to 8fAs shown in the figure, single-port single-element / single-array architecture exhibits a large frequency response variation range. Even with beamcode selection, there is still a chance of propagation loss exceeding 100dB, indicating severe deep fading. Single-port multi-element / multi-array architecture, after selecting the optimal element or array, shows improved performance, but with human obstruction, there is still a chance of propagation loss exceeding 95dB. Conversely, multi-port multi-element / multi-array architecture, after incorporating MRC, significantly reduces the propagation loss variation range, with all losses below 86dB. We will compare the single-port multi-array architecture and the multi-port multi-element architecture from... Figure 8e and Figure 8f The comparison is presented in the table below, and the results are shown in the table below. Figure 8g The results show that the multi-port, multi-element architecture significantly outperforms the single-port, multi-array architecture. (At CDF=10) -2 It improved by 7dB at CDF=10 -3时则提 It increased by 12dB.

[0150] The present invention has the following advantages based on the design described above:

[0151] 1. Each port contains only a single patch element. A single patch element occupies little space and can be placed in a very flexible location. It can be placed on the narrow bezel of the phone or on the back circuit board, unlike an array antenna (which contains four patch elements) which has more limited placement options.

[0152] Second, the antenna elements of this invention do not have phase shifters. Currently, mobile phone millimeter-wave antennas consist of several array antennas, each array composed of four antenna elements, and each antenna element is connected to a phase shifter to change the phase. Phase shifters cause 2-3 dB of insertion loss. Furthermore, several array antennas select an optimal array antenna for both transmission and reception, thus requiring a selection switch. This selection switch causes 1-2 dB of insertion loss, which leads to a decrease in signal level, generates additional heat, and consumes more battery power. The architecture proposed in this invention does not have these concerns.

[0153] Third, this invention is particularly suitable for indoor environments with multipath waves and situations where direct waves are blocked by the human body. When direct waves are blocked by the human body, and the incoming wave to the mobile phone lacks a dominant wave, the beamforming function of the array antenna is difficult to perform, and the interference between multipath waves causes signal attenuation at different frequencies. This invention uses a multi-port combination, where each frequency component of the signal is sampled and fed into the baseband signal processor, where it is effectively combined individually for each frequency. Therefore, attenuation in the frequency direction can be effectively eliminated.

[0154] Fourth, the microstrip antenna element architecture used in this invention is easily integrated with the newly developed Antenna on-chip technology to improve the manufacturing process of mobile phones.

[0155] Fifth, the antenna architecture of the present invention is a multi-port architecture, which, in conjunction with the multi-port antenna architecture of the base station, can transmit up to four sets of independent data simultaneously using MIMO transmission; in contrast, the existing single-port multi-array antenna architecture does not have MIMO functionality.

[0156] The portion described in this specification represents preferred embodiments. Any partial changes or modifications that arise from the technical concept of the invention and are easily deduced by those skilled in the art do not depart from the scope of the patent rights of the invention.

[0157] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A millimeter-wave antenna system for mobile phones, comprising: Multiple antenna elements, each providing one port; Multiple mixing units, each used to perform a mixing process on the output signal of the port; Multiple analog-to-digital converter units are used to perform an analog-to-digital conversion on the output signals of the mixer units to generate multiple baseband digital signals. as well as A baseband signal processor has multiple weighting function modules and a summing function module, wherein the weighting function modules are used to multiply each of the baseband digital signals by a corresponding weighting function, and the summing function module is used to sum the output values ​​of the weighting function modules. The weight function corresponding to the m-th port is expressed as shown in formula (1): （ ）= ；（1） Where m is a positive integer. ( ) represents the weight function, Represents the q-th subcarrier, This represents the m-th antenna element at a subcarrier frequency of Channel response at that time.

2. The mobile phone millimeter-wave antenna system according to claim 1, wherein, This mixing process is an OFDM signal processing.

3. The mobile phone millimeter-wave antenna system according to claim 1, wherein, The antenna element is a microstrip antenna.

4. The mobile phone millimeter-wave antenna system according to claim 1, wherein, The output formulas of the summation function module are shown in formulas (2), (3), and (4): （ ）= （ ）；（2） = = ；（3） = ；（4） That is, the final output power at each frequency is the sum of the power at each port at that frequency, where, ( ) represents the m-th antenna element at a subcarrier frequency of The fundamental frequency digital signal generated at that time ( This indicates that the summing function module operates at a subcarrier frequency of... The output value at that time, and ( ( ) )= , For something unrelated to m but related to the subcarrier frequency Constants related to the information they carry.

5. The mobile phone millimeter-wave antenna system according to claim 1, wherein, In 5G millimeter-wave communication applications, the base station's phase array antenna sequentially changes the beamcode to alter the direction of the array antenna field pattern beam and repeatedly transmits broadcast signals to a mobile phone equipped with the mobile phone's millimeter-wave antenna system. The mobile phone receives the RSSI of the broadcast signals transmitted by different beamcodes and reports to the base station which beamcode is most suitable for the mobile phone. Subsequently, the base station uses that beamcode to conduct data communication with the mobile phone.

6. The mobile phone millimeter-wave antenna system according to claim 1 is applied to a frequency division duplex system or a time division duplex system.

7. The mobile phone millimeter-wave antenna system according to claim 6, wherein, During the uplink data transmission process of this frequency division duplex system, an optimal antenna element is selected from these antenna elements to transmit the uplink data. Determined according to formula (5): =max{R( , m)};(5) Among them, R ( (m) is a base station beamcode During transmission, the m-th antenna element out of the four antenna elements receives the RSSI of the broadcast signal.

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