Method for antenna selection of user equipment

Abstract

The invention provides a method for antenna selectin of a user equipment (UE). The UE may comprise a plurality of antennas. The method may comprise calculating one or more quality evaluations respectively associated with one or more first antenna subsets, and selecting one of the one or more first antenna subsets according to the one or more quality evaluations. Each antenna subset may include one or more of the plurality of antennas. Each quality evaluation may be calculated under a condition that the antenna(s) included in the associated antenna subset is (are) used to communicate.

Description

[Technical Field]

[0001] The present invention relates generally to an antenna selection method for user equipment (UE), and in particular to a method for selecting fewer antennas from all antennas in an antenna set for wireless communication in a hierarchical and self-adjusting manner, thereby effectively reducing the power consumption of wireless communication without affecting the communication quality. [Previous Technology]

[0002] Modern user equipment (UE) includes multiple antennas for wireless communication, and how to use antennas effectively and intelligently is the key to the development of UE technology. [Summary of the Invention]

[0003] One object of the present invention is to provide an antenna selection method for a UE (e.g., UE 10 in Figure 1 or 2) (e.g., 400 or 600 in Figure 4 or 6). The UE may include a plurality of antennas for wireless communication (e.g., a[1] to a

[12] in Figure 1, or a[1] to a[N] in Figure 2). The method may be performed by the UE (e.g., a processor or UE) and may include: performing a quality assessment step (e.g., 407 in Figures 4 and 5a to 5c, or 607 in Figures 6 and 7a to 7c), and performing a preliminary selection step (e.g., 409 in Figures 4, 5a to 5c, or 609 in Figures 6, 7a to 7c). The quality assessment step may include: calculating one or more quality assessments (e.g., Q[i,j] in Figure 4 or 6, or Q[2,1] to Q[2,2] in Figure 5a or 7a) respectively associated with one or more first antenna subsets (e.g., S[i,j] in Figure 2, 4, or 6, or S[2,1] to S[2,2] in Figure 1, 5a, or 7a). The preliminary selection step may include: selecting one or more first antenna subsets based on one or more quality assessments. Each of the one or more first antenna subsets may include one or more of a plurality of antennas. Each of one or more quality assessments associated with one of one or more first antenna subsets (e.g., S[2,1] or S[2,2] in 5a or 7a of Figure 1) (e.g., Q[2,1] or Q[2,2] in Figure 5a or 7a) may include one or more communication qualities and may be calculated if one or more of the antennas included in the associated first antenna subset (e.g., a[1] to a[4] or a[5] to a[6] in Figure 1, 5a or 7a) are used for communication (e.g., transmission and / or reception).

[0004] In one embodiment (e.g., Figure 4 or 6), the method may further include (e.g., step 401 in Figure 4 or 6): prior to the quality assessment step (e.g., 407 or 607 in Figure 4 or 6), calculating a plurality of channel estimates (e.g., ch[1] to ch[N] in Figure 4 or 6) respectively associated with a plurality of antennas. When one or more quality assessments are calculated in the quality assessment step, the UE may calculate one or more quality assessments based on the plurality of channel estimates.

[0005] In one embodiment (e.g., Figure 4 or Figure 6), the method may further include performing a weight construction step (e.g., Figure 405 or Figure 6) prior to the quality assessment step (e.g., 407 or 607 in Figure 4 or Figure 6). The weight construction step may include constructing one or more weight vectors of the current level (e.g., txV[i,j] in Figure 4, rxV[i,j] in Figure 6, txV[2,1] to txV[2,2] in Figure 5a or Figure 7a) respectively associated with one or more subsets of first antennas (e.g., S[i,j] in Figure 4, or rxV[2,1] to rxV[2,2] in Figure 5a, or rxV[2,1] to rxV[2,2] in Figure 7a). Each of one or more current-level weight vectors associated with one or more first antenna subsets (e.g., S[2,1] or S[2,2] in Figure 5a or 7a) (e.g., txV[2,1] or txV[2,2] in Figure 5a, or rxV[2,1] or rxV[2,2] in Figure 7a) may include one or more current-level weights associated with one or more antennas included in the associated first antenna subset (e.g., a[1] to a[4] or a[5] to a[6] in Figure 5a or 7a) (e.g., txw[2,1,1] to txw[2,1,4] or txw[2,2,5] to txw[2,2,8] in Figure 5a, or rxw[2,1,1] to rxw[2,1,4] in Figure 7a). Or rxw[2,2,5] to rxw[2,2,8]).Each of one or more quality assessments (e.g., Q[2,1] or Q[2,2] in Figure 5a or 7a) is associated with one of one or more first antenna subsets (e.g., S[2,1] or S[2,2] in Figure 5a or 7a), and is calculated as follows: one or more antennas contained in the associated first antenna subset (e.g., a[1] to a[4] or a[5] and a[6] in Figure 5a, or a[1] and a[2] or a[3] and a[4] in Figure 7b) are used for communication, wherein one or more current level weights (e.g., txw[2,1,1] in Figure 5a) are included in the associated current level weight vector (e.g., txV[2,1] or txV[2,2] in Figure 5a, or rxV[2,1] or rxV[2,2] in Figure 7a). The above one or more antennas are weighted together (from txw[2,1,4] or txw[2,2,5] to txw[2,2,8], or rxw[2,1,1] to rxw[2,1,4] or rxw[2,2,5] to rxw[2,2,8] in Figure 7a).

[0006] In one embodiment (e.g., Figure 8a), when constructing a particular current level weight vector (e.g., txV[2,1] in Figure 5a) among one or more current level weight vectors (wherein the particular current level weight vector is associated with a particular first antenna subset (e.g., S[2,1] in Figure 5a) among one or more first antenna subsets), the UE may obtain one or more previous weights (e.g., txw0[1] to txw0[4] in Figure 5a), and may set one or more current level weights (e.g., txw[2,1,1] to txw[2,1,4] in Figure 5a) included in the particular current level weight vector based on one or more previous weights. One or more prior weights (e.g., txw0[1] to txw0[4] in Figure 5a) may be associated with one or more of the antennas included in a particular first antenna subset (e.g., S[2,1]) (e.g., a[1] to a[4] in Figure 5a) and may be recorded prior to the weight construction step (e.g., 405 in Figure 5a).

[0007] In one embodiment (e.g., Figure 8b), when constructing a particular current level weight vector (e.g., txV[2,1] in Figure 5a) among one or more current level weight vectors (wherein the particular current level weight vector is associated with a particular first antenna subset (e.g., S[2,1] in Figure 5a) among one or more first antenna subsets), the UE may compute one or more current level weights (e.g., txw[2,1,1] to txw[2,1,4] in the particular current level weight vector by solving a beamforming optimization problem, in the case of (e.g., only) using one or more of the antennas included in the particular first antenna subset (e.g., a[1] to a[4] in Figures 1, 5a and 8b).

[0008] In one embodiment (e.g., Figure 4 or Figures 5c to 5e), the method may further include performing a high-level selection step (e.g., 413 in Figures 4, 5d, or 5e, or 613 in Figure 6 or 7c) after performing a preliminary selection step (e.g., 409). The high-level selection step may include selecting one of one or more second-day line subsets from a candidate pool (e.g., txCP or rxCP in Figure 4 or 6) comprising one or more second-day line subsets (e.g., S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] in Figure 4 or 6) based on one or more parameter evaluations (e.g., P[i1,j_selected_at_i1] to P[iZ,j_selected_at_iZ]). One or more parameter evaluations may be associated with one or more subsets of second antennas, and each of the one or more subsets of second antennas may include one or more of the plurality of antennas. The preliminary selection step may also include: after selecting one of the one or more subsets of first antennas based on one or more quality evaluations, including the selected one of the one or more subsets of first antennas (e.g., S[i,j_selected_at_i]) in the candidate pool.

[0009] In one embodiment (e.g., Figure 4 or 6), the method may further include: prior to the advanced selection step, calculating one or more parameter evaluations associated with one or more subsets of second antennas respectively (e.g., P[i,j] in Figure 4 or 6). Each of the one or more parameter evaluations may be associated with one or more subsets of second antennas and may include one or more parameters of the UE, and may be calculated in the case of (e.g., only) one or more antennas used for communication included in the associated second antenna subsets.

[0010] In one embodiment (e.g., Figure 4 or 6), selecting one or more subsets of second antennas based on one or more parameter evaluations may include: selecting one or more compatible antenna subsets (e.g., S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G]) from one or more subsets of second antennas as one or more compatible antenna subsets based on one or more counts associated with one or more compatible antenna subsets respectively; and selecting one of the one or more compatible antenna subsets (e.g., S[ig,j_selected_at_ig] in Figure 4 or 6) as one of the selected one or more subsets of second antennas based on one or more counts associated with one or more compatible antenna subsets respectively. Each of one or more counts may be associated with one of one or more compatible antenna subsets, and may involve counts of one or more antennas included in one of the associated compatible antenna subsets.

[0011] In one embodiment, one or more operational requirements may involve one or more of the following: maximum power reduction (MPR), power management maximum power reduction (P-MPR), error vector magnitude (EVM), and time-averaged power density.

[0012] In one embodiment, when selecting one or more compatible antenna subsets based on one or more counts associated with one or more compatible antenna subsets respectively, the compatible antenna subset associated with the lowest count is selected from the one or more compatible antenna subsets.

[0013] In one embodiment, the method may further include: after selecting one of one or more compatible antenna subsets, causing the UE to use one or more antennas included in the selected antenna subset of one or more compatible antenna subsets for subsequent communication.

[0014] In one embodiment, when the UE uses one or more antennas in a selected antenna subset included in one or more compatible antenna subsets for subsequent communication, the UE is further made not to use the remaining antennas in the plurality of antennas.

[0015] In one embodiment, each of one or more parameter evaluations may be associated with one or more subsets of second antennas and may involve the power of one or more power amplifiers of one or more antennas included in the associated antenna subsets of one or more second antennas.

[0016] In one embodiment (e.g., Figure 4 or 5e), each of one or more antenna subsets may be a strict subset of a previous antenna subset.

[0017] In one embodiment, the method may further include: after selecting one of one or more antenna subsets based on one or more quality assessments, repeatedly performing the quality assessment step and the primary selection step by: calculating one or more next-level quality assessments associated with one or more next-level antenna subsets, and selecting one or more next-level antenna subsets based on one or more next-level quality assessments. Each of the one or more next-level antenna subsets may include one or more of a plurality of antennas. Each of the one or more next-level quality assessments may be associated with one or more next-level antenna subsets and may be calculated in cases where (e.g., only) one or more antennas included in the associated next-level antenna subsets are used for communication. The count of one or more antennas included in each of the one or more next-level antenna subsets may not be greater than the count of one or more antennas included in the selected one of the one or more first antenna subsets.

[0018] In one embodiment, at least one of the one or more next-level antenna subsets may be a strict subset of one or more of the selected one of the first antenna subsets.

[0019] In one embodiment (e.g., Figure 6), the method may further include (e.g., step 621): monitoring one or more reception qualities, and may further include: determining whether to repeat the quality assessment step and the preliminary selection step based on one or more reception qualities before repeating the quality assessment step and the preliminary selection step.

[0020] In one embodiment (e.g., Figure 6), the method may further include (e.g., step 621): monitoring one or more reception qualities, and may further include: determining whether to perform the quality assessment step and the preliminary selection step based on one or more reception qualities before performing the quality assessment step and the preliminary selection step.

[0021] In one embodiment (e.g., Figure 6), one or more reception qualities may involve one or more of the following: channel quality, reception quality, throughput, runtime power consumption, whether the downlink data transmission type is dense or sparse, and the type of the current user application.

[0022] In one embodiment, each of one or more quality assessments may include one or more communication qualities that may be associated with one or more of the following: Reference Received Power (RSRP), Reference Received Quality (RSRQ), Received Signal Strength Index (RSSI), and Signal Interference-Noise Ratio (SINR), etc.

[0023] In one embodiment (e.g., Figure 1), two (e.g., S[3,1] and S[3,2]) in one or more antenna subsets are mutually exclusive.

[0024] The object of the present invention is to provide a UE (e.g., UE 10 in Figure 1) that can implement the above-described method. Another object of the present invention is to provide a processor (e.g., processor 130 in Figure 1) that can control the UE to implement the method.

[0025] Many objects, features, and advantages of the present invention will become apparent after reading the following detailed description of embodiments of the invention in conjunction with the accompanying drawings. However, the drawings used herein are for illustrative purposes and should not be considered as limiting.

Implementation Method

[0027] The following description is of the preferred embodiment for carrying out the present invention, and is for the purpose of describing the principles of the invention, not for limiting the invention. The scope of protection of the present invention should be defined by the scope of the claims of the present invention.

[0028] Figure 1 schematically illustrates UE 10 according to an embodiment of the present invention. For example, UE 10 may be a mobile phone, smartphone, tablet computer, notebook computer, laptop computer, desktop computer, wearable device (e.g., smartwatch, headphones or glasses, etc.), drone, digital camera, digital camcorder, set-top box, smart speaker, game console, home appliance (e.g., smart TV, air conditioner, lighting system, refrigerator, washing machine, etc.), office equipment (e.g., photocopier, printer, audio or video conferencing system, monitoring system, etc.), Internet of Things (IoT) device, router, remote information processing system, navigator, or any electronic device that implements wireless communication (e.g., mobile communication) functionality.

