Pi / 2-bpsk for initial access

Abstract

Methods and apparatus, including computer program products, are provided for pi / 2 BPSK initial access. In some example embodiments, a method can be provided that includes receiving, at a user equipment, information indicating network support for initial network access based on a pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; and in response to the received system information, performing initial network access by at least sending a connection request based on the pi / 2-BPSK modulation and coding scheme. Related systems, methods, and articles of manufacture are also described.

Description

Technical Field

[0001] The topics described in this article relate to cellular systems, and specifically to initial access. Background Technology

[0002] In 3GPP, the New Radio (NR) provides pi / 2 binary phase shift keying (π / 2-BPSK) in the uplink (UL) path as the lowest-order (e.g., minimum number of bits per symbol) digital modulation among a set of digital modulations used for uplink data transmission. pi / 2-BPSK can be generated from a standard BPSK signal by multiplying the symbol sequence with a rotated phasor whose phase increment per symbol period is pi / 2. This pi / 2-BPSK can achieve the same bit error rate performance as BPSK over linear channels, but it can exhibit smaller envelope variations. Summary of the Invention

[0003] Methods and apparatus, including computer program products, are provided for initial access to pi / 2BPSK.

[0004] In some example embodiments, a method may be provided that includes receiving at a user equipment information indicating network support for initial network access based on a pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; and, in response to the received system information, performing initial network access by at least sending a connection request based on the pi / 2-BPSK modulation and coding scheme.

[0005] In some variations, one or more features disclosed herein (including the following features) may optionally be included in any feasible combination. This information may be received as system information transmitted before the Physical Random Access Channel (PRACH) preamble is transmitted by the user equipment. This information may be received from the network as a random access response including uplink grant from the base station. The received information may also indicate network support for the pi / 2-BPSK demodulation reference signal. The connection request may include a Radio Resource Control Connection Request message transmitted via the Physical Uplink Shared Channel based on the pi / 2-BPSK modulation and coding scheme and the demodulation reference signal. The demodulation reference signal may include a pi / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal. A Physical Random Access Channel (PRACH) preamble indicating the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal supported by the user equipment may be transmitted. The received information may also indicate one or more of the following: whether the power boost is used to perform random access channel access using the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal; whether the power boost is used for initial network access or retransmission; whether the power boost is used for hybrid automatic repeat request retransmission; or one or more modulation and coding scheme indices suitable for pi / 2BPSK transmission.

[0006] In some example embodiments, a method may be provided that includes sending information to a user equipment indicating network support for initial network access based on a pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; receiving initial network access including a connection request from the user equipment via a physical uplink shared channel; and detecting that the connection request is transmitted using pi / 2-BPSK modulation and coding.

[0007] In some variations, one or more features disclosed herein (including the following features) may optionally be included in any feasible combination. In response to detection, a connection establishment message may be used in response to a connection request. This message may be sent as at least one of the following: system information transmitted before the Physical Random Access Channel (PRACH) preamble is sent by the user equipment, or a random access response including uplink authorization from the base station. The connection request may include a Radio Resource Control (RRC) Connection Request message carried via the Physical Uplink Shared Channel using a pi / 2-BPSK modulation and coding scheme and a demodulation reference signal. The demodulation reference signal may include a pi / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal sequence. Information indicating network support may also indicate support for the pi / 2-BPSK demodulation reference signal. A Physical Random Access Channel (PRACH) preamble indicating that the user equipment supports the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal may be received. The transmitted information may also indicate one or more of the following: whether the power boost was used for random access channel access using the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal; whether the power boost was used for initial network access or retransmission; whether the power boost was used for hybrid automatic repeat request retransmission; or one or more modulation and coding scheme indices suitable for pi / 2BPSK transmission. Detection may also include detecting that the connection request is transmitted using the pi / 2-BPSK modulation and coding scheme based on at least one of the correlation of the demodulation reference signal sequence indicating the pi / 2-BPSK modulation and coding scheme or the cyclic redundancy check of the demodulation reference signal sequence. In response to a failure of the cyclic redundancy check, an uplink grant allocation may be sent to the user equipment, the uplink grant including a downlink control information format for retransmission using a new radio network temporary identifier for pi / 2-BPSK-based retransmissions.

[0008] Depending on the desired configuration, the above aspects and features can be implemented in systems, apparatus, methods, and / or articles. Details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the description below. The features and advantages of the subject matter described herein will be apparent from the specification, drawings, and claims. Attached Figure Description

[0009] In the attached diagram,

[0010] Figure 1A Examples of the initial access process to the network according to some example embodiments are described;

[0011] Figure 1BExamples of procedures for accessing a network using pi / 2-BPSK and pi / 2-BPSK-DMRS at a user equipment are described according to some example embodiments;

[0012] Figure 1C Examples of procedures for implementing access at a base station using pi / 2-BPSK and pi / 2-BPSK-DMRS, according to some example embodiments, are described;

[0013] Figure 2A An example of initial access according to some example embodiments is depicted, in which one UE supports the use of pi / 2-BPSK, while another UE 210 does not support the use of pi / 2-BPSK;

[0014] Figure 2B Another example of initial access according to some example embodiments is described, in which one UE supports the use of pi / 2-BPSK, while another UE does not support the use of pi / 2-BPSK;

[0015] Figure 3 Examples of network nodes according to some example embodiments are depicted; and

[0016] Figure 4 Examples of apparatuses according to some example embodiments are depicted.

