π / 2-BPSK for initial access

Abstract

To provide methods and apparatus, including computer program products, for π / 2-BPSK initial access.SOLUTION: In some example embodiments, there may be provided a method that includes: receiving, at user equipment, information indicating network support of an initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; and performing, in response to the received system information, the initial network access by at least sending a connection request based on the π / 2-BPSK modulation and coding scheme. Related systems, methods, and articles of manufacture are also described.SELECTED DRAWING: Figure 1B

Description

Technical Field

[0001] The subject matter described herein relates to cellular systems, and more particularly, to initial access.

Background Art

[0002] In 3GPP, New Radio (NR) provides π / 2 Binary Phase Shift Keying (π / 2-BPSK) in the uplink path as the lowest order (e.g., having the fewest bits per symbol) of a set of digital modulations for uplink (UL) data transmission. π / 2-BPSK can be generated from a standard BPSK signal by multiplying a symbol sequence by a rotating phase vector with a phase increment of π / 2 per symbol period. This π / 2-BPSK can have the same bit error rate performance as BPSK on a linear channel, while the envelope fluctuation may be reduced.

Summary of the Invention

[0003] Methods and apparatuses (including computer program products) related to π / 2-BPSK initial access are provided.

[0004] In some exemplary embodiments, a method may be provided that includes, in a user equipment, receiving information indicating network support for initial network access based on a π / 2 Binary Phase Shift (π / 2-BPSK) modulation and coding scheme, and performing initial network access by transmitting a connection request based at least on the received system information and based on the π / 2-BPSK modulation and coding scheme.

[0005] In some variations, one or more of the features disclosed in this specification, including the following features, may be optionally included in any feasible combination as an optional selection. The information may be received as system information transmitted before a physical random access channel (PRACH) preamble is transmitted by a user equipment. The information may be received from a network as a random access response including an uplink grant from a base station. The received information may further indicate network support for a π / 2-BPSK demodulation reference signal. The connection request may include a radio resource control connection request message transmitted via a physical uplink shared channel based on a π / 2-BPSK modulation and coding scheme and a demodulation reference signal. The demodulation reference signal may include a π / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal. A physical random access channel (PRACH) preamble indicating user equipment support for a π / 2-BPSK modulation and coding scheme and / or a π / 2-BPSK demodulation reference signal may be transmitted. The received information may further indicate whether a power boost is used for executing random access channel access using a π / 2-BPSK modulation and coding scheme and / or a π / 2-BPSK demodulation reference signal, whether a power boost is used for initial network access or retransmission, whether a power boost is used for hybrid automatic repeat request retransmission, or one or more of one or more modulation and coding scheme indexes suitable for π / 2-BPSK transmission.

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

[0007] In some variations, one or more of the features disclosed in this specification, including the following features, may be optionally selected and included in any feasible combination. The connection request may be configured to be responded to with connection setup information in response to detection. The information may be transmitted as at least one of system information transmitted before a physical random access channel (PRACH) preamble is transmitted by a user equipment or a random access response including an uplink grant from a base station. The connection request may include a radio resource control connection request message carried via a physical uplink shared channel by using a π / 2-BPSK modulation and coding scheme and a demodulation reference signal. The demodulation reference signal may include a π / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal sequence. The information indicating network support may further indicate support for a π / 2-BPSK demodulation reference signal. A physical random access channel (PRACH) preamble indicating user equipment support for a π / 2-BPSK modulation and coding scheme and / or a π / 2-BPSK demodulation reference signal may be received. The information to be transmitted may further indicate whether a power boost is used for execution of random access channel access using a π / 2-BPSK modulation and coding scheme and / or a π / 2-BPSK demodulation reference signal, whether a power boost is used for initial network access or retransmission, whether a power boost is used for hybrid automatic repeat request retransmission, or one or more of one or more modulation and coding scheme indexes suitable for π / 2-BPSK transmission. The detection may further include detecting that the connection request is transmitted using a π / 2-BPSK modulation and coding scheme based on at least one of a demodulation reference signal sequence indicating a π / 2-BPSK modulation and coding scheme or a cyclic redundancy check of a demodulation reference signal sequence. In response to a failure of the cyclic redundancy check, an uplink grant allocation including a downlink control information format for retransmission using a new radio network temporary identifier for π / 2-BPSK based retransmission may be transmitted to the user equipment.