[0029] UE 10 may include an antenna group (e.g., an antenna array) 100, a radio frequency (RF) circuit group 110, an RF module 120, and a processor 130. The antenna group 100 may include one or more antennas, such as antennas a[1] to a

[12] in the example of Figure 1. The radio frequency (RF) circuit group 110 may include one or more radio frequency (RF) circuits, such as RF circuits rfc[1] to rfc

[16] in the example of Figure 1. Each RF circuit rfc[k] (index k = 1 to 16 in the example of Figure 1) may be coupled between the associated antenna a[n] (index n is one of 1 to 12 in the example of Figure 1) and the RF module 120, and may cooperate with antenna a[n]. Each antenna a[n] (in the example of Figure 1, index n equals 1 to 12) can be coupled to one or more associated RF circuits and thus cooperate with one or more associated RF circuits; as shown in the example of Figure 1, antenna a[1] can be coupled to and cooperate with a single RF circuit rfc[1], while antenna a[5] can be coupled to and cooperate with two RF circuits rfc[5] and rfc[6].

[0030] The radio frequency module 120 can be coupled between the processor 130 and the radio frequency circuit group 110, and can convert between the analog radio frequency signal of the radio frequency circuit group 110 and the digital baseband signal of the processor 130. The processor 130 can be formed by digital logic circuitry; the processor 130 works in conjunction with the antenna group 100, the radio frequency circuit group 110 and the radio frequency module 120, and can guide the operation of the UE 10. For example, the processor 130 can control the UE 10 to communicate wirelessly with remote participants (not depicted) of the wireless network (such as base stations of mobile telecommunications networks). The UE 10 may also include other circuitry and / or hardware modules, such as a graphics processing unit, a signal processing unit, power management circuitry, one or more memory modules, and / or human-machine interface modules, such as a display panel, a touch sensing module, a keyboard, buttons, a speaker, a microphone, sensors and / or a camera, etc.

[0031] As shown in Figure 1, to implement the present invention, the antenna group 100 can be divided into one or more levels of antenna subsets, wherein different levels can correspond to different levels of detail in the division. For example, as shown in Figure 1, the antenna subset S[0,1] can be the 0th level subset of the antenna group 100, which can include all antennas a[1] to a

[12] of the antenna group 100. The antenna group 100 can be divided into two first-level antenna subsets S[1,1] and S[1,2], which can respectively include antennas a[1] to a[6] and a[7] to a

[12] of the antenna group 100. The antenna group 100 can also be divided into four second-level antenna subsets S[2,1] to S[2,4], which can respectively include antennas a[1] to a[4], a[5] to a[6], a[7] to a

[10] and a

[11] to a

[12] . Antenna group 100 can be further divided into six third-level antenna subsets S[3,1] to S[3,6], which can respectively contain antennas a[1] to a[2], a[3] to a[4], a[5] to a[6], a[7] to a[8], a[9] to a

[10] and a

[11] to a

[12] . Antenna group 100 can also be divided into twelve fourth-level antenna subsets S[4,1] to S[4,12], which can respectively contain antennas a[1] to a

[12] .

[0032] Figure 2 depicts a general arrangement of antenna subsets at different levels. As shown in Figure 2, antenna group 100 may include antennas a[1] to a[N], where N is a predetermined integer. Antennas a[1] to a[N] may be included in the zero-level antenna subset S[0,1] and may be grouped into J[i] i-level antenna subsets S[i,1] to S[i,J[i]], where for indices i = 1 to I, number I is a predefined integer and number J[i] is an integer that may vary with the index i (in the example in Figure 1, j[1] = 2, j[2] = 4, j[3] = 6 and J[4] = 12). Each antenna subset S[i,j] may include one or more of antennas a[1] to a[N]. In one embodiment, each antenna subset S[i,j] may not include all antennas a[1] to a[N]. As shown in Figure 2, the antenna group 100 can be divided into J[1] first-level antenna subsets S[1,1] to S[1,J[1]], J[2] second-level antenna subsets S[2,1] to S[2,J[2]]...J[I] first-level antenna subsets S[I,1] to S[I,J[I]. In one embodiment, the number J[i] can be less than or equal to the number J[i+1]. In one embodiment, the number of antennas contained in the (i+1)th-level antenna subset S[i+1,j'] (called the number of antennas in the antenna subset S[i+1,j']) can be less than or equal to the number of antennas contained in the i-th-level antenna subset S[i,j] (i.e., the number of antennas in the antenna subset S[i,j]), where the index j' is one of 1 to J[i+1], and the index j is one of 1 to J[i]. In one embodiment, the quantity J[I] can be equal to the quantity N, and each I-th level antenna subset S[I,j] can include a single antenna a[j] from antenna a[1] to a[N].

[0033] In one embodiment, the (i+1)th level antenna subset S[i+1,j2] may be a strict subset of the i-th antenna subset S[i,j1], where index j2 is one of 1 to J[i+1] and index j1 is one of 1 to J[i]. For example, any antenna included in the antenna subset S[i+1,j2] may also be included in the antenna subset S[i,j1], and the subset S[i,j1] may also include one or more other antennas that are not included in the antenna subset S[i+1,j2]. In one embodiment, the (i+1)th level antenna subset S[i+1,j4] may be equal to the i-th antenna subset S[i,j3], where index j3 is one of 1 to J[i] and index j4 is one of 1 to J[i+1].

[0034] In one embodiment, the i-th level antenna subset S[i,j5] can be the union of two or more of the (i+1)-th level antenna subsets S[i+1,1] to S[i+1,J[i+1]], for example, antenna subsets S[i+1,j6] and S[i+1,j7], where index j5 is one of 1 to J[i], and indices j6 and j7 are two different ones from 1 to J[i+1]. In one embodiment, the i-th level antenna subset S[i,j8], where index j8 is one of 1 to J[i], may not be the union of any two (or more) of the (i+1)-th level antenna subsets S[i+1,1] to S[i+1,J[i+1]].

[0035] In one embodiment, two i-th level antenna subsets S[i,j9] and S[i,j10] can be mutually exclusive; for example, antenna a[n1] contained in antenna subset S[i,j9] may not be contained in antenna subset S[i,j10], and antenna a[n2] contained in antenna subset S[i,j10] may not be contained in antenna subset S[i,j9], where indices j9 and j10 are two different numbers from 1 to J[i], and indices n1 and n2 are two different numbers from 1 to N. In one embodiment, two i-th level antenna subsets S[i,j11] and S[i,j12] may be different but have a non-empty intersection; for example, antenna subset S[i,j11] may include antennas a[n3] and a[n4], while antenna subset S[i,j12] may include antennas a[n3] and a[n5], where indices j11 and j12 are two different numbers from 1 to J[i], and indices n3, n4 and n5 are three different numbers from 1 to N.

[0036] The example in Figure 1 seems to suggest that antennas a[1] to a

[12] are grouped sequentially into antenna subsets S[i,1] to S[i,J[i]]. For example, the first four antennas a[1] to a[4] are grouped into the first antenna subset S[2,1] to S[2,4], the next two antennas a[5] and a[6] are grouped into the second antenna subset S[2,1] to S[2,4], and the subsequent four antennas a[7] to a

[10] are grouped into the third antenna subset S[2,1] to S[2,4], and so on. However, the invention is not limited thereto. In different examples (not depicted), the antenna subset S[2,1] may include antennas a[1], a[3] and a[5], and the antenna subset S[2,2] may include antennas a[2], a[4] and a[6], etc.; in another example, the antenna subset S[2,1] may include antennas a[1], a[3], a[8] and a

[10] , and the antenna subset S[2,3] may include antennas a[2], a[4], a[7] and a[9], etc.

[0037] Although the antennas a[1] to a

[12] or a[1] to a[N] in the antenna group 100 shown in Figure 1 or Figure 2 respectively seem to suggest that the antennas of the antenna group 100 are geometrically arranged in a one-dimensional linear array, the present invention is not limited thereto. The antennas of the antenna group 100 may be geometrically distributed on a plane, a curved surface (e.g., a cylinder), or a complex surface including one or more curved portions and / or one or more parallel or non-parallel planar portions. For example, regarding antennas a[1] to a

[12] in Figure 1, antennas a[1] to a[2] and a[7] to a[8] can form a linear array on the left side surface (not depicted) of UE 10, antennas a[5], a[6], a

[11] and a

[12] can form a linear array on the back side of UE 10, and antennas a[3] to a[4] and a[9] to a

[10] can form another linear array on the right side surface of UE 10; as a different example, antennas a[1] to a[4] and a[7] to a

[10] can form a rectangular array on the top side surface of UE 10, and antennas a[5] to a[6] and a

[11] to a

[12] can form a linear array on the bottom side of UE 10.

[0038] The antenna of the antenna group 100 can be implemented by one or more radiating structures. In one embodiment, two or more antennas can be implemented by the same radiating structure. For example, regarding antennas a[1] to a

[12] shown in Figure 1, antennas a[1] and a[7] can be implemented by two different types (modes) of resonance of the same radiating structure, for example, by vertical polarization resonance and horizontal polarization resonance of patch radiation, respectively; and / or, antennas a[5] and a

[11] can be implemented by vertical polarization resonance and horizontal polarization resonance of dipole radiation structure, respectively.

[0039] As shown in Figure 2, the radio frequency circuit group 110 may include radio frequency circuits rfc[1] to rfc[K] to cooperate with antennas a[1] to a[N] of the antenna group 110, wherein the number K is a preset integer. Each RF circuit rfc[k] may be coupled to an associated antenna a[n] of the antenna group 100, with indices k = 1 to K and index n being one of 1 to N, and thus may cooperate with antenna a[n]. In one embodiment, the number K may be greater than or equal to the number N, and each antenna in the antenna group 100 may be coupled to and cooperate with one or more radio frequency circuits in the radio frequency circuit group 110.

[0040] Figure 3 schematically depicts the radio frequency circuit rfc[k] of the radio frequency circuit group 110 coupled between the associated antenna a[n] and the radio frequency module 120 of the antenna group 100. The radio frequency circuit rfc[k] can cooperate with the associated antenna a[n] and can include a power amplifier PA[k], a low noise amplifier LNA[k], and a weighting circuit ps[k]. The weighting circuit ps[k] and the power amplifier PA[k] can respectively weight (through weight txW[k]) and amplify the outgoing radio frequency signal so[k] to form the transmitted radio frequency signal st[k], and the antenna a[n] can transmit the transmitted RF signal st[k] by transmitting electromagnetic waves. Antenna a[n] can also receive incoming electromagnetic waves to form a received radio frequency signal sr[k]. Therefore, the low-noise amplifier LNA[k] and weighting circuit ps[k] can amplify and weight (through weight rxW[k]) the received radio frequency signal sr[k] respectively to form an incoming radio frequency signal si[k]. When weighting signals so[k] and sr[k], the weighting circuit ps[k] can adjust the amplitude and / or phase of signals so[k] and sr[k] according to the weights txW[k] and rxW[k]. In addition to amplifier PA[k], LNA[k], and weighting circuit ps[k], the RF circuit rfc[k] may also include one or more other circuits not shown in Figure 3 for simplicity.

[0041] When antenna a[n] is used for communication (e.g., transmitting and / or receiving), the associated cooperating RF circuitry (i.e., the RF circuitry coupled to antenna a[n]) will be enabled for use and will consume power. When antenna a[n] is not used for communication, the associated RF circuitry will be disabled and will not consume power.

[0042] Figure 4 depicts a flowchart 400 according to an embodiment of the present invention. Processor 130 (Figure 1 or 2) can control UE 10 to select an antenna for wireless transmission using flowchart 400. Flowchart 400 may include steps 401, 403, 405, 407, 409, 411, and 413, and steps 405, 407, and 409 may be referred to as the preliminary transmit antenna selection process 480, which may be repeated once or multiple times for hierarchical selection. The steps of flowchart 400 can be described as follows.

[0043] Step 401: The processor 130 can control the UE 10 to perform a beamforming process. For example, the processor 130 can control the UE 10 to perform a beamforming process with a remote participant (e.g., a base station) of the wireless network, for example, by sending a wireless outgoing reference signal to the remote participant and receiving a wireless response signal from the remote participant, and receiving an incoming reference signal from the remote participant and measuring the received incoming reference signal.

[0044] The beamforming process can generate a transmission weight vector txV0 and a reception weight vector rxV0. The weight vector txV0 can include the transmission weights txw0[1] to txw0[K] for the RF circuits rfc[1] to rfc[K] (Figure 2) of the RF circuit group 110, respectively. When the UE 10 transmits using all the antennas a[1] to a[N] (and all the RF circuits rfc[1] to rfc[K]) in the antenna group 100, the UE 10 can use the transmission weights txw0[1] to txw0[K] as the weights txW[1] to txW[K] of the RF circuits rfc[1] to rfc[K] (Figures 2 and 3) to optimize the wireless transmission. The weight vector rxV0 may include the reception weights rxw0[1] to rxw0[K] for the RF circuits rfc[1] to rfc[K] (Figure 2) of the RF circuit group 110, respectively. When the UE 10 uses all the antennas a[1] to a[N] (and all the RF circuits rfc[1] to rfc[K]) in the antenna group 100 for reception, the UE 10 may use the reception weights rxw0[1] to rxw0[K] as the weights rxW[1] to rxW[K] for the RF circuits rfc[1] to rfc[K] (Figures 2 and 3) to optimize wireless reception.

[0045] However, it should be noted that the weights txw0[1] to txw0[K] and rxw0[1] to rxw0[K] of the weight vectors txV0 and rxV0 are derived and calculated under the condition that all antennas a[1] to a[N] and all RF circuits rfc[1] to rfc[K] are used for communication by UE 10. Communication using all antennas a[1] to a[N] and all RF circuits rfc[1] to rfc[K] is very power-intensive. The processor 130 of UE 10 can systematically select using flowchart 400, and use fewer antennas and fewer RF circuits when UE 10 transmits, and thus reduce power consumption (and gain other additional advantages) without compromising the quality of wireless communication.