[0017] The same labels are used to indicate the same or similar items in the attached figures. Detailed Implementation

[0018] As mentioned above, NR systems (also known as 5G systems) can provide support for the pi / 2-BPSK modulation and coding scheme (MCS), but the pi / 2-BPSK MCS is an optional feature for user equipment (UE), so not all UEs can choose to support pi / 2-BPSK. When using the pi / 2-BPSK MCS to obtain improved peak-to-average power ratio performance (PAPR) and a correspondingly smaller maximum power reduction (MPR) value, as well as even higher average transmit power levels, the UE can optionally support spectrum shaping. Furthermore, when using pi / 2-BPSK, the UE can also support a nominal 3dB power boost (reference power of 26dBm, instead of the typical 23dBm for a power class 3 UE, as shown in Note 1 of Table 1 below). In this case, the spectrum flatness requirement is relaxed, and the maximum power reduction value is increased. This can reduce the actual power difference within internal resource blocks (RBs) to as high as approximately 2.8dB, while at the band edges, there is no power difference. Table 1 below (which is reproduced from 3GPP TS38.101-1) depicts the MPR for power class 3 of pi / 2-BPSK compared to other modulation and coding schemes.

[0019] Table 1

[0020]

[0021]

[0022] For example, uplink coverage of the UE can be further improved by using pi / 2BPSK and power boost, which is the lowest 3GPP mandatory (i.e., not optional) modulation order in the uplink. This pi / 2BPSK-related improvement is likely due to simpler modulation that is easier to demodulate correctly (although the bit rate per symbol is halved with pi / 2BPSK compared to QPSK), and increased transmission power. The use of pi / 2BPSK and power boost for uplink coverage enhancement is particularly useful for large cell deployments (such as large cell rural deployments) where the UE is located at the edge of the cell.

[0023] In 3GPP Release 15 (Rel-15), demodulation reference signal (DMRS) symbols (generated based on Zadoff-Chu sequences) may offer poorer peak-to-average power ratio (PAPR) performance compared to pi / 2-BPSK modulated data symbols. This can result in a larger maximum power reduction and a lower average achievable transmission power than required by the data symbols. In 3GPP Release 16 (Rel-16), pi / 2-BPSK modulated DMRS can be used with pi / 2-BPSK modulated Physical Uplink Shared Channel (PUSCH). Because this new DMRS design is based on a pseudo-random sequence modulated by pi / 2-BPSK, the PAPR performance can be similar to that of the data symbols. Therefore, an overall performance improvement in MPR requirements can be achieved. For example, pi / 2-BPSK DMRS can provide a 2-3 dB MPR improvement (e.g., a smaller MPR) compared to Rel-15 DMRS.

[0024] For example, the UE's initial access procedure to the network (also known as the Random Access Channel or RACH procedure) is used for connection establishment. Figure 1A An example of a RACH procedure for initial access performed by a UE 110 in a network including a base station (e.g., a 5G gNB-type base station 150) is depicted.

[0025] For UE 110, the initial network access procedure involves a random access channel (RACH) transmission (see, for example, Msg1 at 102, Physical Random Access Channel (PRACH) preamble), followed by a first uplink message (Msg3, Radio Resource Control (RRC) connection request) transmission on the Physical Uplink Shared Channel (PUSCH) at 106. This uplink transmission on the PUSCH is scheduled using the uplink grant provided at 104 in a random access response message (Msg2) provided by a network such as base station 150. The Msg2 uplink grant (which is provided for initial access) includes the modulation and coding scheme (MCS) and PUSCH resource location for the UE's Msg3 transmission. Furthermore, the base station can respond at 108 with a fourth message, Msg4, which has an RRC connection establishment including a contention resolution identifier. However, Figure 1A The process at Msg3 may not enable the UE's initial access transmission to be pi / 2-BPSK, because pi / 2-BPSK is an optional UE capability, and the network or base station may not know whether the UE can use this feature during the initial access.

[0026] In some example embodiments, a method is provided for indicating pi / 2-BPSKPUSCH support prior to initial access at Msg3.

[0027] In some example embodiments, pi / 2-BPSKDMRS for PUSCH transmission during the initial access of the UE is provided, such as Msg3 RRC connection requests to the network.