[0008] The above aspects and features may be implemented in a system, apparatus, method, and / or article according to a desired configuration. Details of one or more variations of the subject matter described herein are set forth in the accompanying drawings and the following description. The features and advantages of the subject matter described herein will become apparent from the following description, the drawings, and the claims.

Brief Description of the Drawings

[0009]

Figure 1A

Figure 1B

Figure 1C

Figure 2A

Figure 2B

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] In the drawings, the same label is used to represent the same or similar items.

[0011] As described above, the NR system (also referred to as the 5G system) provides support for the π / 2-BPSK modulation and coding scheme (MCS). However, since the π / 2-BPSK MCS is an optional feature of the user equipment (UE), not all UEs can select to support π / 2-BPSK. Optionally, when using this π / 2-BPSK MCS, the UE can support spectrum shaping to improve the peak-to-average power ratio (PAPR) performance, correspondingly reducing the maximum power reduction (MPR) value while increasing the average transmission power level. Furthermore, when using π / 2-BPSK, the UE can also support a nominal 3 dB power boost (a reference power of 26 dBm instead of the normal 23 dBm for UEs in power class 3 as shown in Note 1 of Table 1 below). In such a case, the requirements for spectrum flatness are somewhat relaxed and the maximum power reduction value becomes somewhat larger. As a result, the actual power difference in the internal resource block (RB) can be reduced to approximately 2.8 dB, while there is no power difference at the band edge. The following Table 1 (quoted from 3GPP TS38.101-1) shows the MPR for power class 3 of π / 2-BPSK by comparison with other modulation and coding schemes.

[0012] Table 1

Table 1

[0013] By using π / 2-BPSK and power boosting, the uplink coverage of the UE can be further improved, for example, than the four-phase shift (QPSK), which is the minimum 3GPP mandatory (i.e., not an optional feature) modulation order in the uplink. This improvement related to π / 2-BPSK can easily perform modulation with more accurate demodulation (even though the bit rate per symbol is halved in π / 2-BPSK compared to QPSK), which is considered to be due to the increase in transmission power. Using π / 2-BPSK and power boosting to enhance uplink coverage can be particularly useful for the UE in a large cell deployment at the edge of the cell (such as a large cell deployment in rural areas).

[0014] In 3GPP Release-15 (Rel-15), the demodulation reference signal (DMRS) symbols (generated based on the Zadoff-Chu sequence) are considered to have inferior peak-to-average power ratio performance compared to the π / 2-BPSK modulated data symbols. As a result, on average, the maximum power reduction is greater than that required for data symbols, and the achievable transmission power may be reduced. In 3GPP Release-16 (Rel-16), π / 2-BPSK modulated DMRS can be used in the physical uplink shared channel (PUSCH) with π / 2-BPSK modulation. Since this new DMRS design is a pseudo-random sequence modulated by π / 2-BPSK, the peak-to-average power ratio performance can be similar to that of data symbols. Therefore, an overall performance improvement for the MPR requirement can be achieved. For example, the π / 2-BPSK DMRS can provide an improvement in MPR of 2 - 3 dB (e.g., a smaller MPR) compared to the Rel-15 DMRS.

[0015] The initial access procedure of the UE to the network (also referred to as the random access channel (i.e., RACH) procedure) is used, for example, for connection setup. Figure 1A shows an example of the RACH procedure for the initial access by the UE110 to a network including a base station (e.g., a 5G gNB type base station 150).