[0046] Based on the results of the beamforming process, the processor 130 of the UE 10 can further calculate (solve) and / or obtain the channel estimates ch[1] to ch[N] for antennas a[1] to a[N]. Each channel estimate ch[n] (for indices n = 1 to N) can indicate the channel response when only antenna a[n] is used for communication, for example, it can indicate how the timing, phase and / or amplitude of the RF signal is as the RF signal propagates between antenna a[n] and the remote participant.

[0047] Step 403: The processor 130 may initialize the level index i, the parent set txS, and the candidate pool txCP. For example, suppose the processor 130 aims to systematically select fewer antennas for transmission from the i0th level antenna subset S[i0,j0], where the indices i0 and j0 are one of 1 to N and one of 1 to J[i0] respectively (as shown in Figure 2), and the antenna subset S[i0,j0] includes one or more antennas cooperating with one or more RF circuits rfc[k_1] to rfc[k_U], where if U>1, the indices k_1 to k_U are distinct numbers from 1 to K. Then the processor 130 may set the level index i to be greater than the index i0 (e.g., equal to (i0+1)), set the parent set txS to be equal to the antenna subset S[i0,j0], and set the candidate pool txCP to an empty set.

[0048] Step 405: For each i-th level antenna subset S[i,j] that is a subset of the parent set txS, the processor 130 of the UE 10 can construct a weight vector txV[i,j] as the current level weight vector associated with the antenna subset S[i,j]. Step 405 can be called the weighted construction step.

[0049] For example, suppose that the parent set txS includes one or more i-th level antenna subsets S[i,j_1] to S[i,j_D] (if D>1, for indices j_1 to j_D are different indices from 1 to J[i]) as its subsets, then the processor 130 can construct one or more weight vectors txV[i,j_1] to txV[i,j_D] respectively associated with one or more antenna subsets S[i,j_1] to S[i,j_D]. Since each antenna subset S[i,j_d] (where index j_d is each from j_1 to j_D) can include one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M] (where if H > 1, indices n_1 to n_H are distinct indices from 1 to N, and if M > 1, indices k_1 to k_M are distinct indices from 1 to K), each weight vector txV[i,j_d] associated with the antenna subset S[i,j_d] can include one or more weights txw[i,j_d,k_1]. txw[i,j_d,k_M], respectively, are used for RF circuits rfc[k_1] to rfc[k_M] that cooperate with one or more antennas a[n_1] to a[n_H] contained in the antenna subset S[i,j_d].

[0050] Figure 8a depicts an embodiment of the weight construction in step 405. To construct a weight vector txV[i,j_d] associated with an antenna subset S[i,j_d] comprising one or more antennas a[n_1] to a[n_H], wherein one or more antennas a[n_1] to a[n_H] cooperate with one or more RF circuits rfc[k_1] to rfc[k_M], the processor 130 of UE 10 can obtain one or more previous weights from the weights txw0[1] to txw0[K] of the weight vector txV0, for example, one or more weights txw0[k_1]. The weight vector txV[i,j_d] can be set to include one or more weights txw[i,j_d,k_1] to txw[i,j_d,k_M] based on one or more previous weights txw0[k_1] to txw0[k_M]. For example, the processor 130 can set one or more weights txw[i,j_d,k_1] to txw[i,j_d,k_M] to be substantially equal to one or more previous weights txw0[k_1] to txw0[k_M].

[0051] When constructing one or more weights txw[i,j_d,k_1] to txw[i,j_d,k_M] of a weight vector txV[i,j_d] based on one or more previous weights, one or more previous weights can also be one or more weights txw[i',j',k_1] to txw[i',j',k_M], including the weight vector txV[i',j'] constructed in step 405 of the previous iterative operation. In the figure (if it exists), index i' is one of 1 to I (Figure 2) and is not equal to (e.g., less than) the current level index i, index j' is one of 1 to J[i'] (Figure 2), and the weight vector txV[i',j'] is associated with the antenna subset S[i',j'] as a subset of the antenna subset S[i0,j0] (step 403), and may include the antenna subset S[i,j_d]. One or more previous weights txw0[k_1] to txw0[k_M] or txw[i',j',k_1] to txw[i',j',k_M] can be associated with one or more RF circuits rfc[k_1] to rfc[k_M], wherein one or more RF circuits cooperate with one or more antennas a[n_1] to a[n_H] included in the associated antenna subset S[i,j_d], and are acquired and recorded prior to the weight construction step 405 of the current iterative operation (e.g., in step 401 or step 405 of the previous iterative operation).

[0052] Figure 8b depicts another embodiment of the weight construction in step 405. In order to construct a weight vector txV[i,j_d] associated with the antenna subset S[i,j_d] (including one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M]), when the UE 10 communicates using only one or more antennas a[n_1] to a[n_H] (Figure 2) and cooperating with one or more RF circuits rfc[k_1] to rfc[k_M], and without using the remaining antennas of antenna group 100 and the remaining RF circuits of RF circuit group 110, the processor 130 of the UE 10 can calculate txw[i,j_d,k_1] to txw[i,j_d,k_M] included in the weight vector txV[i,j_d] by solving the beamforming optimization problem.

[0053] Step 407 (Figure 4): For each i-th level antenna subset S[i,j] that is a subset of the parent set txS, the processor 130 of UE 10 can calculate the quality assessment Q[i,j] associated with the antenna subset S[i,j]. Step 407 can be referred to as the quality assessment step. The quality assessment Q[i,j] can include one or more communication qualities and can be calculated under the condition that UE 10 communicates using only the antennas and cooperating RF included in the antenna subset S[i,j] and without using the antennas and cooperating RF circuits not included in the antenna subset S[i,j]. In one embodiment, one or more communication qualities in each quality evaluation Q[i,j] associated with the antenna subset S[i,j] may involve one or more of the following: Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indicator (RSSI), and Signal Interference-Noise Ratio (SINR), as well as other qualities that may reflect the channel quality and / or communication quality between the antennas of the antenna subset S[i,j] and the remote participant.

[0054] Furthermore, for each i-th level antenna subset S[i,j] that is a subset of the parent set txS, the processor 130 of UE 10 can also compute a parameter evaluation P[i,j] associated with the antenna subset S[i,j]. When UE 10 uses only the antennas included in the antenna subset S[i,j] for communication (e.g., transmission) and does not use the antennas not included in the antenna subset S[i,j], the parameter evaluation P[i,j] can quantitatively reflect one or more instruction arguments of UE 10.

[0055] Since the parent set txS (step 405) can include one or more i-th level antenna subsets S[i,j_1] to S[i,j_D] as its subsets, the processor 130 of UE 10 can calculate one or more quality evaluations Q[i,j_1] to Q[i,j_D] associated with one or more antenna subsets S[i,j_1] to S[i,j_D] respectively, and one or more parameter evaluations P[i,j_1] to P[i,j_D] associated with one or more antenna subsets S[i,j_1] to S[i,j_D] respectively. In the case where UE 10 uses only one or more antennas a[n_1] to a[n_H] and cooperating RF circuits rfc[k_1] to rfc[k_M] and communicates (e.g., transmits) without using the remaining antennas of antenna group 100 and the remaining RF circuits of RF circuit group 110 (where they are weighted by one or more weights txw[i,j_d,k_1] to txw[i,j_d,k_M] included in the weight vector txV[i,j_d] associated with the antenna subset S[i,j_d] (step 405)), based on the channel estimates ch[1] to ch[N] associated with antennas a[1] to a[N] of antenna group 100 (step 401), processor 130 of UE 10 can calculate quality assessment Q[i,j_d] (index j_d is each of j_1 to j_D), where quality assessment Q [i,j_d] is associated with an antenna subset S[i,j_d], which includes one or more antennas a[n_1] to a[n_H] that cooperate with one or more RF circuits rfc[k_1] to rfc[k_M].In other words, when UE 10 uses only one or more antennas a[n_1] to a[n_H] and one or more radio frequency circuits rfc[k_1] to rfc[k_M] for communication, and the remaining antennas of antenna group 100 and the remaining radio frequency circuits of radio frequency circuit group 110 are not used, wherein one or more radio frequency circuits rfc[k_1] to rfc[k_M] respectively adopt one or more weights txw[i,j_d,k_1] to txw[i,j_d,k_M] contained in the constructed weight vector txV[i,j_d] (step 405) as one or more weights txW[k_1] to txW[k_M] of one or more radio frequency circuits rfc[k_1] to rfc[k_M] (Figure 2 or 3), UE The processor 130 of 10 can calculate a quality assessment Q[i,j_d], wherein the quality assessment Q[i,j_d] is associated with an antenna subset S[i,j_d] comprising one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M].

[0056] Similarly, when UE 10 uses only one or more antennas a[n_1] to a[n_H] and one or more radio frequency circuits rfc[k_1] to rfc[k_M] for communication, and the remaining antennas of antenna group 100 and the remaining RF circuits of RF circuit group 110 are not used, wherein one or more weights txw[i,j_d,k_1] to txw[i,j_d] of the construction weight vector txV[i,j_d] associated with the antenna subset S[i,j_d] are respectively weighted by one or more radio frequency circuits rfc[k_1] to rfc[k_M], UE The processor 130 of the 10 can compute each parameter evaluation P[i,j_d], which is associated with an antenna subset S[i,j_d] comprising one or more antennas a[n_1] to a[n_H] that cooperate with one or more radio frequency circuits rfc[k_1] to rfc[k_M].

[0057] In one embodiment, the parameter evaluation P[i,j_d] associated with an antenna subset S[i,j_d] including one or more antennas a[n_1] to a[n_H] cooperating with RF circuits rfc[k_1] to rfc[k_M] may include information reflecting the compensation power value deltaP[i,j_d] associated with the antenna subset S[i,j_d]. The compensation power value deltaP[i,j_d] can be calculated by subtracting the subset antenna power value RSRP[i,j_d] from all antenna power values ​​RSRP0. The subset antenna power value RSRP[i,j_d] can reflect the reference signal received power (RSRP) when the UE 10 communicates using only one or more antennas a[n_1] to a[n_H] and one or more cooperating radio frequency circuits rfc[k_1] to rfc[k_M], where, in this case, one or more radio frequency circuits rfc[k_1] to rfc[k_M] are respectively weighted by one or more weights txw[k_1] to txw[k_M] in the construction weight vector txV[i,j_d] associated with the antenna subset S[i,j_d]. When UE 10 communicates using all antennas a[1] to a[N] and all cooperating RF circuits rfc[1] to rfc[K] (where the RF circuits rfc[1] to rfc[K] are weighted by the weights txw0[1] to txw0[K] of the weight vector txV0 respectively (step 401)), the power value RSRP0 of all antennas can reflect the RSRP of the above situation.

[0058] When UE 10 uses only one or more antennas a[n_1] to a[n_H] in the antenna subset S[i,j_d] and one or more cooperating RF circuits rfc[k_1] to rfc[k_M] for communication, UE 10 can increase the power of one or more power amplifiers PA[k_1] to PA[k_M] (Figure 3) in one or more RF circuits rfc[k_1] to rfc[k_M] according to the compensation power value deltaP[i,j_d]. Therefore, the signal output power of one or more RF circuits rfc[k_1] to rfc[k_M] can reach the predetermined target power.

[0059] Step 409: Based on the quality evaluation associated with the antenna subsets in the parent set txS, the processor 130 can select one of the antenna subsets included in the parent set txS, update the parent set txS to the selected antenna subset, and include the selected antenna subset in the candidate pool txCP. Then, the processor 130 can proceed to step 411. Step 409 can be referred to as the preliminary selection step. Since the parent set txS can include one or more antenna subsets S[i,j_1] to S[i,j_D], the processor 130 can select one or more antenna subsets S[i,j_1] to S[i,j_D] based on the quality evaluations Q[i,j_1] to Q[i,j_D] associated with the antenna subsets S[i,j_1] to S[i,j_D] respectively. For example, if the quality evaluation Q[i,j_selected_at_i] associated with the antenna subset S[i,j_selected_at_i] is the best among the quality evaluations Q[i,j_1] to Q[i,j_D], then the processor 130 can select the antenna subset S[i,j_selected_at_i] from one or more antenna subsets S[i,j_1] to S[i,j_D] (where the index j_selected_at_i is one of j_1 to j_D). Next, the processor 130 updates the parent set txS to the selected antenna subset S[i,j_selected_at_i], and can include the selected antenna subset S[i,j_selected_at_i] in the candidate pool txCP, for example, by appending the antenna subset S[i,j_selected_at_i] to the candidate pool txCP.

[0060] Step 411: Processor 130 may determine whether to run another iteration of the preliminary transmit antenna selection process 480 to further check whether fewer antennas and cooperating RF circuits can be selected from the parent set txS updated in step 409. If processor 130 determines to run another iteration, processor 130 may iterate back to step 405, where the level index i is updated to another value, e.g., an increased value. On the other hand, if processor 130 determines not to run another iteration, the processor may proceed to step 413. Processor 130 may determine whether to run another iteration of steps 405, 407, and 409 based on one or more considerations, e.g., whether index i is below a predefined iteration threshold value, and / or whether the quality evaluation Q[i,j_selected_at_i] associated with the selected antenna subset S[i,j_selected_at_i] in step 409 is still within a predefined acceptable quality range (e.g., better than a predefined quality threshold value), etc.

[0061] Step 413: After one or more repeated operations in the preliminary selection process of transmitting antenna 480, the candidate pool txCP may include one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] (if Z>1, the indices i1 to iZ are different values ​​from 1 to 1), wherein the above antenna subsets are generated by one or more repeated operations in step 409. One or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] are respectively associated with one or more parameter evaluations P[i1,j_selected_at_i1] to P[iZ,j_selected_at_iZ] calculated in one or more repeated operations in step 407. The processor 130 can evaluate whether P[i1,j_selected_at_i1] to P[iZ, j_selected_at_iZ] meets one or more transmission operation requirements based on one or more parameter evaluations. And based on the number of antennas (and / or the number of RF circuits) of each of the one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ], one of the one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] is selected.