[0028] In some example embodiments, network signaling can be used to allow the UE to transmit Msg3 using a pi / 2-BPSK modulation and coding scheme on the PUSCH, and / or to use pi / 2BPSK modulation on DMRS sequences also transmitted on the PUSCH. As described above, the use of pi / 2-BPSK MCS and / or pi / 2-BPSK DMRS for Msg3 transmission can improve coverage performance during the UE's initial access procedure, such as in the case of cell-edge UEs in large cell deployments.

[0029] When using pi / 2-BPSK DMRS sequences, the DMRS sequences used for pi / 2-BPSK will differ from other modulation and coding schemes, and are therefore detectable. In other words, the sequences (e.g., codes) used for pi / 2-BPSK DMRS will be different sequences compared to those used for QPSK DMRS. Therefore, networks such as network nodes (e.g., base stations) can detect the DMRS sequences used for pi / 2-BPSK. Network nodes can also distinguish transmission types based on two different DMRS sequences of the same type (e.g., between two different pi / 2BPSK DMRS sequences or two different Zadoff-Chu (ZC) DMRS sequences).

[0030] In some example embodiments, the network, and in particular the base station, can detect differences between pi / 2-BPSK MCS transmissions and QPSK MCS transmissions based on the correlation between the received DMRS and the two types of DMRS. For example, the base station can correlate a sequence of pi / 2-BPSK DMRS used with one MCS for data transmission using pi / 2BPSK modulation and a sequence of ZC DMRS used with another MCS for data transmission on the PUSCH using QPSK modulation to detect which of the two DMRS sequences is present and, from this, determine which of the two MCSs (e.g., pi / 2BPSK or QPSK) was used for data transmission on the PUSCH. Alternatively or additionally, the base station can detect demodulation attempts by first assuming one of the two transmission modes for DMRS and PUSCH, and if the PUSCH CRC fails, the base station then attempts to assume the UE used the other transmission mode.

[0031] Figure 1B Examples of the initial network access process at the UE are described according to some example embodiments. Figure 1B The description also references Figure 1A .

[0032] At 120, UE 110 can receive information indicating network support for initial UE access based on pi / 2-BPSK MCS and pi / 2-BPSK-DMRS. For example, the UE can receive information from base station 150 indicating that: (1) initial access (such as Msg3 transmitted via PUSCH at 106) can be configured with a pi / 2-BPSK modulation and coding scheme, and / or (2) a pseudo-random pi / 2-BPSK modulated bit sequence can be used as a DMRS sequence for Msg3 PUSCH demodulation. For example, the PUSCH data symbols can be pi / 2BPSK modulated, and the DMRS sequence can be of a specific type indicating pi / 2BPSK. For example, the DMRS can be a pseudo-random bit sequence indicating pi / 2BPSK, although the DMRS can also be a ZC sequence (but in either case, the sequence indicates pi / 2BPSK instead of QPSK). As described above, the base station receiver uses the DMRS sequence (known) to estimate the UE's radio channel and demodulate the PUSCH data symbols.

[0033] The aforementioned information indicating network support for pi / 2BPSK (which can be received at 120) can be sent to the UE in a variety of ways.

[0034] In some embodiments, information indicating support for pi / 2BPSK can be transmitted to the UE via a broadcast channel as part of system information sent to the UE before transmitting Msg1. For example, before transmitting the Msg1 preamble at 102, the base station can transmit the system information indicating support for pi / 2BPSK as a broadcast on the downlink.

[0035] In some embodiments, information indicating support for pi / 2BPSK can be transmitted at 104 via the RAR of Msg2. For example, the network can control pi / 2 access in a more dynamic manner by including information indicating network support for pi / 2BPSK in the RAR (e.g., Msg2), so that the UE (if it supports pi / 2BPSK) can continue with initial access, for example, at Msg3. When the RAR is used to carry the pi / 2BPSK indication, the system information broadcast (which is transmitted before Msg1) can also include the pi / 2BPSK support indication.

[0036] To further illustrate, the random access response 104 from base station 150 may include an indication that the network supports initial UE access based on pi / 2-BPSK MCS and / or pi / 2-BPSK-DMRS. This indication may be in the form of an uplink grant (provided in Msg2) indicating that at Msg3 the UE may use pi / 2-BPSK MCS and / or pi / 2-BPSK-DMRS for initial access.

[0037] In some example embodiments, gNB 150 may also indicate to the UE a range of initial MCS values ​​applicable to pi / 2-BPSK transmissions. For example, information received by UE 110 at 120 may indicate a list of MCS values ​​(or indices of these values) applicable to pi / 2-BPSK MCS transmissions. This may be in the form of MCS indices, examples of which are shown in Tables 3 and 4 below.

[0038] At 125, the UE can perform initial network access to the network using the pi / 2-BPSK MCS and / or pi / 2-BPSK-DMRS. In response to receiving an uplink grant as indicated at 120, the UE can perform initial access by transmitting an RRC connection request (e.g., Msg3 with pi / 2-BPSK MCS) and pi / 2-BPSK-DMRS to base station 150 via PUSCH.

[0039] Figure 1C Examples of the initial network access process at a base station according to some example embodiments are described. Figure 1B The description also references Figure 1A .