[0016] Regarding UE110, in the initial network access procedure, in the physical uplink shared channel (PUSCH), a first uplink message (Msg3 (radio resource control (RRC) connection request)) transmission (106) follows a random access channel (RACH) transmission (e.g., refer to Msg1 (physical random access channel (PRACH) preamble) in 102). This uplink transmission on the PUSCH is scheduled by an uplink grant (104) provided in a random access response message (Msg2) provided by a network such as base station 150. The Msg2 uplink grant (provided for initial access) includes a modulation and coding scheme (MCS) for UE's Msg3 transmission and a PUSCH resource region. Also, the base station may respond with a fourth message Msg4 with an RRC connection setup including a contention resolution identifier at 108. However, in the procedure of FIG. 1A, it is considered that the UE's initial access transmission in Msg3 cannot be π / 2-BPSK. This is because π / 2-BPSK is an optional UE capability and the network or base station cannot recognize whether the UE can use this function during initial access.

[0017] In some exemplary embodiments, a method for indicating π / 2-BPSK PUSCH support is provided prior to initial access in Msg3.

[0018] In some exemplary embodiments, π / 2-BPSK DMRS for PUSCH transmission during UE's initial access, such as an RRC connection request of Msg3 to the network, is provided.

[0019] In some exemplary embodiments, by using network signaling, the UE may be enabled to use the π / 2-BPSK modulation and coding scheme for Msg3 transmission on the PUSCH and / or the π / 2-BPSK modulation for the DMRS sequence also transmitted on the PUSCH. As described above, by using the π / 2-BPSK MCS for Msg3 transmission and / or the π / 2-BPSK DMRS, it is possible to improve the coverage performance of the UE's initial access procedure, for example, in the case of cell-edge UEs in large cell deployments.

[0020] By using the π / 2-BPSK DMRS sequence, the DMRS sequence in the case of π / 2-BPSK can be detected because it is different from other modulation and coding schemes. In other words, the sequence (e.g., code) used for π / 2-BPSK DMRS is a different sequence when compared with the code used for QPSK DMRS. For this reason, a network such as a network node (e.g., a base station) can detect the DMRS sequence in the case of π / 2-BPSK. Also, the network node may be configured to distinguish the type of transmission based on two different DMRS sequences of the same type, such as between two different π / 2-BPSK DMRS sequences or between two different Zadoff-Chu (ZC) DMRS sequences.

[0021] In some exemplary embodiments, a network, particularly a base station, may detect the difference between π / 2-BPSK MCS transmission and QPSK MCS transmission based on the correlation of received DMRS for two types of DMRS. For example, the base station may detect which of the two DMRS sequences is present by correlating the sequence of π / 2-BPSK DMRS used in a certain MCS that uses π / 2-BPSK modulation for data transmission on PUSCH and the sequence of ZC DMRS used in another MCS that uses QPSK modulation for data transmission, thereby determining which of the two MCSs (e.g., π / 2-BPSK or QPSK) is used for data transmission on PUSCH. As an alternative or in addition, the base station may detect a demodulation attempt by first assuming one of the two transmission modes of DMRS and PUSCH, and if the PUSCH CRC fails, assume that the UE used the other transmission mode and retry.

[0022] FIG. 1B shows an example of an initial network access process in a UE according to some exemplary embodiments. Refer also to FIG. 1A in the description of FIG. 1B.

[0023] At 120, the UE 110 may be configured to receive information indicating that the network supports initial UE access based on π / 2-BPSK MCS and π / 2-BPSK DMRS. For example, the UE may receive from the base station 150 information indicating that (1) initial access such as Msg3 transmitted by PUSCH at 106 can be set by a π / 2-BPSK modulation and coding scheme, and / or (2) a pseudo-random π / 2-BPSK modulated bit sequence can be used as the DMRS sequence for Msg3 PUSCH demodulation. For example, while the PUSCH data symbols are π / 2-BPSK modulated, the DMRS sequence may be a specific type indicating π / 2-BPSK. For example, the DMRS may be a pseudo-random bit sequence indicating π / 2-BPSK, or it may be a ZC sequence (however, in either case, the sequence indicates π / 2-BPSK rather than QPSK). As described above, the base station receiver uses the (known) DMRS sequence to estimate the UE's radio channel and demodulate the PUSCH data symbols.