[0062] For example, in one embodiment, the processor 130 may select one or more compatible antenna subsets S[#1,j_selected_at_i1] to S[#G,j_selected_at_#G] from one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] contained in the candidate pool txCP, wherein if G > 1, then the indices #1 to #G are distinct values ​​in i1 to iZ. For each antenna subset S[iz,j_selected_at_iz] (where index iz is each from i1 to iZ) included in the candidate pool txCP, processor 130 selects antenna subset S[iz,j_selected_at_iz] as a compatible antenna subset if the correlation parameter evaluation P[iz,j_selected_at_iz] satisfies the transmission operation requirements, and may not select antenna subset S[iz,j_selected_at_iz] as a compatible antenna subset if the correlation parameter evaluation P[iz,j_selected_at_iz] does not satisfy the transmission operation requirements. Then, processor 130 can select the antenna subset with the lowest number of antennas (and / or RFs) from one or more compatible antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G]. For example, if the number of antennas (and / or the number of RF circuits) of the antenna subset S[ig,j_selected_at_ig] is the lowest among one or more antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G], then the processor 130 can select the antenna subset S[ig,j_selected_at_ig] from one or more compatible antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G] (where the index ig is one of #1 to #G).After selecting an antenna subset S[ig,j_selected_at_ig], the processor 130 can control the UE 10 to use the antennas included in the selected antenna subset S[ig,j_selected_at_ig] and the RF circuitry cooperating with the antennas included in the antenna subset S[ig,j_selected_at_ig] for subsequent wireless communication (e.g., transmission), wherein the weighted antennas in the weighted antenna subset S[ig,j_selected_at_ig] are included in the associated weight vector txV[ig,j_selected_at_ig]; and control the UE 10 not to use the remaining antennas (i.e., antennas other than those included in the selected antenna subset S[ig,j_selected_at_ig]) and the RF circuitry cooperating with the remaining antennas.

[0063] In one embodiment, the transmission operation requirements may include power requirements associated with one or more of the following: maximum power reduction (MPR), power management maximum power reduction (P-MPR), error vector magnitude (EVM), and time average power density (TA-PD). As previously described, when describing step 407, the parameter evaluation P[i,j_d] associated with the antenna subset S[i,j_d] may include information reflecting the compensation power value deltaP[i,j_d] associated with the antenna subset S[i,j_d], and the compensation power value deltaP[i,j_d] may be related to the power of the power amplifiers PA[k_1] to PA[k_M] of the RF circuits rfc[k_1] to rfc[k_M] that cooperate with antennas a[n_1] to a[n_H] in the associated antenna subset S[i,j_d]. Therefore, when processor 130 checks whether parameter evaluation P[iz,j_selected_at_iz] meets the transmission operation requirements in step 413, processor 130 can check whether the compensation power value deltaP[iz,j_selected_at_iz] meets the power requirements. The power of power amplifiers PA[k_1] to PA[k_M] should be kept within an acceptable power range (e.g., below a power threshold value); if the power of power amplifiers PA[k_1] to PA[k_M] exceeds the acceptable power range (e.g., above a power threshold value), the performance of power amplifiers PA[k_1] to PA[k_M] and the RF transmission performance of UE 10 will be reduced, for example, suffering from higher nonlinearity, higher radiation, and / or higher communication errors. Since power requirements may be related to the acceptable power range, the processor 130 can check whether the power of the power amplifiers PA[k_1] to PA[k_M] is within the acceptable power range by checking whether the compensation power value deltaP[iz,j_selected_at_iz] of the embedded parameter evaluation P[iz,j_selected_at_iz] meets the power requirements included in the transmission operation requirements.

[0064] In flowchart 400, since the selected antenna subset S[ig,j_selected_at_ig] that is checked in step 413 to meet the transmission operation requirements is only a subset of the parent set txS in step 403, the ability to reduce the number of antennas (and RF circuits) used for transmission can be indicated from step 403 to step 413.

[0065] It is worth noting that there are various embodiments to represent the flowchart 400 in Figure 4, and the above representation of flowchart 400 may only be one embodiment. Flowchart 400 may have more or fewer steps.

[0066] Figures 5a to 5e depict an example of applying flowchart 400 from Figure 4 to UE 10 from Figure 1. As shown in Figure 5a, in step 401, processor 130 (Figure 1) can obtain the transmission weight vector txV0 and the channel estimates ch[1] to ch

[12] associated with antennas a[1] to a

[12] (Figure 1). The weight vector txV0 may include weights txw0[1] to txw0

[16] associated with the RF circuits rfc[1] to rfc

[16] (Figure 1) cooperating with antennas a[1] to a

[12] , and can be calculated if all antennas a[1] to a

[12] and all RF circuits rfc[1] to rfc

[16] are used for communication.

[0067] In step 403, the processor 130 can set the level index i to 2, set the parent set txS to the first-level antenna subset S[1,1] including antennas a[1] to a[6] that cooperate with the radio frequency circuits rfc[1] to rfc[8] (Figure 1), and set the candidate pool txCP to an empty set. By setting the parent set txS to the antenna subset S[1,1], the processor 130 can select between the second-level antenna subsets S[2,1] and S[2,2] through the first iterative operation of the transmit antenna preliminary selection process 480, which are subsets of the antenna subset S[1,1].

[0068] In step 405, the processor 130 may construct weight vectors txV[2,1] and txV[2,2] associated with antenna subsets S[2,1] and S[2,2], respectively. The weight vector txV[2,1] associated with antenna subset S[2,1] (which may include antennas a[1] to a[4] cooperating with RF circuits rfc[1] to rfc[4]) may include weights txw[2,1,1] to txw[2,1,4] associated with RF circuits rfc[1] to rfc[4], respectively. The weight vector txV[2,2] associated with the antenna subset S[2,2] (which may include antennas a[5] to a[6] that cooperate with RF circuits rfc[5] to rfc[8]) may include weights txw[2,2,5] to txw[2,2,8] associated with RF circuits rfc[5] to rfc[8] respectively.

[0069] Referring to Figures 8a and 8b, there are various embodiments for constructing weight vectors txV[2,1] and txV[2,2] in step 405 (Figure 5a). According to Figure 8a, in the embodiment for constructing weight vectors txV[2,1] and txV[2,2], the processor 130 can obtain the weights txw0[1] to txw0[4] and txw0[5] to txw0[8] obtained in step 401, and can set the weight vectors txV[2,1] and txw0[5] according to the weights txw0[1] to txw0[4] and txw0[5] to txw0[8] respectively. The values ​​of the weights txw[2,1,1] to txw[2,1,4] and the values ​​of the weights txw[2,2,5] to txw[2,2,8] of the weight vector txV[2,2] can be set to be approximately equal to the values ​​of the weights txw0[1] to txw0[4] and txw0[5] to txw0[8].

[0070] According to Figure 8b, in the embodiment of constructing weight vectors txV[2,1] and txV[2,2], when the UE 10 only uses antennas a[1] to a[4] (and cooperating RF circuits rfc[1] to rfc[4]) and does not need to use the remaining antennas a[5] to a

[12] and the remaining RF circuits rfc[5] to rfc

[16] for communication, the processor 130 can calculate the weights txw[2,1,1] to txw[2,1,4] of the weight vector txV[2,1] by solving the beamforming problem. Similarly, when UE 10 communicates using only antennas a[5] to a[6] (and cooperating radio frequency circuits rfc[5] to rfc[8]) without using the remaining antennas a[1] to a[4], a[7] to a

[12] and the remaining radio frequency circuits rfc[1] to rfc[4] and rfc[9] to rfc

[16] , processor 130 can calculate the weights txw[2,2,5] to txw[2,2,8] of weight vector txV[2,2] by solving the beamforming problem.

[0071] In another embodiment of constructing weight vectors txV[2,1] and txV[2,2], according to Figure 8a, processor 130 can set the weights txw[2,1,1] to txw[2,1,4] of weight vector txV[2,1], and can calculate the weights txw[2,2,5] to txw[2,2,8] of weight vector txV[2,2] according to Figure 8b. Alternatively, processor 130 can calculate the weights txw[2,1,1] to txw[2,1,4] of weight vector txV[2,1] according to Figure 8b, and can set the weights txw[2,2,5] to txw[2,2,8] of weight vector txV[2,2] according to Figure 8a.

[0072] In step 407 (Figure 5a), the processor 130 can calculate the quality evaluations Q[2,1] and Q[2,2] and the parameter evaluations P[2,1] and P[2,2] associated with the antenna subsets S[2,1] and S[2,2], respectively. In the case where UE 10 communicates using only antennas a[1] to a[4] and cooperating RF circuits rfc[1] to rfc[4] and not the remaining antennas a[5] to a

[12] and the remaining RF circuits rfc[5] to rfc

[16] (weighted by weights txw[2,1,1] to txw[2,1,4] and RF circuits rfc[1] to rfc[4]), calculate the quality assessment Q[2,1] and parameter assessment P[2,1] associated with the antenna subset S[2,1] (which may include antennas a[1] to a[4] cooperating with RF circuits rfc[1] to rfc[4)). In the case where UE 10 communicates using only antennas a[5] to a[6] and cooperating RF circuits rfc[5] to rfc[8] and not the remaining antennas a[1] to a[4], a[7] to a

[12] and the remaining RF circuits rfc[1] to rfc[4] and rfc[9] to rfc

[16] (weighted by weight txw[2,2,5] to txw[2,2,8] weighted RF circuits rfc[5] to rfc[8]), calculate the quality assessment Q[2,2] and parameter assessment P[2,2] associated with the antenna subset S[2,2] (which may include antennas a[5] to a[6] cooperating with RF circuits rfc[5] to rfc[8).

[0073] In step 409, assuming that the quality evaluation Q[2,1] is better than the quality evaluation Q[2,2], the processor 130 can select the antenna subset S[2,1], update the parent set txS to the selected antenna subset S[2,1], and include the antenna subset S[2,1] in the candidate pool txCP, for example, by attaching the antenna subset S[2,1] to the candidate pool txCP. Then, the processor 130 can proceed to step 411.

[0074] In step 411, processor 130 may determine whether to repeat the operation back to step 405. For the sake of discussion, assume that processor 130 decides to return to step 405 for a second repetition, where level index i is updated to three.

[0075] As shown in Figure 5b, in step 405 of the second iteration, since step 409 of the first iteration (Figure 5a) has been updated to include two antenna subsets S[3,1] and S[3,2] as the parent set txS of the antenna subset S[2,1] is updated to include two antenna subsets S[3,1] and S[3,2], the processor 130 can construct weight vectors txV[3,1] and txV[3,2] associated with the antenna subsets S[3,1] and S[3,2], respectively. The weight vector txV[3,1] associated with the antenna subset S[3,1] (which includes antennas a[1] to a[2] that cooperate with RF circuits rfc[1] to rfc[2]) may include weights txw[3,1,1] and txw[3,1,2]. The weight vector txV[3,2] associated with the antenna subset S[3,2] (which includes antennas a[3] to a[4] that cooperate with RF circuits rfc[3] to rfc[4]) may include weights txw[3,2,3] and txw[3,2,4].

[0076] Similar to step 405 of the first repeated operation (Figure 5a), in the embodiment according to Figure 8a, in step 405 of the second repeated operation (Figure 5b), the processor 130 can obtain the previous weights txw0[1] to txw0[4] obtained in step 401, and can set the weights txw[3,1,1], txw[3,1,2], txw[3,2,3] and txw[3,2,4] respectively based on (or substantially equal to) the previous weights txw0[1] to txw0[4]. In different embodiments, processor 130 may set weights txw[3,1,1], txw[3,1,2], txw[3,2,3] and txw[3,2,4] respectively, based on (or substantially equal to) the previous weights txw[2,1,1] to txw[2,1,4] constructed in step 405 of the first iterative operation (Figure 5a). In another embodiment, processor 130 may set weights txw[3,1,1], txw[3,1,2], txw[3,2,3] and txw[3,2,4] based on (or substantially equal to) a combination (e.g., a linear combination) of previous weights txw[2,1,1] to txw[2,1,4] and txw0[1] to txw0[4]. For example, processor 130 may set weight txw[3,1,1] to be equal to a linear combination (weighted sum) of previous weights txw0[1] and txw[2,1,1], etc.

[0077] In the embodiment according to Figure 8b, in step 405 of the second iteration (Figure 5b), when the UE 10 communicates using only antennas a[1] to a[2] (and the cooperating RF circuits rfc[1] to rfc[2]) without using the remaining antennas a[3] to a

[12] and the remaining RF circuits rfc[3] to rfc

[16] , the processor 130 can calculate the weights txw[3,1,1] to txw[3,1,2] of the weight vector txV[3,1] by solving the beamforming problem. Similarly, when UE 10 communicates using only antennas a[3] to a[4] (and cooperating radio frequency circuits rfc[3] to rfc[4]), without using the remaining antennas a[1] to a[2], a[5] to a

[12] and the remaining radio frequency circuits rfc[1] to rfc[2], rfc[5] to rfc

[16] , processor 130 can calculate the weights txw[3,2,3] to txw[3,2,4] of the weight vector txV[3,2] by solving the beamforming problem.