[0040] At 130, a network such as base station 150 can send information to UE 110, including an indication that the network supports initial UE access based on pi / 2-BPSK MCS and pi / 2-BPSK-DMRS. As described above, base station 150 can send this indication in various ways, such as via system information sent to the UE before sending Msg1 and / or via the RAR of Msg2 at 104. In some example embodiments, the information sent at 130 can indicate a list of MCS values ​​applicable to the pi / 2-BPSK MCS transmission. This can be in the form of an MCS index, examples of which are shown in Tables 3 and 4 below.

[0041] At 135, base station 150 can receive initial access messages from UE 110 using pi / 2-BPSK MCS and / or pi / 2-BPSK-DMRS. For example, base station 150 can receive Msg3 via PUSCH using pi / 2-BPSK MCS and pi / 2-BPSK-DMRS. Base station 150 can detect that the UE uses pi / 2-BPSK as pi / 2-BPSK-DMRS, which can be detected as different from QPSK DMRS.

[0042] In some example embodiments, a UE supporting pi / 2-BPSK and pi / 2-BPSK-DMRS may use pi / 2-BPSK to transmit Msg3 if the uplink grant provided in the random access response (e.g., the RAR at Msg2) indicates a specific MCS (e.g., an MCS reserved or designated for this purpose). The RAR (which includes the uplink grant for Msg3 transmission by the UE) also includes the MCS to be used by the UE. For example, the UE may use the MCS as pi / 2-BPSK when a subset of the MCS (which may be indicated by system information) is sent in the uplink grant.

[0043] If pi / 2-BPSK transmission for initial access can be supported, the UE may also use power-boosted transmission for this initial access if needed. The power-boosting operation for initial access can be controlled and configured by the network to avoid autonomous increases in UE transmission power for initial access (which could lead to increased inter-cell interference). As described above, base station 150 can send this power-boosting indication in various ways, such as via system information sent to the UE via Msg2's RAR at 104.

[0044] Regarding enabling power boost for pi / 2-BPSK transmission for initial access, the network may send an indication to the UE whether the UE can use power boost transmission for RACH access. Alternatively or additionally, the network may send an indication to the UE that the UE can consider power boost only for RACH retransmissions without considering power boost for initial transmissions. Alternatively or additionally, the network may send an indication to the UE whether hybrid automatic repeat request (HARQ) retransmissions over PUSCH can use power boost to transmit at increased power. Alternatively or additionally, the network may send an indication to the UE of which MCS index is suitable for pi / 2BPSK transmission. As described above, base station 150 may send this power boost indication in various ways, such as via system information sent to the UE via Msg2's RAR at 104. As described above, these indications can be provided to the UE by the network or base station in various ways, such as via a random access response (e.g., Msg2 at 104), which is included in system information sent to the UE prior to Msg1, carried by the Physical Downlink Shared Channel (PDSCH), Physical Broadcast Channel (PBCH), or other types of downlink.

[0045] Refer again Figure 1A The uplink grant information included in the Msg2 Random Access Response (RAR) may include one or more of the fields depicted in Table 2 below (which is reproduced from 3GPP TS 38.213). Referring to Table 2, four bits are reserved to indicate the MCS to be used for Msg3.

[0046] Table 2: Size of Random Access Response Authorization Content Field [TS38.213]

[0047] RAR Authorization Fields Number of digits Frequency hopping flag 1 PUSCH frequency resource allocation 14 PUSCH time resource allocation 4 MCS 4 PUSCH's TPC command 3 CSI Request 1

[0048] According to some example embodiments, if the PRACH preamble is used to detect the UE's ability to use pi / 2BPSK, the currently reserved MCS values ​​(see Tables 3 and 4 below, reproduced from TS 38.214) can be used to schedule pi / 2BPSK. If a UE capable of using pi / 2-BPSK uses a separate preamble, the network will know the pi / 2-BPSK capability based on the preamble itself. In this case, the UE can use pi / 2-BPSK when the entry highlighted in the MCS index is sent in Msg2. Here, the UE does not need to signal its capability. Sending the preamble (which is reserved for this type of pi / 2BPSK UE) is an indication to the network that the UE is capable of using the pi / 2BPSK MCS. Depending on the UE type determined by the Msg3 DMRS type, the set of lowest MCS values ​​may result in the UE being granted uplink access authorization at 104 with either QPSK or pi / 2BPSK transmissions (with or without power boost). If tp-pi2BPSK is configured, then q = 1 (e.g., using pi / 2BPSK); otherwise, q = 2 (e.g., using QPSK), where Table 3 shows the default modulation order and code rate when the MCS index is 0 or 1. For other MCS indices, the operation can remain unchanged. The network can also be configured to use other MCS tables for even lower data rates (and greater coverage), where the lowest 6 MCSs can use pi / 2BPSK. Furthermore, the network can configure which MCSs are suitable for pi / 2-BPSK in the system information.