[0024] The above information indicating network support for π / 2-BPSK (which may be received at 120) may be transmitted to the UE in various ways.

[0025] In some embodiments, the information indicating support for π / 2-BPSK may be a broadcast channel to the UE as part of the system information sent to the UE prior to the transmission of Msg1. For example, the base station may transmit system information indicating support for π / 2-BPSK as a downlink broadcast before the Msg1 preamble is transmitted at 102.

[0026] In some embodiments, the information indicating support for π / 2-BPSK may be transmitted by the RAR of Msg2 at 104. For example, the network may include information indicating network support for π / 2-BPSK in the RAR (e.g., Msg2), and by more dynamically controlling π / 2 access, for example, the UE may be allowed to proceed with initial access in Msg3 (when it supports π / 2-BPSK). When the RAR is used to carry the π / 2-BPSK indication, the system information broadcast (transmitted prior to the transmission of Msg1) may similarly include a π / 2-BPSK support indication.

[0027] Furthermore, the random access response 104 from the base station 150 may include an indication that the network supports initial UE access based on the π / 2-BPSK MCS and / or π / 2-BPSK DMRS. This indication may be in the form of an uplink grant (provided in Msg2) indicating that the π / 2-BPSK MCS and / or π / 2-BPSK DMRS can be used for the UE's initial access in Msg3.

[0028] Also, in some exemplary embodiments, the gNB 150 may indicate to the UE the range of initial MCS values applicable to π / 2-BPSK transmission. For example, the information received by the UE 110 at 120 may indicate a list of MCS values (or indices of these values) applicable to π / 2-BPSK MCS transmission. This may be in the form of MCS indices, an example of which is shown in Tables 3 and 4 below.

[0029] At 125, the UE may perform initial network access to the network by using π / 2-BPSK MCS and / or π / 2-BPSK DMRS. In response to receiving an uplink grant as described in 120, the UE may perform initial access by transmitting, via the PUSCH, an RRC connection request (e.g., Msg3 with π / 2-BPSK MCS) and π / 2-BPSK DMRS to the base station 150.

[0030] Figure 1C shows an example of an initial network access process at a base station according to some exemplary embodiments. Refer also to Figure 1A in the description of Figure 1B.

[0031] At 130, a network such as the base station 150 may transmit to the UE110 information including an indication that the network supports initial UE access based on π / 2-BPSK MCS and π / 2-BPSK DMRS. As described above, the base station 150 may transmit this indication in various ways, such as system information sent to the UE prior to transmitting Msg1 and / or the RAR of Msg2 in 104. In some exemplary embodiments, the information transmitted at 130 may indicate a list of applicable MCS values for π / 2-BPSK MCS transmission. This may be in the form of an MCS index, an example of which is shown in Tables 3 and 4 below.

[0032] At 135, the base station 150 may receive an initial access message transmitted from the UE110 using π / 2-BPSK MCS and / or π / 2-BPSK DMRS. For example, the base station 150 may receive Msg3 transmitted using π / 2-BPSK MCS and π / 2-BPSK DMRS via the PUSCH. Since the π / 2-BPSK DMRS can be detected as different from the QPSK DMRS, the base station 150 may detect that the UE has used π / 2-BPSK.

[0033] In some exemplary embodiments, a UE that supports π / 2-BPSK and π / 2-BPSK DMRS may transmit Msg3 using π / 2-BPSK if the uplink grant provided in a random access response (e.g., RAR in Msg2) indicates a specific MCS (e.g., an MCS reserved or designated for this purpose). Also, the RAR (including the uplink grant for the UE to transmit Msg3) includes the MCS that the UE uses. For example, the UE may use the MCS as π / 2-BPSK when a subset of the MCSs (specifiable by system information) is transmitted in the uplink grant.