[0078] In step 407 of the second repeated operation (Figure 5b), the processor 130 can calculate the quality evaluations Q[3,1] and Q[3,2] associated with the antenna subsets S[3,1] and S[3,2], as well as the parameter evaluations P[3,1] and P[3,2]. In the case where UE 10 communicates using only antennas a[1] and a[2] and cooperative RF circuits rfc[1] and rfc[2] (where the cooperative RF circuits rfc[1] and rfc[2] are weighted by weights txw[3,1,1] and txw[3,1,2]), without using the remaining antennas a[3] to a

[12] and the remaining RF circuits rfc[3] to rfc

[16] , processor 130 can calculate the quality assessment Q[3,1] and parameter assessment P[3,1] associated with the antenna subset S[3,1] including antennas a[1] and a[2]. Similarly, when UE 10 communicates using only antennas a[3] and a[4] and cooperating RF circuits rfc[3] and rfc[4] without using the remaining antennas a[1] to a[2], a[5] to a

[12] and the remaining RF circuits rfc[1] to rfc[2] and rfc[5] to rfc

[16] (weighted by weights txw[3,2,3] and txw[3,2,4]), processor 130 can calculate the quality assessment Q[3,2] and parameter assessment P[3,2] associated with the antenna subset S[3,2] including antennas a[3] and a[4] cooperating with the associated RF circuits rfc[3] and rfc[4].

[0079] In step 409 of the second iterative operation (Figure 5b), assuming that the quality evaluation Q[3,2] is better than the quality evaluation Q[3,1], the processor 130 can select the antenna subset S[3,2], update the parent set txS to the selected antenna subset S[3,2], and include the antenna subset S[3,2] in the candidate pool txCP. The candidate pool txCP can then include the two antenna subsets S[2,1] and S[3,2] selected in the two iterative operations of step 409, respectively.

[0080] In step 411 of the second iteration (Figure 5b), the processor 130 can determine whether to repeat the iteration back to step 405 to begin another iteration. For ease of discussion, assume that the processor 130 decides to perform a third iteration on step 405, so the processor 130 can proceed to step 405, where the level index i is updated to four.

[0081] As shown in Figure 5c, in step 405 of the third iterative operation, since the target set txS updated to the antenna subset S[3,2] includes antenna subsets S[4,3] and S[4,4] (Figure 1), the processor 130 can construct weight vectors txV[4,3] and txV[4,4] associated with the antenna subsets S[4,3] and S[4,4], respectively. The weight vector txV[4,3] associated with the antenna subset S[4,3] including antenna a[3] cooperating with RF circuit rfc[3] may include weighted txw[4,3,3]. The weight vector txV[4,4] associated with the antenna subset S[4,4] including antenna a[4] cooperating with RF circuit rfc[4] may include weighted txw[4,4,4].

[0082] Similar to step 405 of the previous iterative operation shown in Figures 5a and 5b, in the embodiment of Figure 8a, in step 405 of the third iterative operation (Figure 5c), the processor 130 can obtain the previous weights txw0[3] and txw0[4] obtained in step 401, and can set the weights txw[4,3,3] and txw[4,4,4] respectively based on (or substantially equal to) the previous weights txw0[3] and txw0[4]. In different embodiments, the processor 130 can set txw[4,3,3] and txw[4,4,4] respectively based on (or substantially equal to) the previous weights txw[3,2,3] and txw[3,2,4] included in the weight vector txV[3,2] constructed in step 405 of the second iterative operation (Figure 5b). In another embodiment, the processor 130 may set the weights txw[4,3,3] and txw[4,4,4] respectively based on (or substantially equal to) the previous weights txw[2,1,3] and txw[2,1,4] in the weight vector txV[2,1] constructed in step 405 of the first iterative operation (Figure 5a). In another embodiment, processor 130 may set weights txw[4,3,3] and txw[4,4,4] respectively based on (or substantially equal to) combinations (e.g., linear combinations) of previous weights txw[2,1,3] and txw[2,1,4], txw[3,2,3] and txw[3,2,4], and txw0[3] and txw0[4]; for example, processor 130 may set weight txw[4,3,3] to be equal to a linear combination (weighted sum) of previous weights txw0[3], txw[2,1,3] and txw[3,2,3], etc.

[0083] In the embodiment according to Figure 8b, in step 405 of the third repeated operation (Figure 5c), when the UE 10 uses only antenna a[3] (and the corresponding radio frequency circuit rfc[3]) for communication without using the other antennas a[1] to a[2], a[4] to a

[12] and the other radio frequency circuits rfc[1] to rfc[2], rfc[4] to rfc

[16] , the processor 130 can calculate the weight txw[4,3,3] of the weight vector txV[4,3] by solving the beamforming problem; similarly, when the UE 10 uses only antenna a[4] (and the corresponding radio frequency circuit rfc[4]) for communication without using the other antennas a[1] to a[3], a[5] to a

[12] and the other radio frequency circuits rfc[1] to rfc[3], In the case of RFC[5] to RFC

[16] , the processor 130 can calculate the weights txw[4,4,4] of the weight vector txV[4,4] by solving the beamforming problem.

[0084] In step 407 of the third iterative operation (Figure 5c), the processor 130 can calculate the quality assessments Q[4,3] and Q[4,4] associated with the antenna subsets S[4,3] and S[4,4], as well as the parameter assessments P[4,3] and P[4,4]. When the UE 10 communicates using only antenna a[3] and the cooperating RF circuit rfc[3] (weighted by weight txw[4,3,3]) without using the remaining antennas a[1] to a[2], a[4] to a

[12] and the remaining RF circuits rfc[1] to rfc[2] and rfc[4] to rfc

[16] , the processor 130 can calculate the quality assessment Q[4,3] and parameter assessment P[4,3] associated with the antenna subset S[4,3], which includes antenna a[3] cooperating with the associated RF circuit rfc[3]. Similarly, when UE 10 communicates using only antenna a[4] and the cooperating RF circuit rfc[4] (weighted by weight txw[4,4,4]) without using the remaining antennas a[1] to a[3], a[5] to a

[12] and the remaining RF circuits rfc[1] to rfc[3] and rfc[5] to rfc

[16] , processor 130 can calculate the quality assessment Q[4,4] and parameter assessment P[4,4] associated with the antenna subset S[4,4], which includes antenna a[4] cooperating with the associated RF circuit rfc[4].

[0085] In step 409 of the third repeated operation, assuming that the quality evaluation Q[4,3] is better than the quality evaluation Q[4,4], the processor 130 can select the antenna subset S[4,3], update the parent set txS to the selected antenna subset S[4,3], include the selected antenna subset S[4,3] in the candidate pool txCP, and proceed to step 411. After step 409, the candidate pool txCP may include the antenna subsets S[2,1], S[3,2] and S[4,3] selected in the three repeated operations of step 409.

[0086] In step 411, the processor 130 may determine whether to repeat the operation back to step 405 to begin another repetitive operation. Since level index i=4 has reached the highest level of all antenna subsets from level 0 antenna subset S[0,1] to level 4 antenna subsets S[4,1] to S[4,12] (Figure 1), the processor 130 may decide not to repeat step 405 and may proceed to step 413.

[0087] For the sake of discussion, in the first example of step 413 depicted in Figure 5d, it is assumed that the parameter evaluation of each of the antenna subsets S[2,1], S[3,2] and S[4,3] included in the candidate pool txCP satisfies the transmission operation requirements. Since the number of antennas in the antenna subset S[4,3] (equal to 1) is lower than the number of antennas in the antenna subsets S[2,1] and S[3,2] (equal to 4 and 2 respectively), the processor 130 can select the antenna subset S[4,3] from the antenna subsets S[2,1], S[3,2] and S[4,3]. Then, the processor 130 can enable the UE 10 to use antenna a[3] included in the antenna subset S[4,3], and the cooperative RF circuit rfc[3] weighted by the weight txw[4,3,3] included in the weight vector txV[4,3] for subsequent wireless communication (such as transmission); the UE 10 does not use the remaining antennas a[1] to a[2], a[4] to a

[12] and the remaining RF circuit rfc[1] to rfc[2], rfc[4] to rfc

[16] , and thus the UE 10 can reduce power consumption.

[0088] On the other hand, in the second example of step 413 depicted in Figure 5e, it is assumed that parameter evaluation P[4,3] does not meet the transmission operation requirements, while parameter evaluations P[2,1] and P[3,2] are checked to meet the transmission operation requirements. Since the number of antennas in antenna subset S[3,2] is lower than the number of antennas in antenna subset S[2,1], the processor 130 can select antenna subset S[3,2] from compatible antenna subsets S[3,2] and S[2,1]. Then the processor 130 can enable the UE 10 to use antennas a[3] and a[4] included in the antenna subset S[3,2], and cooperative RF circuits rfc[3] and rfc[4] weighted by weights txw[3,2,3] and txw[3,2,4] included in the weight vector txV[3,2] for subsequent wireless communication (e.g., transmission); the UE 10 does not use the remaining antennas a[1] to a[2], a[5] to a

[12] and the remaining RF circuits rfc[1] to rfc[2], rfc[5] to rfc

[16] , so the UE 10 can reduce power consumption.

[0089] Figure 6 depicts a flowchart 600 according to an embodiment of the present invention. Processor 130 (Figure 1) can control UE 10 to select an antenna for wireless reception using the method of flowchart 600. Flowchart 600 may include steps 401, 603, 605, 607, 609, 611, and 613, wherein steps 605, 607, and 609 may be referred to as a preliminary antenna selection process 680, which may be repeated once or multiple times for hierarchical selection. The steps of flowchart 600 can be described as follows.

[0090] Step 603: After step 401 described with reference to Figure 4, processor 130 may initialize the level index i, the parent set rxS, and the candidate pool rxCP. For example, suppose processor 130 aims to systematically select fewer antennas for reception from the i0th level antenna subset S[i0,j0], where indices i0 and j0 are one of 1 to N and one of 1 to J[i0] respectively (as shown in Figure 2), and the antenna subset S[i0,j0] includes one or more antennas cooperating with one or more RF circuits rfc[ki_1] to rfc[ki_U], where if U > 1, indices ki_1 to ki_U are distinct numbers from 1 to K. Then processor 130 may set the level index i to be greater than the index i0 (e.g., equal to (i0+1)), set the parent set rxS to be equal to the antenna subset S[i0,j0], and set the candidate pool rxCP to an empty set.

[0091] Step 605: For each i-th level antenna subset S[i,j] that is a subset of the parent set rxS, the processor 130 of UE 10 can construct a weight vector txV[i,j] as the current level weight vector associated with the antenna subset S[i,j]. Step 605 can be called the weighted construction step.

[0092] For example, suppose that the parent set rxS includes one or more i-th level antenna subsets S[i,j_1] to S[i,j_D] (if D>1, for indices j_1 to j_D are different indices from 1 to J[i]) as its subsets, then the processor 130 can construct one or more weight vectors rxV[i,j_1] to rxV[i,j_D] respectively associated with one or more antenna subsets S[i,j_1] to S[i,j_D]. Since each antenna subset S[i,j_d] (where index j_d is each from j_1 to j_D) can include one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M] (where if H > 1, indices n_1 to n_H are distinct indices from 1 to N, and if M > 1, indices k_1 to k_M are distinct indices from 1 to K), each weight vector rxV[i,j_d] associated with the antenna subset S[i,j_d] can include one or more weights rxw[i,j_d,k_1]. rxw[i,j_d,k_M], respectively, are used for RF circuits rfc[k_1] to rfc[k_M] that cooperate with one or more antennas a[n_1] to a[n_H] contained in the antenna subset S[i,j_d].

[0093] Figure 9a depicts an embodiment of the weight construction in step 605. To construct a weight vector txV[i,j_d] associated with an antenna subset S[i,j_d] comprising one or more antennas a[n_1] to a[n_H], wherein one or more antennas a[n_1] to a[n_H] cooperate with one or more RF circuits rfc[k_1] to rfc[k_M], the processor 130 of UE 10 can obtain one or more previous weights from the weights rxw0[1] to rxw0[K] of the weight vector rxV0, for example, one or more weights rxw0[k_1]. The weight vector rxV[i,j_d] can be set to include one or more weights rxw[i,j_d,k_1] to rxw[i,j_d,k_M] based on one or more previous weights rxw0[k_1] to rxw0[k_M]. For example, the processor 130 can set one or more weights rxw[i,j_d,k_1] to rxw[i,j_d,k_M] to be substantially equal to one or more previous weights rxw0[k_1] to rxw0[k_M].

[0094] When constructing one or more weights rxw[i,j_d,k_1] to rxw[i,j_d,k_M] of a weight vector rxV[i,j_d] based on one or more previous weights, one or more previous weights can also be one or more weights rxw[i',j',k_1] to rxw[i',j',k_M], including the weight vector rxV[i',j'] constructed in step 605 of the previous iterative operation. In the figure (if present), index i' is one of 1 to I (Figure 2) and is not equal to (e.g., less than) the current level index i, index j' is one of 1 to J[i'] (Figure 2), and the weight vector rxV[i',j'] is associated with the antenna subset S[i',j'] which is a subset of the antenna subset S[i0,j0] (step 603), and may include the antenna subset S[i,j_d]. One or more previous weights rxw0[k_1] to rxw0[k_M] or rxw[i',j',k_1] to rxw[i',j',k_M] can be associated with one or more RF circuits rfc[k_1] to rfc[k_M], respectively, wherein one or more RF circuits cooperate with one or more antennas a[n_1] to a[n_H] included in the associated antenna subset S[i,j_d], and are acquired and recorded prior to the weight construction step 605 of the current iterative operation (e.g., in step 401 or step 605 of the previous iterative operation).