[0049] Table 3: Table 6.1.4.1-1: PUSCH MCS Index Table with Transform Precoding and 64QAM [Table 6.1.4.1-1 of TS38.214]

[0050]

[0051] Table 4: MCS Index Table for PUSCH with Transform Precoding and 64QAM [Table 6.1.4.1-2 of TS38.214:]

[0052]

[0053] Figure 2AAn example of initial network access is depicted, wherein one of UEs 110 supports (e.g., is configurable with) pi / 2-BPSK MCS and pi / 2-BPSK DMRS for PUSCH, while another UE 210 does not support pi / 2-BPSK MCS and pi / 2-BPSK DMRS. Since there is another UE 210 that can receive the same uplink grant on PUSCH as UE 110 for contention-based RACH access, gNB 150 can (1) receive Msg3 106 from pi / 2-BPSK UE 110 at 106, which is sent along with pi / 2-BPSK MCS including pi / 2-BPSK DMRS, and can also (2) receive another Msg3 from UE 210 at 206 using QPSK (which corresponds to the actual MCS index interpretation of the MCS table). For example, UE 110 can receive uplink grants that include MCS index 0 (see Table 3, for example), and UE 210 can receive uplink grants that include multiple MCS indexes 0 (see Table 3, for example). Figure 3 This is because pi / 2BPSK and QPSK share the same index. However, UE 110 (which supports pi / 2BPSK) will send Msg3 based on the MCS 0 index as the pi / 2BPSK MCS, while UE 210 (which does not support pi / 2BPSK and uses QPSK instead) will send Msg3 based on the MCS 0 index as the QPSK MCS. Due to the shared MCS index, the base station may need to detect whether the UE is using pi / 2BPSK.

[0054] At 212A, gNB 150 can eliminate ambiguity between QPSK and pi / 2-BPSK based on the received DMRS and / or based on CRC checksums (e.g., using different MCS decoding) to identify the MCS as pi / 2-BPSK at 214. For example, gNB can (1) perform a correlation of the received DMRS with both types of DMRS for pi / 2-BPSK and QPSK, or (2) attempt demodulation first, assuming one of the two transmission modes, and if the PUSCH CRC fails, attempt again, assuming the UE is using the other transmission mode. In this way, gNB can detect pi / 2-BPSK. At 220, gNB responds to UE 110 (which is a UE supporting pi / 2-BPSK) with Msg4 containing RRC connection establishment information.

[0055] Figure 2B Similar to Figure 2AHowever, in 212B, gNB 150 attempts to identify the transmission as pi / 2-BPSK based on DMRS, but the CRC check fails. Here, gNB first detects pi / 2-BPSK based on DMRS. If the detection has high confidence based on DMRS sequence correlation, but the CRC check fails for the received packet, a retransmission request is sent at 230. This retransmission request can be sent using a different Radio Network Temporary Identifier (RNTI). Thus, only pi / 2-BPSK UE 110 will receive the retransmission grant, thereby avoiding retransmission conflicts for another UE 210. For example, at 230, gNB can send an uplink grant allocation to UE 110 via the Physical Downlink Control Channel (PDCCH), which includes a downlink control information (DCI) format for retransmission using a new, different RNTI for pi / 2-BPSK. At 240, UE 110 can retransmit. Here, conflicts between UEs 110 and 210 during retransmission are avoided because UE 210 (using a different QPSK MCS) will verify the temporary C-RNTI used to receive additional DCI for retransmission. The other UE 210 (whose content is used for RACH access) will declare failure at 235 before receiving Msg4 and retry RACH access. For pi / 2-BPSK, UE conflicts from other UEs used for retransmission are avoided.

[0056] The network, including the base station, can indicate via system information that the set of MCSs reserved for pi / 2-BPSK should not be used by other UEs. When a UE that does not support pi / 2-BPSK receives this information, and when the uplink grant includes the set of MCSs allocated for pi / 2-BPSK, these UEs should avoid transmitting Msg3. This avoids conflicts between pi / 2-BPSK and other UEs using the same uplink grant. In this case, only legacy UEs that do not support the new parameters of the system information will attempt to use the MCS. Here, conflicts can be avoided by controlling other UEs not to use the selected MCS.

[0057] As described above, the network, including the base station, can also indicate and / or control the power boost of pi / 2-BPSK transmissions, with the power boost indication used for initial, retransmission, or RACH retry power boosts. Using this indication, the use of the pi / 2-BPSK power boost feature can also be controlled based on network interference conditions.