[0034] Also, with possible support for π / 2-BPSK transmission for initial access, the UE may, if necessary, use power boost transmission for the initial access. The power boost operation for initial access may avoid the autonomous increase in the UE transmission power for initial access that may result in an increase in inter-cell interference, by control and setting by the network. As described above, the base station 150 may transmit this power boost indication in various ways, such as by system information transmitted to the UE via the RAR of Msg2 in 104, etc.

[0035] Regarding enabling power boosting for π / 2-BPSK transmission for initial access, the network may send an indication to the UE as to whether the UE can use power-boosted transmission for RACH access. As an alternative or addition to this, the network may send an indication to the UE that the UE can consider power boosting only for RACH retransmission rather than for initial transmission. As an alternative or addition to this, the network may send an indication to the UE as to whether high-power hybrid automatic repeat request (HARQ) retransmission can be transmitted on the PUSCH using power boosting. As an alternative or addition to this, the network may send an indication of an MCS index suitable for π / 2-BPSK transmission to the UE. As described above, the base station 150 may send this power-boost indication in various ways, such as by means of system information transmitted to the UE via the RAR of Msg2 in 104, etc. As described above, these indications may be provided to the UE by the network or the base station in various ways, such as by providing to the UE by means of a random access response (e.g., Msg2 in 104), inclusion in the system information sent to the UE prior to Msg1, and conveyance by means of a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), or other types of downlink, etc.

[0036] Referring again to FIG. 1A, the uplink grant information included in the random access response (RAR) of Msg2 may include one or more of the fields shown in Table 2 below (quoted from 3GPP TS38.213). Referring to Table 2, 4 bits are reserved for the designation of the MCS used for Msg3.

[0037] Table 2: Random Access Response Grant Content Field Sizes [TS38.213]

Table 2

[0038] According to some exemplary embodiments, if a PRACH preamble is used to detect the UE's ability to use π / 2 - BPSK, the currently reserved MCS values (see Tables 3 and 4 below cited from TS38.214) may be used for scheduling π / 2 - BPSK. If a UE capable of using π / 2 - BPSK uses a separate preamble, the network will be able to determine the π / 2 - BPSK ability based on the preamble itself. In this case, when the highlighted entry of the MCS index is transmitted in Msg2, the UE is capable of using π / 2 - BPSK. Here, the UE does not need to signal its ability. By transmitting the preamble (reserved for this type of π / 2 - BPSK UE), it indicates to the network that the UE is capable of using the π / 2 - BPSK MCS. Depending on the type of UE determined by the type of DMRS in Msg3, a set of MCS minimum values may allow the UE to be permitted an uplink access grant for QPSK transmission or π / 2 - BPSK transmission at 104 (regardless of the presence or absence of power boost). When tp - π / 2 - BPSK is set, q = 1 (e.g., when π / 2 - BPSK is used), otherwise q = 2 (e.g., when QPSK is used), and the default values in Table 3 are used to determine the modulation order and code rate when the MCS index is 0 or 1. For other MCS indices, the operation may remain unchanged. Also, the network may set the use of the other MCS table for lower data rates (and larger coverage), and may use π / 2 - BPSK with the lowest six MCSs. Further, the network may set the MCS suitable for π / 2 - BPSK in the system information.

[0039] Table 3: Table 6.1.4.1 - 1: MCS Index Table for PUSCH with Transform Precoding and 64QAM [Table 6.1.4.1 - 1 of TS38.214]

Table 3

[0040] Table 4: Conversion precoding and MCS index table for PUSCH of 64QAM [Table 6.1.4.1-2 of TS38.214]