[0095] Figure 9b depicts another embodiment of the weight construction in step 605. In order to construct a weight vector rxV[i,j_d] associated with the antenna subset S[i,j_d] (including one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M]), when the UE 10 communicates using only one or more antennas a[n_1] to a[n_H] (Figure 2) and cooperating with one or more RF circuits rfc[k_1] to rfc[k_M], and without using the remaining antennas of antenna group 100 and the remaining RF circuits of RF circuit group 110, the processor 130 of the UE 10 can calculate rxw[i,j_d,k_1] to rxw[i,j_d,k_M] included in the weight vector rxV[i,j_d].

[0096] Step 607 (Figure 6): For each i-th level antenna subset S[i,j] that is a subset of the parent set rxS, the processor 130 of UE 10 can calculate the quality assessment Q[i,j] and parameter assessment P[i,j] associated with the antenna subset S[i,j]. Step 607 can be referred to as the quality assessment step. The quality assessment Q[i,j] may include one or more communication qualities and can be calculated under the condition that UE 10 communicates using only the antennas and cooperating RF included in the antenna subset S[i,j] and without using the antennas and cooperating RF circuits not included in the antenna subset S[i,j]. In one embodiment, one or more communication qualities in each quality evaluation Q[i,j] associated with antenna subset S[i,j] may involve one or more of the following: Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Received Signal Strength Indicator (RSSI), and Signal-to-Interference-Noise Ratio (SINR), as well as other qualities that may reflect the channel quality and / or communication quality between the antennas in antenna subset S[i,j] and the remote participant. When UE 10 communicates (e.g., receives) using only the antennas included in antenna subset S[i,j] and does not use antennas not included in antenna subset S[i,j], parameter evaluation P[i,j] may quantitatively reflect one or more command arguments of UE 10.

[0097] Since the parent set rxS (step 605) can include one or more i-th level antenna subsets S[i,j_1] to S[i,j_D] as its subsets, the processor 130 of UE 10 can calculate one or more quality evaluations Q[i,j_1] to Q[i,j_D] associated with one or more antenna subsets S[i,j_1] to S[i,j_D] respectively, and one or more parameter evaluations P[i,j_1] to P[i,j_D] associated with one or more antenna subsets S[i,j_1] to S[i,j_D] respectively. In the case where UE 10 uses only one or more antennas a[n_1] to a[n_H] and cooperating RF circuits rfc[k_1] to rfc[k_M] and communicates (e.g., receives) without using the remaining antennas of antenna group 100 and the remaining RF circuits of RF circuit group 110 (wherein they are weighted by one or more weights rxw[i,j_d,k_1] to rxw[i,j_d,k_M] included in the weight vector rxV[i,j_d] associated with the antenna subset S[i,j_d] (step 605)), based on the channel estimates ch[1] to ch[N] associated with antennas a[1] to a[N] of antenna group 100 (step 401), processor 130 of UE 10 can calculate quality assessment Q[i,j_d] and parameter assessment P[i,j_d] (index j_d is j_1 to j_D) Each of the following (i,j_d), wherein the quality assessment Q[i,j_d] and parameter assessment P[i,j_d] are associated with the antenna subset S[i,j_d], which includes one or more antennas a[n_1] to a[n_H] cooperating with one or more RF circuits rfc[k_1] to rfc[k_M].In other words, when UE 10 uses only one or more antennas a[n_1] to a[n_H] and one or more radio frequency circuits rfc[k_1] to rfc[k_M] for communication, and the remaining antennas of antenna group 100 and the remaining radio frequency circuits of radio frequency circuit group 110 are not used, wherein one or more radio frequency circuits rfc[k_1] to rfc[k_M] respectively adopt one or more weights rxw[i,j_d,k_1] to rxw[i,j_d,k_M] contained in the constructed weight vector rxV[i,j_d] (step 605) as one or more weights rxW[k_1] to rxW[k_M] of one or more radio frequency circuits rfc[k_1] to rfc[k_M] (Figure 2 or 3), the processor 130 of UE 10 can calculate the quality assessment Q[i,j_d] and the parameter assessment P. [i,j_d], where the quality assessment Q[i,j_d] and the parameter assessment P[i,j_d] are associated with an antenna subset S[i,j_d] comprising one or more antennas a[n_1] to a[n_H] that cooperate with one or more RF circuits rfc[k_1] to rfc[k_M].

[0098] Step 609: Based on the quality evaluation associated with the antenna subsets in the parent set rxS, the processor 130 can select one of the antenna subsets included in the parent set rxS, update the parent set rxS to the selected antenna subset, and include the selected antenna subset in the candidate pool rxCP. Then, the processor 130 can proceed to step 611. Step 609 can be referred to as the preliminary selection step. Since the parent set rxS can include one or more antenna subsets S[i,j_1] to S[i,j_D], the processor 130 can select one or more antenna subsets S[i,j_1] to S[i,j_D] based on the quality evaluations Q[i,j_1] to Q[i,j_D] associated with the antenna subsets S[i,j_1] to S[i,j_D] respectively. For example, if the quality evaluation Q[i,j_selected_at_i] associated with the antenna subset S[i,j_selected_at_i] is the best among the quality evaluations Q[i,j_1] to Q[i,j_D], then the processor 130 can select the antenna subset S[i,j_selected_at_i] from one or more antenna subsets S[i,j_1] to S[i,j_D] (where the index j_selected_at_i is one of j_1 to j_D). Next, the processor 130 updates the parent set rxS to the selected antenna subset S[i,j_selected_at_i], and can include the selected antenna subset S[i,j_selected_at_i] in the candidate pool rxCP, for example, by appending the antenna subset S[i,j_selected_at_i] to the candidate pool rxCP.

[0099] Step 611: Processor 130 may determine whether to run another iteration of the preliminary antenna selection process 680. If processor 130 determines to run another iteration, processor 130 may return to step 605, where the level index i is updated to another value. On the other hand, if processor 130 determines not to run another iteration, processor may proceed to step 613. Processor 130 may determine whether to run another iteration of the preliminary antenna selection process 680 based on one or more considerations, such as whether index i is below a predefined iteration threshold, and / or whether the quality assessment Q[i,j_selected_at_i] associated with the selected antenna subset S[i,j_selected_at_i] in step 409 is still within a predefined acceptable quality range (e.g., better than a predefined quality threshold), etc. Furthermore, processor 130 may further determine whether to run another iteration based on the results in step 621 below.

[0100] Step 613: After one or more repeated operations in the preliminary selection process of receiving antenna 680, the candidate pool rxCP may include one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] (if Z>1, the indices i1 to iZ are different values ​​from 1 to 1), wherein the above antenna subsets are generated by one or more repeated operations in step 409. One or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] are respectively associated with one or more parameter evaluations P[i1,j_selected_at_i1] to P[iZ,j_selected_at_iZ] calculated in one or more repeated operations in step 407. The processor 130 can evaluate whether P[i1,j_selected_at_i1] to P[iZ, j_selected_at_iZ] meets one or more reception operation requirements based on one or more parameter evaluations. And based on the number of antennas (and / or the number of RF circuits) of each of the one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ], one of the one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] is selected.

[0101] For example, in one embodiment, the processor 130 may select one or more compatible antenna subsets S[#1,j_selected_at_i1] to S[#G,j_selected_at_#G] from one or more antenna subsets S[i1,j_selected_at_i1] to S[iZ,j_selected_at_iZ] contained in the candidate pool rxCP, wherein if G > 1, then the indices #1 to #G are distinct values ​​in i1 to iZ. For each antenna subset S[iz,j_selected_at_iz] (where index iz is each from i1 to iZ) included in the candidate pool rxCP, processor 130 selects antenna subset S[iz,j_selected_at_iz] as a compatible antenna subset if the associated parameter evaluation P[iz,j_selected_at_iz] satisfies the receive operation requirements, and may not select antenna subset S[iz,j_selected_at_iz] as a compatible antenna subset if the associated parameter evaluation P[iz,j_selected_at_iz] does not satisfy the receive operation requirements. Then, processor 130 can select the antenna subset with the lowest number of antennas (and / or RFs) from one or more compatible antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G]. For example, if the number of antennas (and / or the number of RF circuits) of the antenna subset S[ig,j_selected_at_ig] is the lowest among one or more antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G], then the processor 130 can select the antenna subset S[ig,j_selected_at_ig] from one or more compatible antenna subsets S[#1,j_selected_at_#1] to S[#G,j_selected_at_#G] (where the index ig is one of #1 to #G).After selecting an antenna subset S[ig,j_selected_at_ig], the processor 130 can control the UE 10 to use the antennas included in the selected antenna subset S[ig,j_selected_at_ig] and the RF circuitry cooperating with the antennas included in the antenna subset S[ig,j_selected_at_ig] for subsequent wireless communication (e.g., reception), wherein the weighted antennas in the weighted antenna subset S[ig,j_selected_at_ig] are included in the associated weight vector txV[ig,j_selected_at_ig]; and control the UE 10 not to use the remaining antennas (i.e., antennas other than those included in the selected antenna subset S[ig,j_selected_at_ig]) and the RF circuitry cooperating with the remaining antennas.

[0102] Step 621: The processor 130 may monitor one or more reception qualities during the execution of flowchart 600, and may determine whether to execute steps 605 and 607 starting from step 603 and / or 611 based on one or more reception qualities. In one embodiment, one or more reception qualities may involve one or more of the following: channel quality, reception quality, throughput, operating power consumption, whether the downlink data transmission type is dense or sparse, the type of the current user software application, etc. In one embodiment, the processor 130 may also determine what value the level index i should be updated to when step 605 is repeatedly processed from step 611.

[0103] For example, in one embodiment, when one or more reception quality indicators reflect good channel quality, sparse downlink data, and / or the application currently running on UE 10 is not in a hurry to access the network, processor 130 may determine to start step 603 with a higher level index i and / or a smaller parent set rxS including fewer antennas, and / or may determine to repeat step 605 from step 611, wherein the level index i increments, so processor 130 may reduce the number of antennas used for reception and the number of associated RF circuits. As another example, in one embodiment, when one or more reception quality indicators reflect poor channel quality, downlink data density, and / or the application currently running on UE 10 desires network access, processor 130 may determine to begin step 603 with a lower level index i and / or a larger parent set rxS including more antennas, and / or may determine to repeatedly process step 605 starting from step 611, where the level index i is decremented, so processor 130 may increase the number of antennas used for reception and the number of associated RF circuits; or, at step 611, processor 130 may determine not to repeat step 605 after step 611, and then may stop seeking to further reduce the number of antennas used for reception and the number of associated RF circuits. In other words, processor 130 may dynamically and self-adjustingly increase or decrease the number of antennas used for reception and the number of associated RF circuits based on the reception monitoring results of step 621.

[0104] In flowchart 600, since the subset of antennas S[ig,j_selected_at_ig] selected in step 615 is only a subset of the parent set rxS in step 603, the ability to reduce the number of antennas (and RF circuits) used for reception can be indicated from step 603 to step 613.

[0105] It is worth noting that there are various embodiments to represent the flowchart 600 in Figure 6, and the above representation of flowchart 600 may only be one embodiment. Flowchart 600 may have more or fewer steps.

[0106] Figures 7a to 7c depict an example of applying flowchart 600 from Figure 6 to UE 10 from Figure 1. As shown in Figure 7a, in step 401, processor 130 (Figure 1) can obtain a receive weight vector rxV0 after beamforming. The weight vector rxV0 may include weights rxw0[1] to rxw0

[16] associated with the RF circuits rfc[1] to rfc

[16] (Figure 1) cooperating with antennas a[1] to a

[12] , and can be calculated if all antennas a[1] to a

[12] and all RF circuits rfc[1] to rfc

[16] are used for communication.

[0107] In step 603, the processor 130 can set the level index i to 2, set the parent set rxS to the first-level antenna subset S[1,1] including antennas a[1] to a[6] that cooperate with the radio frequency circuits rfc[1] to rfc[8] (Figure 1), and set the candidate pool rxCP to an empty set. By setting the parent set rxS to the antenna subset S[1,1], the processor 130 can select between the second-level antenna subsets S[2,1] and S[2,2] through the first iterative operation of the receiving antenna preliminary selection process 680, which are subsets of the antenna subset S[1,1].

[0108] In step 605, the processor 130 may construct weight vectors rxV[2,1] and rxV[2,2] associated with antenna subsets S[2,1] and S[2,2], respectively. The weight vector rxV[2,1] associated with antenna subset S[2,1] (which may include antennas a[1] to a[4] cooperating with RF circuits rfc[1] to rfc[4]) may include weights rxw[2,1,1] to rxw[2,1,4] associated with RF circuits rfc[1] to rfc[4], respectively. The weight vector rxV[2,2] associated with the antenna subset S[2,2] (which may include antennas a[5] to a[6] that cooperate with RF circuits rfc[5] to rfc[8]) may include weights rxw[2,2,5] to rxw[2,2,8] associated with RF circuits rfc[5] to rfc[8] respectively.

[0109] Referring to Figures 9a and 9b, there are various embodiments for constructing weight vectors rxV[2,1] and rxV[2,2] in step 605 (Figure 7a). According to Figure 9a, in the embodiment for constructing weight vectors rxV[2,1] and rxV[2,2], the processor 130 can obtain the weights rxw0[1] to rxw0[4] and rxw0[5] to rxw0[8] obtained in step 401, and can set the weight vectors rxV[2,1] and rxV[2,2] respectively based on the weights rxw0[1] to rxw0[4] and rxw0[5] to rxw0[8]. The values ​​of the weights rxw[2,1,1] to rxw[2,1,4] and the values ​​of the weights rxw[2,2,5] to rxw[2,2,8] of the weight vector rxV[2,2] can be set to be approximately equal to the values ​​of the weights rxw0[1] to rxw0[4] and rxw0[5] to rxw0[8].