[0058] Figure 3A block diagram of a network node 300 according to some example embodiments is depicted. The network node 300 may be configured to provide one or more network-side functions, such as a base station. According to some example embodiments, the network node 300 may include a network interface 302, a processor 320, and a memory 304. The network interface 302 may include a radio transceiver to allow access to a servicing UE. These radio transceivers may be compatible and therefore similar to those described below for a UE. The network interface may also include wired and / or wireless interfaces to other nodes, including other base stations, the Internet, and / or other nodes and network functions. The memory 304 may include volatile and / or non-volatile memory containing program code that, when executed by at least one processor 320, provides in particular the procedures disclosed herein concerning a base station. In some embodiments, a network node may include or be included in a base station, the base station being configured to send information to a user equipment indicating network support for initial network access based on a pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; receive initial network access including a connection request from the user equipment via a physical uplink shared channel; and detect that the connection request is transmitted using pi / 2-BPSK modulation and coding.

[0059] Figure 4 A block diagram of an apparatus 10 according to some example embodiments is shown. The apparatus may include or be included in user equipment (e.g., user equipment 110, 210, etc.).

[0060] Device 10 may include at least one antenna 12 communicating with transmitter 14 and receiver 16. Alternatively, the transmitting antenna and receiving antenna may be separate. Device 10 may also include a processor 20 configured to provide signals to and receive signals from the transmitter and receiver, respectively, and to control the functions of the device. Processor 20 may be configured to control the functions of the transmitter and receiver via electrical leads to the transmitter and receiver. Similarly, processor 20 may be configured to control other elements of device 10 via electrical leads connecting processor 20 to other elements such as a display or memory. Processor 20 may be embodied in, for example, a variety of ways, including a circuit system, at least one processing core, one or more microprocessors having an accompanying digital signal processor(s), one or more processors without an accompanying digital signal processor(s), one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuit systems, one or more computers, various other processing elements, including integrated circuits (e.g., application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc.) or some combination thereof. Therefore, although in Figure 4The processor 20 is shown as a single processor, but in some example embodiments, the processor 20 may include multiple processors or processing cores.

[0061] Device 10 is capable of operating using one or more air interface standards, communication protocols, modulation types, access types, etc. Signals transmitted and received by processor 20 may include signaling information conforming to applicable cellular system air interface standards and / or any number of different wired or wireless network technologies (including but not limited to Wi-Fi, wireless local area network (WLAN) technologies such as IEEE 802.11, 802.16, 802.3, ADSL, DOCSIS, etc.). Furthermore, these signals may include voice data, user-generated data, user-requested data, etc.

[0062] For example, the device 10 and / or its cellular modem can operate according to various first-generation (1G) communication protocols, second-generation (2G or 2.5G) communication protocols, third-generation (3G) communication protocols, fourth-generation (4G) communication protocols, fifth-generation (5G) communication protocols, Internet Protocol Multimedia Subsystem (IMS) communication protocols (e.g., Session Initiation Protocol (SIP)), etc. For example, the device 10 can operate according to 2G wireless communication protocols such as IS-136, Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), IS-95, Code Division Multiple Access (CDMA), etc. Furthermore, for example, the device 10 can operate according to 2.5G wireless communication protocols such as General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), etc. Furthermore, for example, the device 10 can operate according to 3G wireless communication protocols such as Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA2000), Wideband Code Division Multiple Access (WCDMA), Time Division Synchronous Code Division Multiple Access (TD-SCDMA), etc. Additionally, device 10 can operate according to 3.9G wireless communication protocols (such as Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), etc.). Furthermore, for example, device 10 can operate according to 4G wireless communication protocols (such as Advanced LTE), 5G, and similar wireless communication protocols that may be developed subsequently.

[0063] It is understood that processor 20 may include circuitry for implementing the audio / video and logic functions of device 10. For example, processor 20 may include a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, etc. The control and signal processing functions of device 10 can be distributed among these devices according to their respective capabilities. Processor 20 may also include an internal voice encoder (VC) 20a, an internal data modem (DM) 20b, etc. Furthermore, processor 20 may include the ability to operate one or more software programs, which may be stored in memory. Typically, processor 20 and the stored software instructions can be configured to cause device 10 to perform actions. For example, processor 20 may be able to operate a connectivity program, such as a web browser. The connectivity program may allow device 10 to transmit and receive network content, such as location-based content, according to protocols such as Wireless Application Protocol (WAP), Hypertext Transfer Protocol (HTTP), etc.

[0064] Device 10 may also include a user interface, including, for example, headphones or speaker 24, ringer 22, microphone 26, display 28, user input interface, etc., which is operatively coupled to processor 20. As described above, display 28 may include a touch-sensitive display, where a user can touch and / or gesture to make selections, input values, etc. Processor 20 may also include a user interface circuitry configured to control at least some functions of one or more elements of the user interface (such as speaker 24, ringer 22, microphone 26, display 28, etc.). Processor 20 and / or the user interface circuitry including processor 20 may be configured to control one or more functions of one or more elements of the user interface via computer program instructions (e.g., software and / or firmware) stored in memory accessible to processor 20 (e.g., volatile memory 40, non-volatile memory 42, etc.). Device 10 may include a battery for powering various circuits associated with the mobile terminal (e.g., circuitry for providing mechanical vibration as a detectable output). The user input interface may include devices that allow device 20 to receive data, such as keypad 30 (which may be a virtual keyboard displayed on display 28 or an externally coupled keyboard) and / or other input devices.