Table 4

[0041] Figure 2A shows an example of initial network access where one of the UEs 110 supports π / 2-BPSK MCS and π / 2-BPSK DMRS for PUSCH (e.g., can be configured with these), while another UE 210 does not support π / 2-BPSK MCS and π / 2-BPSK DMRS. Since there may be another UE 210 that can receive the same uplink grant as UE 110 on the PUSCH for contention-based RACH access, the gNB 150 may, at 106, (1) receive Msg3 106 from π / 2-BPSK UE 110 sent with π / 2-BPSK MCS including π / 2-BPSK DMRS, and at 206, (2) receive another Msg3 from UE 210 using QPSK (corresponding to the actual MCS index interpretation of the MCS table). For example, since both π / 2-BPSK and QPSK share the same index, UE 110 may receive an uplink grant including MCS index 0 (see, e.g., Table 3), and UE 210 may receive an uplink grant including MCS index 0 (see, e.g., Table 3). However, (UE 110 which supports π / 2-BPSK) transmits Msg3 based on MCS index 0 as π / 2-BPSK MCS, while (UE 210 which uses QPSK instead of supporting π / 2-BPSK) transmits Msg3 based on MCS index 0 as QPSK MCS. Since the MCS index is shared, the base station may need to detect whether the UE is using π / 2-BPSK or not.

[0042] In 212A, gNB150 can enable the identification of MCS as π / 2-BPSK in 214 by clearly distinguishing QPSK and π / 2-BPSK based on the received DMRS and / or CRC check (for example, decoding using different MCSs). For example, the gNB may (1) perform the correlation of the received DMRS for two types of DMRS in the cases of π / 2-BPSK and QPSK, or (2) after attempting demodulation assuming one of the two transmission modes, if the PUSCH CRC fails, the UE may be assumed to have used the other transmission mode and retried. In this way, the gNB can detect π / 2-BPSK. In 220, the gNB responds with Msg4 including the RRC connection setup information to UE110 (the UE corresponding to π / 2-BPSK).

[0043] Figure 2B is similar to Figure 2A, but in 212B, gNB150 attempts to identify that the transmission based on DMRS is π / 2 - BPSK, but the CRC check fails. Here, the gNB first detects π / 2 - BPSK based on DMRS. Even if this detection is highly reliable based on DMRS sequence correlation, if the CRC check of the received packet fails, at 230, a retransmission request will be sent. This retransmission request can be sent using a different Radio Network Temporary Identifier (RNTI). As a result, only the π / 2 - BPSK UE110 will receive the retransmission grant, thus avoiding the collision of the other UE210 in the case of retransmission. For example, at 230, the gNB may send the allocation of uplink grant including the downlink control information (DCI) format for retransmission using a new different RNTI for π / 2 - BPSK to UE110 via the Physical Downlink Control Channel (PDCCH). UE110 can retransmit at 240. Here, the collision between UE110 and 210 in retransmission is avoided because the other UE210 (using the other QPSK MCS) will confirm the temporary C - RNTI to receive another DCI for retransmission. The other UE210 (satisfying the RACH access) declares failure at 235 before receiving Msg4 and retries the RACH access. In the case of π / 2 - BPSK, retransmission is performed while avoiding UE collision with other UEs.

[0044] A network including a base station may indicate by system information that an MCS set reserved for π / 2-BPSK should not be used by other UEs. When a UE that does not support π / 2-BPSK receives this information, if the uplink grant includes the MCS set allocated for π / 2-BPSK, these UEs shall avoid transmitting Msg3. This avoids collisions where both π / 2-BPSK UEs and other UEs use 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, collisions can be avoided by controlling the selected MCS so that other UEs do not use it.

[0045] Also, as described above, a network including a base station may indicate the use of power boost for initial access, retransmission, or RACH reattempt by means of an indication and / or control of power boost for π / 2-BPSK transmission. This indication enables the control of the use of the power boost function of π / 2-BPSK according to the interference situation of the network.