[0110] According to Figure 9b, in the embodiment of constructing weight vectors rxV[2,1] and rxV[2,2], when the UE 10 only uses antennas a[1] to a[4] (and cooperating RF circuits rfc[1] to rfc[4]) and does not need to use the remaining antennas a[5] to a

[12] and the remaining RF circuits rfc[5] to rfc

[16] for communication, the processor 130 can calculate the weights rxw[2,1,1] to rxw[2,1,4] of the weight vector rxV[2,1] by solving the beamforming problem. Similarly, when UE 10 communicates using only antennas a[5] to a[6] (and cooperating radio frequency circuits rfc[5] to rfc[8]) without using the remaining antennas a[1] to a[4], a[7] to a

[12] and the remaining radio frequency circuits rfc[1] to rfc[4] and rfc[9] to rfc

[16] , processor 130 can calculate the weights rxw[2,2,5] to rxw[2,2,8] of weight vector rxV[2,2] by solving the beamforming problem.

[0111] In another embodiment of constructing weight vectors rxV[2,1] and rxV[2,2], according to Figure 9a, processor 130 can set the weights rxw[2,1,1] to rxw[2,1,4] of weight vector rxV[2,1], and can calculate the weights rxw[2,2,5] to rxw[2,2,8] of weight vector rxV[2,2] according to Figure 9b. Alternatively, processor 130 can calculate the weights rxw[2,1,1] to rxw[2,1,4] of weight vector rxV[2,1] according to Figure 9b, and can set the weights rxw[2,2,5] to rxw[2,2,8] of weight vector rxV[2,2] according to Figure 9a.

[0112] In step 607 (Figure 7a), the processor 130 can calculate the quality evaluations Q[2,1] and Q[2,2] and the parameter evaluations P[2,1] and P[2,2] associated with the antenna subsets S[2,1] and S[2,2], respectively. In the case where UE 10 communicates using only antennas a[1] to a[4] and cooperating RF circuits rfc[1] to rfc[4] and not the remaining antennas a[5] to a

[12] and the remaining RF circuits rfc[5] to rfc

[16] (weighted by weights rxw[2,1,1] to rxw[2,1,4] weighted RF circuits rfc[1] to rfc[4]), calculate the quality assessment Q[2,1] and parameter assessment P[2,1] associated with the antenna subset S[2,1] (which may include antennas a[1] to a[4] cooperating with RF circuits rfc[1] to rfc[4)). In the case where UE 10 communicates using only antennas a[5] to a[6] and cooperating RF circuits rfc[5] to rfc[8] and not the remaining antennas a[1] to a[4], a[7] to a

[12] and the remaining RF circuits rfc[1] to rfc[4] and rfc[9] to rfc

[16] (weighted by weights rxw[2,2,5] to rxw[2,2,8] weighted RF circuits rfc[5] to rfc[8]), calculate the quality assessment Q[2,2] and parameter assessment P[2,2] associated with the antenna subset S[2,2] (which may include antennas a[5] to a[6] cooperating with RF circuits rfc[5] to rfc[8).

[0113] In step 609, processor 130 can select one of antenna subsets S[2,1] and S[2,2] by comparing the associated quality assessments Q[2,1] and Q[2,2]. For ease of discussion, assume that quality assessment Q[2,1] is better than quality assessment Q[2,2]. Therefore, processor 130 can select the antenna subset S[2,1] associated with quality assessment Q[2,1], update the parent set rxS to the selected antenna subset S[2,1], and include the antenna subset S[2,1] in the candidate pool rxCP. Then, processor 130 can proceed to step 611.

[0114] In step 611, processor 130 may determine whether to repeat the operation back to step 605. For the sake of discussion, assume that processor 130 decides to return to step 605 for a second repetition, where level index i is updated to three.

[0115] As shown in Figure 7b, in step 605 of the second iteration, since step 615 of the first iteration (Figure 7a) has been updated to include two antenna subsets S[3,1] and S[3,2] as the parent set rxS of the antenna subset S[2,1] is updated to include two antenna subsets S[3,1] and S[3,2], the processor 130 can construct weight vectors rxV[3,1] and rxV[3,2] associated with the antenna subsets S[3,1] and S[3,2], respectively. The weight vector rxV[3,1] associated with the antenna subset S[3,1] (which includes antennas a[1] to a[2] that cooperate with RF circuits rfc[1] to rfc[2]) may include weights rxw[3,1,1] and rxw[3,1,2]. The weight vector rxV[3,2] associated with the antenna subset S[3,2] (which includes antennas a[3] to a[4] that cooperate with RF circuits rfc[3] to rfc[4]) may include weights rxw[3,2,3] and rxw[3,2,4].

[0116] Similar to step 605 of the first repeated operation (Figure 7a), in the embodiment according to Figure 9a, in step 605 of the second repeated operation (Figure 7b), the processor 130 can obtain the previous weights rxw0[1] to rxw0[4] obtained in step 401, and can set the weights rxw[3,1,1], rxw[3,1,2], rxw[3,2,3] and rxw[3,2,4] respectively based on (or substantially equal to) the previous weights rxw0[1] to rxw0[4]. In different embodiments, processor 130 may set weights rxw[3,1,1], rxw[3,1,2], rxw[3,2,3] and rxw[3,2,4] respectively, based on (or substantially equal to) the previous weights rxw[2,1,1] to rxw[2,1,4] constructed in step 605 of the first iterative operation (Figure 7a). In another embodiment, processor 130 may set weights rxw[3,1,1], rxw[3,1,2], rxw[3,2,3] and rxw[3,2,4] based on (or substantially equal to) a combination (e.g., a linear combination) of previous weights rxw[2,1,1] to rxw[2,1,4] and rxw0[1] to rxw0[4]. For example, processor 130 may set weight rxw[3,1,1] to be equal to a linear combination (weighted sum) of previous weights rxw0[1] and rxw[2,1,1], etc.

[0117] In the embodiment according to Figure 9b, in step 605 of the second iteration (Figure 7b), when the UE 10 communicates using only antennas a[1] to a[2] (and the cooperating RF circuits rfc[1] to rfc[2]) without using the remaining antennas a[3] to a

[12] and the remaining RF circuits rfc[3] to rfc

[16] , the processor 130 can calculate the weights rxw[3,1,1] to rxw[3,1,2] of the weight vector rxV[3,1] by solving the beamforming problem. Similarly, when UE 10 communicates using only antennas a[3] to a[4] (and cooperating radio frequency circuits rfc[3] to rfc[4]), without using the remaining antennas a[1] to a[2], a[5] to a

[12] and the remaining radio frequency circuits rfc[1] to rfc[2], rfc[5] to rfc

[16] , processor 130 can calculate the weights rxw[3,2,3] to rxw[3,2,4] of the weight vector rxV[3,2] by solving the beamforming problem.

[0118] In step 607 of the second repeated operation (Figure 7b), the processor 130 can calculate the quality evaluations Q[3,1] and Q[3,2] associated with the antenna subsets S[3,1] and S[3,2], as well as the parameter evaluations P[3,1] and P[3,2]. When UE 10 communicates using only antennas a[1] and a[2] and cooperative RF circuits rfc[1] and rfc[2] (where the cooperative RF circuits rfc[1] and rfc[2] are weighted by weights rxw[3,1,1] and rxw[3,1,2]), without using the remaining antennas a[3] to a

[12] and the remaining RF circuits rfc[3] to rfc

[16] , processor 130 can calculate the quality assessment Q[3,1] and parameter assessment P[3,1] associated with the antenna subset S[3,1] including antennas a[1] and a[2]. Similarly, when UE 10 communicates using only antennas a[3] and a[4] and cooperating RF circuits rfc[3] and rfc[4] without using the remaining antennas a[1] to a[2], a[5] to a

[12] and the remaining RF circuits rfc[1] to rfc[2] and rfc[5] to rfc

[16] (weighted by weights rxw[3,2,3] and rxw[3,2,4]), processor 130 can calculate the quality assessment Q[3,2] and parameter assessment P[3,2] associated with the antenna subset S[3,2] including antennas a[3] and a[4] cooperating with the associated RF circuits rfc[3] and rfc[4].

[0119] In step 609 of the second repeated operation, the processor 130 can select one of the antenna subsets S[3,1] and S[3,2] by comparing the associated quality evaluations Q[3,1] and Q[3,2]. For ease of discussion, it is assumed that the quality evaluation Q[3,2] is better than the quality evaluation Q[3,1]. Therefore, the processor 130 can select the antenna subset S[3,1] associated with the quality evaluation Q[3,1], update the parent set rxS to the selected antenna subset S[3,1], and include the antenna subset S[3,1] in the candidate pool rxCP, proceeding to step 611.

[0120] In step 617 of the second iteration (Figure 7b), processor 130 can determine whether to repeat the iteration back to step 605 to begin another iteration. For ease of discussion, assume that processor 130 decides to perform a third iteration on step 605, so processor 130 can proceed to step 605, where level index i is updated to four.

[0121] As shown in Figure 7c, in step 605 of the third iterative operation, since the target set rxS updated to the antenna subset S[3,1] includes antenna subsets S[4,1] and S[4,2] (Figure 1), the processor 130 can construct weight vectors rxV[4,1] and rxV[4,2] associated with the antenna subsets S[4,1] and S[4,2], respectively. The weight vector rxV[4,1] associated with the antenna subset S[4,1] including antenna a[1] cooperating with RF circuit rfc[1] may include weight txw[4,1,1]. The weight vector rxV[4,2] associated with the antenna subset S[4,2] including antenna a[2] cooperating with RF circuit rfc[2] may include weight rxw[4,2,2].

[0122] Similar to step 605 of the previous iterative operation shown in Figures 7a and 7b, in the embodiment of Figure 9a, in step 605 of the third iterative operation (Figure 7c), the processor 130 can obtain the previous weights rxw0[1] and rxw0[2] obtained in step 401, and can set the weights rxw[4,1,1] and rxw[4,2,2] respectively based on (or substantially equal to) the previous weights rxw0[1] and rxw0[2]. In different embodiments, the processor 130 can set rxw[4,1,1] and rxw[4,2,2] respectively based on (or substantially equal to) the previous weights rxw[3,1,1] and rxw[3,1,2] included in the weight vector rxV[3,1] constructed in step 605 of the second iterative operation (Figure 7b). In another embodiment, the processor 130 may set weights rxw[4,1,1] and rxw[4,2,2] based on (or substantially equal to) the previous weights rxw[2,1,1] and rxw[2,1,2] in the weight vector rxV[2,1] constructed in step 605 of the first iterative operation (Figure 7a). In another embodiment, processor 130 may set weights rxw[4,1,1] and rxw[4,2,2] based on (or substantially equal to) combinations (e.g., linear combinations) of previous weights rxw[2,1,1] and rxw[2,1,2], rxw[3,1,1] and rxw[3,1,2], and rxw0[1] and rxw0[2]; for example, processor 130 may set weight rxw[4,1,1] to be equal to a linear combination (weighted sum) of previous weights rxw0[1], rxw[2,1,1] and rxw[3,1,1], etc.

[0123] In the embodiment according to Figure 9b, in step 605 of the third iteration (Figure 7c), when the UE 10 uses only antenna a[1] (and the corresponding radio frequency circuit rfc[1]) for communication without using the other antennas a[2] to a

[12] and the other radio frequency circuits rfc[2] to rfc

[16] , the processor 130 can calculate the weight rxw[4,1,1] of the weight vector rxV[4,1] by solving the beamforming problem; similarly, when the UE 10 uses only antenna a[2] (and the corresponding radio frequency circuit rfc[2]) for communication without using the other antennas a[1], a[3] to a

[12] and the other radio frequency circuits rfc[1], rfc[3] to rfc

[16] , the processor 130 can calculate the weight rxw[4,2,2] of the weight vector rxV[4,2] by solving the beamforming problem.

[0124] In step 607 of the third iterative operation (Figure 7c), the processor 130 can calculate the quality assessments Q[4,1] and Q[4,2] associated with the antenna subsets S[4,1] and S[4,2], as well as the parameter assessments P[4,1] and P[4,2]. When the UE 10 communicates using only antenna a[1] and the cooperating RF circuit rfc[1] (weighted by weight rxw[4,1,1]) without using the remaining antennas a[2] to a

[12] and the remaining RF circuits rfc[2] to rfc

[16] , the processor 130 can calculate the quality assessment Q[4,1] associated with the antenna subset S[4,1] including the antenna a[1] cooperating with the associated RF circuit rfc[1]. Similarly, when UE 10 communicates using only antenna a[2] and the cooperating RF circuit rfc[2] (weighted by weight rxw[4,2,2]) without using the remaining antennas a[1], a[3] to a

[12] and the remaining RF circuits rfc[1] and rfc[3] to rfc

[16] , processor 130 can calculate a quality assessment Q[4,2] associated with the antenna subset S[4,2], which includes antenna a[2] cooperating with the associated RF circuit rfc[2].

[0125] As shown in Figure 7c, in step 409 of the third iterative operation, the processor 130 can select one of the antenna subsets S[4,1] and S[4,2] by comparing the associated quality evaluations Q[4,1] and Q[4,2]. For ease of discussion, assuming that the quality evaluation Q[4,1] is better than the quality evaluation Q[4,2], the processor 130 can select the antenna subset S[4,1], update the parent set rxS to the selected antenna subset S[4,1], include the selected antenna subset S[4,1] in the candidate pool rxCP, and proceed to step 611. After the three iterative operations in step 609, the candidate pool rxCP can include antenna subsets S[2,1], S[3,1] and S[4,1].