[0065] like Figure 4 As shown, device 10 may also include one or more mechanisms for sharing and / or acquiring data. For example, device 10 may include a short-range radio frequency (RF) transceiver and / or interrogator 64, so that data can be shared with and / or acquired from electronic devices according to RF technology. Device 10 may include other short-range transceivers, such as infrared (IR) transceiver 66, using Bluetooth... TM Bluetooth that operates using wireless technologyTM (BT) transceiver 68, Wireless Universal Serial Bus (USB) transceiver 70, Bluetooth TM Low-power transceivers, ZigBee transceivers, ANT transceivers, cellular device-to-device transceivers, wireless LAN transceivers, and / or any other short-range radio technologies. Device 10, and particularly short-range transceivers, can be capable of transmitting and / or receiving data from electronic devices in the vicinity of the device (e.g., within 10 meters). Device 10, including Wi-Fi or wireless LAN modems, can also be capable of transmitting and / or receiving data from electronic devices according to various wireless networking technologies, including 6LoWpan, Wi-Fi, Wi-Fi Low Power, WLAN technologies such as IEEE 802.11, IEEE 802.15, IEEE 802.6, etc.

[0066] Device 10 may include memory such as a Subscriber Identity Module (SIM) 38, a Removable Subscriber Identity Module (R-UIM), an eUICC, a UICC, etc., which may store information elements related to mobile subscribers. In addition to the SIM, device 10 may also include other removable and / or fixed memory. Device 10 may include volatile memory 40 and / or non-volatile memory 42. For example, volatile memory 40 may include random access memory (RAM) (including dynamic and / or static RAM), on-chip or off-chip cache memory, etc. Non-volatile memory 42, which may be embedded and / or removable, may include, for example, read-only memory, flash memory, magnetic storage devices (e.g., hard disks, floppy disk drives, magnetic tapes), optical disk drives and / or media, non-volatile random access memory (NVRAM), etc. Like volatile memory 40, non-volatile memory 42 may include cache areas for temporary data storage. At least a portion of the volatile and / or non-volatile memory may be embedded in processor 20. The memory can store one or more software programs, instructions, information fragments, data, etc., which can be used by the device to perform the operations concerning the UE disclosed herein.

[0067] The memory may include an identifier capable of uniquely identifying device 10, such as an International Mobile Equipment Identity (IMEI). In an example embodiment, processor 20 may be configured using computer code stored in memory 40 and / or 42 to provide the operation of the UE disclosed herein.

[0068] Some embodiments disclosed herein can be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. For example, the software, application logic, and / or hardware may reside on memory 40, control device 20, or electronic components. In some example embodiments, the application logic, software, or instruction set is maintained on any of a variety of conventional computer-readable media. In the context of this document, "computer-readable medium" can be any non-transitory medium that can contain, store, transmit, propagate, or transfer instructions for use by or in conjunction with an instruction execution system, apparatus, or device (such as a computer or data processor circuit system), such as... Figure 4 The example shown may include a non-transitory computer-readable storage medium, which may be any medium that can contain or store instructions for use by or in conjunction with an instruction execution system, apparatus, or device, such as a computer.

[0069] In some embodiments, the apparatus may include or be included in a user equipment configured to provide, at least in some example embodiments, a method comprising receiving information indicating network support for initial network access based on a pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; and, in response to the received system information, performing initial network access by at least sending a connection request based on the pi / 2-BPSK modulation and coding scheme.

[0070] Without limiting the scope, interpretation, or application of the claims that appear below in any way, the technical effects of one or more example embodiments disclosed herein may include enhanced initial network access for the UE.

[0071] Depending on the desired configuration, the subjects described herein can be embodied in systems, apparatuses, methods, and / or articles. For example, the base stations and user equipment (or one or more components thereof) and / or processes described herein can be implemented using one or more of the following: a processor executing program code, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), an embedded processor, a field-programmable gate array (FPGA), and / or combinations thereof. These various implementations can include implementations in one or more computer programs executable and / or interpretable on a programmable system including at least one programmable processor (which may be dedicated or general-purpose) that can be coupled to receive and transmit data and instructions from and to a storage system, at least one input device, and at least one output device. These computer programs (also referred to as programs, software, software applications, applications, components, program code, or code) include machine instructions for the programmable processor and can be implemented in high-level programming and / or object-oriented programming languages ​​and / or in assembly / machine language. As used herein, the term "computer-readable medium" means any computer program product, machine-readable medium, computer-readable storage medium, apparatus, and / or device (e.g., magnetic disk, optical disk, memory, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, including machine-readable media that receive machine instructions. Similarly, systems that may include a processor and memory coupled to the processor are also described herein. Memory may include one or more programs that cause the processor to perform one or more operations described herein.