[0046] FIG. 3 is a block diagram of a network node 300 according to some exemplary embodiments. The network node 300 may be configured to provide one or more network-side functions such as a base station. According to some exemplary 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 that enables access to a served UE. These radio transceivers may be compatible with and similar to the radio transceivers described below with respect to the UE. Also, the network interface may include a wired and / or wireless interface to other base stations, the Internet, and / or other nodes and other nodes including other network functions. The memory 304 may include volatile and / or non-volatile memory that includes program code that, when executed by at least one processor 320, provides the processes disclosed herein, among other things, with respect to the base station. In some embodiments, the network node may transmit to the user equipment information indicating network support for initial network access based on a π / 2 binary phase shift (π / 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 was transmitted using the π / 2-BPSK modulation and coding scheme, and may include a base station configured to perform the above or be included in the base station.

[0047] FIG. 4 is a block diagram of an apparatus 10 according to some exemplary embodiments. The apparatus may include a user equipment such as user equipment 110, 210, etc., or may be included in the user equipment.

[0048] Device 10 may include at least one antenna 12 in communication with a transmitter 14 and a receiver 16. Alternatively, the transmitting antenna and the receiving antenna may be separate. Also, device 10 may include a processor 20 configured to supply signals to the transmitter and receive signals from the receiver, respectively, and to control the functions of the device. Processor 20 may be configured to control the functions of the transceiver by the action of control signaling via conductors to the transmitter and receiver. Similarly, processor 20 may be configured to control other elements of device 10 by the action of control signaling via conductors connecting the processor 20 to other elements such as a display or a memory. Processor 20 may be embodied in various ways, such as, for example, a circuit, at least one processing core, one or more microprocessors accompanied by a digital signal processor, one or more processors not accompanied by a digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, a processing circuit, one or more computers, an integrated circuit (e.g., an application specific integrated circuit (ASIC), a field programmable gate array (FPGA)), or some combination thereof, etc. Thus, although shown as a single processor in FIG. 4, in some exemplary embodiments, processor 20 may include multiple processors or processing cores.

[0049] Device 10 may be operable by one or more air interface standards, communication protocols, modulation types, access types, and / or the like. Signals transmitted and received by processor 20 may include air interface standards of an applicable cellular system and / or signaling information related to any number of different wired or wireless networking technologies (including, but not limited to, wireless local area network (WLAN) technologies such as Wi-Fi, Institute of Electrical and Electronics Engineers (IEEE) 802.11, 802.16, 802.3, etc., ADSL, DOCSIS, and / or the like). These signals may also include speech data, user-generated data, user-request data, and / or the like.

[0050] For example, device 10 and / or its cellular modem may be operable 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)), and / or the like. For example, device 10 may be operable 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), and / or the like. Also, for example, device 10 may be operable according to 2.5G wireless communication protocols such as General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), and / or the like. Further, for example, device 10 may be operable 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), and / or the like. Also, device 10 may be operable according to 3.9G wireless communication protocols such as Long Term Evolution (LTE), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and the like. Also, for example, device 10 may be operable according to 4G wireless communication protocols such as LTE-Advanced, 5G, and / or the like, as well as similar wireless communication protocols that may be developed in the future.

[0051] It is understood that the processor 20 may include a circuit for realizing the voice / video and logical functions of the apparatus 10. For example, the processor 20 may include a digital signal processor device, a microprocessor device, an analog-to-digital converter, a digital-to-analog converter, and / or the like. The control and signal processing functions of the apparatus 10 may be assigned to these devices according to their respective capabilities. Also, the processor 20 may include an internal vocoder (VC) 20a, an internal data modem (DM) 20b, and / or the like. Further, the processor 20 may include a function of operating one or more software programs storable in a memory. Generally, the processor 20 and the stored software instructions may be configured to cause the apparatus 10 to execute operations. For example, the processor 20 may be capable of operating a connection program such as a web browser. According to the connection program, the apparatus 10 may be able to transmit and receive web content such as location-based content according to protocols such as the Wireless Application Protocol (WAP), the Hypertext Transfer Protocol (HTTP), and / or the like.