[0126] As shown in Figure 7c, during the third iteration of step 611, processor 130 can determine whether to repeat the iteration back to step 605 to begin another iteration. Since level index i=4 has reached the highest level of all antenna subsets from level 0 antenna subset S[0,1] to level 4 antenna subsets S[4,1] to S[4,12] (Figure 1), processor 130 can decide not to repeat step 605 and can proceed to step 613.

[0127] As shown in Figure 7c, in the third iteration of step 613, assuming that the parameter evaluation of each of the antenna subsets S[2,1], S[3,1] and S[4,1] included in the candidate pool rxCP satisfies the reception operation requirements, since the number of antennas in the antenna subset S[4,1] (equal to 1) is lower than the number of antennas in the antenna subsets S[2,1] and S[3,1] (equal to 4 and 2 respectively), the processor 130 can select the antenna subset S[4,1] from the antenna subsets S[2,1], S[3,1] and S[4,1]. Then, the processor 130 can enable the UE 10 to use antenna a[1] included in the antenna subset S[4,1], and the cooperative RF circuit rfc[1] weighted by weight rxw[4,1,1] included in the weight vector rxV[4,1] for subsequent wireless communication (such as reception); the UE 10 does not use the remaining antennas a[2] to a

[12] and the remaining RF circuit rfc[2] to rfc

[16] , and thus the UE 10 can reduce power consumption.

[0128] In summary, the present invention can provide a method (e.g., flowcharts 400 and / or 600 in Figures 4 and / or 6), a UE, and / or a processor that can hierarchically and self-adjustably select fewer antennas from all antennas in an antenna group (e.g., an array) for wireless communication, such as transmission (e.g., for uplink) and / or reception (e.g., for downlink), thus effectively reducing the power consumption of wireless communication. In one embodiment, the method according to the invention can be automatically executed by the UE (e.g., a processor) without user intervention, participation, and / or awareness. During antenna selection, the present invention can determine whether a subset of antennas (e.g., S[i,j] in Figures 4 or 6) can be selected based on associated quality assessments (e.g., Q[i,j]) and / or parameter assessments (e.g., P[i,j]), thus ensuring that antenna selection does not degrade communication quality and / or impair requirements that may be related to regulations and / or wireless communication protocols, technical specifications, and / or standards. The method according to the present invention can encompass a beamforming process (e.g., step 401 in Figure 4 or 6), a preliminary transmit antenna selection process (e.g., 480 in Figure 4), a high-level transmit antenna selection step (e.g., step 413 in Figure 4), a preliminary receive antenna selection process (e.g., 680 in Figure 6), and a high-level receive antenna selection step (e.g., step 613 in Figure 6). In one embodiment, when using all antennas in the antenna set, the UE can perform the beamforming process based on only one pilot (occupying one or more consecutive symbols) to calculate channel estimates (e.g., ch[1] to ch[N] in step 401 in Figure 4 or 6) and / or weight vectors (e.g., txV0 and / or rxV0 in step 401 in Figure 4 or 6), and then the UE (processor) can perform the preliminary transmit and receive antenna selection processes based on the results of the beamforming process (channel estimates and / or weight vectors). As an example, a UE (processor) can select one or more antennas to receive and measure one or more signal blocks, applying the antenna selection of the present invention to radio resource management (RRM) measurements. Each signal block may include a synchronization signal (SS) and a physical broadcast channel (PBCH) signal packaged into an SS / PBCH block (SSB), as defined by the 3GPP (3rd Generation Partnership Project). Since the antenna selection according to the present invention is based on channel estimation generated by the beamforming process, the antenna selection according to the present invention can ensure the robustness of RRM measurements.

[0129] According to the present invention, antenna selection (e.g., transmission antenna selection process) can select to use fewer than all antennas (and fewer than all cooperating RF circuits) for data transmission (e.g., uplink), and thus can reduce the power consumption of the transmitting UE without affecting the user experience, for example, without suffering uplink throughput loss, and / or without compromising compliance with operational requirements (e.g., transmission power requirements and / or radiation exposure regulations). The antenna selection (e.g., the receive antenna selection process) according to the present invention can dynamically and self-adjust based on channel quality, receive quality, throughput, runtime power consumption, whether the downlink data transmission type is dense or sparse, and / or the type of the current user / system software application, such as whether each user / system application involves intensive network activity (e.g., video and / or audio streaming, etc.) or moderate network activity (e.g., internet browsing and / or SMS, etc.), selecting to use fewer than all antennas (and fewer than all cooperating RF circuits) for data reception (e.g., downlink). Therefore, the receive power consumption of the UE can be reduced without affecting the user experience, e.g., without suffering downlink throughput loss. For example, when channel quality degrades, downlink data is intensive, and / or one or more currently running applications require intensive network activity, the antenna selection according to the present invention can select to use more antennas (and more cooperating RF circuits); on the other hand, when channel quality improves, downlink data is sparse, and / or the currently running applications only require low network activity, the antenna selection according to the present invention can select to use fewer antennas (and fewer cooperating RF circuits).

[0130] Although the invention has been described by way of exemplary means based on preferred embodiments, it is to be understood that the invention is not limited thereto. Those skilled in the art will be able to make various changes and modifications without departing from the scope and spirit of the invention. Therefore, the scope of the invention should be defined and protected by the appended claims and their equivalents. [Simplified Explanation of the Diagram]

[0026] The invention can be more fully understood by reading the following detailed description with reference to the accompanying drawings. It should be understood that these drawings are not drawn to scale according to standard industry practice. In fact, the dimensions of the elements in the drawings are allowed to be enlarged or reduced for clarity. This means that many specific details, relationships, and methods are disclosed to provide a complete understanding of the invention. Figure 1 is an exemplary schematic diagram of a UE according to an embodiment of the invention; the UE may include an antenna group having a plurality of antennas, and may also include a plurality of radio frequency (RF) circuits associated with the plurality of antennas respectively. Figure 2 is a schematic diagram of a user equipment according to an embodiment of the invention. Figure 3 schematically depicts the RF circuitry. Figure 4 illustrates a flowchart of transmit antenna selection according to an embodiment of the invention. Figures 5a to 5e illustrate examples of the UE in Figure 1 performing transmit antenna selection in Figure 4. Figure 6 illustrates a flowchart of receive antenna selection according to an embodiment of the invention. Figures 7a to 7c illustrate examples of the UE in Figure 1 performing receive antenna selection in Figure 6. Figures 8a and 8b illustrate two examples of the steps for constructing a weight vector in the flowchart shown in Figure 4 according to two embodiments of the invention. Figures 9a and 9b illustrate two examples of the steps for constructing a weight vector in the flowchart shown in Figure 6, according to two embodiments of the present invention.

Claims

1. A method for selecting an antenna for user equipment, wherein, The user equipment includes a plurality of antennas for wireless communication and performs the antenna selection method, which includes: performing a quality assessment step, including: calculating one or more quality assessments respectively associated with one or more first antenna subsets; performing a preliminary selection step, including: selecting one of the one or more first antenna subsets based on the one or more quality assessments; wherein: each of the one or more first antenna subsets includes one or more of the plurality of antennas; and when the one or more of the plurality of antennas included in the associated first antenna subsets are used for communication, calculating each of the one or more quality assessments associated with one of the one or more first antenna subsets.

2. The user equipment antenna selection method as described in claim 1, wherein, The method further includes: prior to the quality assessment step, calculating a plurality of channel estimates associated with the plurality of antennas, wherein: when calculating the one or more quality assessments in the quality assessment step, the one or more quality assessments are calculated based on the plurality of channel estimates.

3. The user equipment antenna selection method as described in claim 1, wherein, The method further includes: prior to the quality assessment step, performing a weight construction step, including: constructing one or more current-level weight vectors associated with the one or more first antenna subsets, wherein: each of the one or more current-level weight vectors associated with one of the one or more first antenna subsets includes one or more current-level weights associated with the one or more antennas included in the associated first antenna subset; and each of the one or more quality assessments is associated with one of the one or more first antenna subsets and is calculated if the one or more antennas included in the associated first antenna subset are used for communication, wherein the one or more current-level weights included in the associated current-level weight vectors weight the one or more antennas.

4. The user equipment antenna selection method as described in claim 3, wherein, When constructing a specific current level weight vector among one or more current level weight vectors, wherein the specific current level weight vector is associated with a specific first antenna subset among one or more first antenna subsets, one or more previous weights are obtained, and the one or more current level weights included in the specific current level weight vector are set according to the one or more previous weights; and the one or more previous weights are associated with the one or more antennas among the plurality of antennas included in the specific first antenna subset, and are recorded prior to the weight construction step.

5. The user equipment antenna selection method as described in claim 3, wherein, When constructing a specific current level weight vector among one or more current level weight vectors, wherein the specific current level weight vector is associated with a specific first antenna subset among one or more first antenna subsets, the one or more current level weights included in the specific current level weight vector are calculated by solving the beamforming optimization problem when using one or more antennas including the plurality of antennas in the specific first antenna subset.

6. The user equipment antenna selection method as described in claim 1, wherein, The method further includes performing a high-level selection step after performing the preliminary selection step; wherein the high-level selection step may include selecting one of the one or more second antenna subsets from a candidate pool comprising one or more second antenna subsets based on one or more parameter evaluations; wherein the one or more parameter evaluations are respectively associated with the one or more second antenna subsets, and each of the one or more second antenna subsets comprises one or more of the plurality of antennas; wherein the preliminary selection step further includes including the selected one of the one or more first antenna subsets in the candidate pool after selecting one of the one or more first antenna subsets based on the one or more quality evaluations.

7. The user equipment antenna selection method as described in claim 6, wherein, The method further includes: prior to the advanced selection step, calculating one or more parameter evaluations associated with the one or more subsets of second antennas respectively; each of the one or more parameter evaluations is associated with one or more subsets of second antennas and includes one or more parameters of the user equipment, and is calculated when the one or more antennas included in the associated second antenna subsets are used for communication.

8. The user equipment antenna selection method as described in claim 6, wherein, The step of selecting one of the one or more subsets of second antennas based on the one or more parameter evaluations includes: selecting one or more compatible antenna subsets from the one or more subsets of second antennas by selecting the specific second antenna subset as one of the one or more compatible antenna subsets if a specific parameter evaluation in the one or more parameter evaluations associated with a particular second antenna subset satisfies one or more operational requirements; and selecting one of the one or more compatible antenna subsets based on one or more counts respectively associated with the one or more compatible antenna subsets; wherein each of the one or more counts is associated with one of the one or more compatible antenna subsets and involves the count of the one or more antennas included in the associated one of the one or more compatible antenna subsets.

9. The user equipment antenna selection method as described in claim 8, wherein, The one or more operational requirements involve one or more of the following: maximum power reduction, power management maximum power reduction, error vector magnitude, and time-averaged power density.

10. The user equipment antenna selection method as described in claim 8, wherein, When selecting one of the one or more compatible antenna subsets based on the one or more counts associated with the one or more compatible antenna subsets respectively, the compatible antenna subset associated with the lowest count is selected from the one or more compatible antenna subsets.

11. The user equipment antenna selection method as described in claim 8, wherein, The method further includes: after selecting one of the one or more compatible antenna subsets, causing the user equipment to use the one or more antennas in the selected antenna subset included in the one or more compatible antenna subsets for subsequent communication.

12. The user equipment antenna selection method as described in claim 11, wherein, The method further includes: when the user equipment uses one or more antennas included in the selected antenna subset of the one or more compatible antenna subsets for subsequent communication, the user equipment further excludes the remaining antennas of the plurality of antennas.

13. The user equipment antenna selection method as described in claim 6, wherein, Each of the one or more parameter evaluations is associated with one of the one or more second antenna subsets and relates to the power of one or more power amplifiers of the one or more antennas included in the associated antenna subset of the one or more second antenna subsets.

14. The user equipment antenna selection method as described in claim 1, wherein, The method further includes: after selecting one of the one or more antenna subsets based on the one or more quality assessments, repeatedly performing the quality assessment step and the primary selection step by: calculating one or more next-level quality assessments associated with one or more next-level antenna subsets; and selecting one or more next-level antenna subsets based on the one or more next-level quality assessments, wherein: each of the one or more next-level antenna subsets includes one or more of the plurality of antennas; each of the one or more next-level quality assessments is associated with one of the one or more next-level antenna subsets and is calculated when using the one or more antennas included in the associated next-level antenna subset for communication; and the count of the one or more antennas included in each of the one or more next-level antenna subsets is not greater than the count of the one or more antennas included in the selected one of the one or more first antenna subsets.

15. The user equipment antenna selection method as described in claim 14, wherein, At least one of the one or more next-level antenna subsets is a strict subset of the selected one of the one or more first antenna subsets.

16. The user equipment antenna selection method as described in claim 1, wherein, The method further includes: monitoring one or more reception qualities; and determining, based on the one or more reception qualities, whether to repeat the quality assessment step and the preliminary selection step before repeatedly calculating the quality assessment step and the preliminary selection step.

17. The user equipment antenna selection method as described in claim 1, wherein, The method further includes: monitoring one or more reception qualities; and determining, based on the one or more reception qualities, whether to perform the quality assessment step and the preliminary selection step before performing the quality assessment step and the preliminary selection step.

18. The user equipment antenna selection method as described in claim 17, wherein, The one or more receiver quality parameters involve one or more of the following: channel quality, receiver quality, throughput, runtime power consumption, whether the downlink data transmission type is dense or sparse, and the type of the current user application.

19. The user equipment antenna selection method as described in claim 1, wherein, Each of the one or more quality assessments includes one or more communication qualities, wherein the one or more communication qualities are related to one or more of the following: reference signal received power, reference signal received quality, received signal strength index, and signal-to-interference-to-noise ratio.

20. The user equipment antenna selection method as described in claim 1, wherein, Two antenna subsets in one or more antenna subsets are mutually exclusive.

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