[0072] While some variations have been described in detail above, other modifications or additions are possible. In particular, other features and / or variations may be provided in addition to those set forth herein. Furthermore, the above implementations can be implemented for various combinations and sub-combinations of the disclosed features, and / or combinations and sub-combinations of several other features disclosed above. Other embodiments are within the scope of the following claims.

[0073] If desired, the different functions discussed herein may be performed in different orders and / or simultaneously with each other. Furthermore, one or more of the aforementioned functions may be optional or may be combined, if desired. Although various aspects of some embodiments are set forth in the independent claims, other aspects of some embodiments include other combinations of features from the described embodiments and / or dependent claims with features of the independent claims, not just those expressly set forth in the claims. It should also be noted herein that although exemplary embodiments have been described above, these descriptions should not be regarded in a limiting sense. Rather, several variations and modifications may be made without departing from the scope of some embodiments as defined in the appended claims. Other embodiments may fall within the scope of the following claims. The term “based on” includes “at least based on”. Unless otherwise stated, the use of phrases such as “such as” means “such as, for example”.

Claims

1. A device for communication, comprising: At least one processor; as well as At least one memory including computer program code, said at least one memory and said computer program code being configured together with said at least one processor such that the means at least: Receive information indicating network support for initial network access based on the pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; as well as In response to the received system information, the initial network access is performed by sending at least a connection request based on the pi / 2-BPSK modulation and coding scheme. The received information also indicates one or more of the following: whether the power boost is used to perform random access channel access using the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal; whether the power boost is used for the initial network access or retransmission; and whether the power boost is used for hybrid automatic repeat request retransmission.

2. The apparatus of claim 1, wherein the information is received as transmitted system information before the Physical Random Access Channel (PRACH) preamble is sent by the user equipment.

3. The apparatus of claim 1, wherein the information is received from the network as a random access response including uplink authorization from the base station.

4. The apparatus of claim 1, wherein the received information further indicates network support for the pi / 2-BPSK demodulation reference signal.

5. The apparatus of claim 1, wherein the connection request comprises a radio resource control connection request message transmitted via a physical uplink shared channel based on the pi / 2-BPSK modulation and coding scheme and a demodulation reference signal.

6. The apparatus of claim 5, wherein the demodulation reference signal comprises a pi / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal.

7. The apparatus of claim 1, wherein the apparatus is further configured to at least transmit a Physical Random Access Channel (PRACH) preamble indicating that the user equipment supports the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal.

8. The apparatus according to any one of claims 1 to 7, wherein the received information further indicates one or more modulation and coding scheme indices suitable for pi / 2BPSK transmission.

9. A device for communication, comprising: At least one processor; as well as At least one memory including computer program code, said at least one memory and said computer program code being configured together with said at least one processor such that the means at least: Send information to the user equipment indicating network support for initial network access based on the pi / 2 binary phase shift keying (pi / 2-BPSK) modulation and coding scheme; The initial network access is received via the physical uplink shared channel, including a connection request from the user equipment. as well as The connection request was detected as being transmitted using the pi / 2-BPSK modulation and encoding. The transmitted information also indicates one or more of the following: whether the power boost is used to perform random access channel access using the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal; whether the power boost is used for the initial network access or retransmission; and whether the power boost is used for hybrid automatic repeat request retransmission.

10. The apparatus of claim 9, wherein the apparatus is further configured to respond to the connection request with connection establishment information, at least in response to the detection.

11. The apparatus of claim 9, wherein the information is transmitted as at least one of: system information transmitted before the Physical Random Access Channel (PRACH) preamble is transmitted by the user equipment, or a random access response including uplink grant from the base station.

12. The apparatus of claim 9, wherein the connection request comprises a radio resource control connection request message carried via a physical uplink shared channel using the pi / 2-BPSK modulation and coding scheme and a demodulation reference signal.

13. The apparatus of claim 12, wherein the demodulation reference signal comprises a pi / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal sequence.

14. The apparatus of claim 9, wherein the information indicating network support further indicates support for the pi / 2-BPSK demodulation reference signal.

15. The apparatus of claim 9, wherein the apparatus is further configured to receive at least a Physical Random Access Channel (PRACH) preamble indicating that the user equipment supports the pi / 2-BPSK modulation and coding scheme and / or the pi / 2-BPSK demodulation reference signal.

16. The apparatus according to any one of claims 9 to 15, wherein the transmitted information further indicates one or more modulation and coding scheme indices suitable for pi / 2 BPSK transmission.

17. The apparatus according to any one of claims 9 to 10, wherein the detection further comprises detecting that the connection request is transmitted using the pi / 2-BPSK modulation and coding scheme based on at least one of the correlation of the demodulated reference signal sequence indicating the pi / 2-BPSK modulation and coding scheme, or the cyclic redundancy check of the demodulated reference signal sequence.

18. The apparatus of claim 17, wherein in response to the failure of the cyclic redundancy check, an uplink grant is assigned to the user equipment, the uplink grant including a downlink control information format for retransmission using a new radio network temporary identifier for pi / 2-BPSK-based retransmission.

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