[0052] In addition, the apparatus 10 may include a user interface such as, for example, an earphone or a speaker 24, a ringer 22, a microphone 26, a display 28, a user input interface, and / or the like, which may be operably coupled to the processor 20. As described above, the display 28 may include a touch display, and the user may perform selections, value inputs, and / or similar operations by touch and / or gestures. Also, the processor 20 may include a user interface circuit configured to control at least some functions of one or more elements of the user interface such as the speaker 24, the ringer 22, the microphone 26, the display 28, and / or the like. The processor 20 and / or the user interface circuit including the processor 20 may be configured to control one or more functions of one or more elements of the user interface by computer program instructions (such as software and / or firmware) stored in a memory accessible to the processor 20 (such as volatile memory 40, non-volatile memory 42, and / or the like). The apparatus 10 may include a battery that powers various circuits associated with the mobile terminal (such as a circuit that provides a mechanical vibration as a detectable output). The user input interface may include a keypad 30 (a virtual keyboard presented on the display 28 or an externally coupled keyboard is possible) and / or other input devices, and / or devices that enable the reception of data by the apparatus 20.

[0053] Also, as shown in FIG. 4, the apparatus 10 may include one or more mechanisms for data sharing and / or acquisition. For example, the apparatus 10 may include a short-range radio frequency (RF) transceiver and / or interrogator 64, and may be configured to share data with and / or acquire data from an electronic device according to RF technology. The apparatus 10 may include an infrared (IR) transceiver 66, a Bluetooth® (BT) transceiver 68 operating using Bluetooth® wireless technology, a wireless universal serial bus (USB) transceiver 70, a Bluetooth® low energy transceiver, a ZigBee® transceiver, an ANT transceiver, a cellular device-to-device transceiver, a wireless local area link transceiver, and / or any other short-range transceiver such as other short-range wireless technologies. The apparatus 10, particularly the short-range transceiver, may be capable of transmitting data to and / or receiving data from an electronic device in the vicinity of the apparatus, for example, within about 10 meters. Also, the apparatus 10 including a Wi-Fi or wireless local area network modem may be capable of transmitting data to and / or receiving data from an electronic device according to various wireless networking technologies such as 6LoWpan, Wi-Fi, Wi-Fi low power, IEEE 802.11 technology, IEEE 802.15 technology, IEEE 802.16 technology, etc. WLAN technologies, and / or the like.

[0054] The device 10 may include a memory that can store information elements related to mobile subscribers, such as a subscriber identification information module (SIM) 38, a removable user identification information module (R-UIM), an eUICC, a UICC, and / or the like. In addition to the SIM, the device 10 may include other removable memory and / or fixed memory. The device 10 may include a volatile memory 40 and / or a non-volatile memory 42. For example, the volatile memory 40 may include a random access memory (RAM) including dynamic RAM and / or static RAM, on-chip or off-chip cache memory, and / or the like. The non-volatile memory 42 (which may be embedded and / or removable) may include, for example, read-only memory, flash memory, magnetic storage devices (such as hard disks, floppy disk drives, magnetic tapes, optical disk drives and / or media), non-volatile random access memory (NVRAM), and / or the like. Similar to the volatile memory 40, the non-volatile memory 42 may include a cache area for temporary storage of data. At least a portion of the volatile memory and / or the non-volatile memory may be embedded in the processor 20. The memory may be configured to store one or more software programs, instructions, information, data, and / or the like that the device can use to perform the operations disclosed herein with respect to the UE.

[0055] The memory may include an identifier such as an International Mobile Equipment Identity (IMEI) code that can uniquely identify the device 10. The memory may include an identifier such as an International Mobile Equipment Identity (IMEI) code that can uniquely identify the device 10. In an exemplary embodiment, the processor 20 may be configured to provide the operations disclosed herein with respect to the UE by using the computer code stored in the memory 40 and / or 42.

[0056] Some of the embodiments disclosed herein may be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware may be present, for example, on a memory 40, a control device 20, or an electronic component. In some exemplary embodiments, the application logic, software, or instruction set is held on any one of a variety of conventional computer-readable media. In the context of this specification, a "computer-readable medium" may be any non-transitory medium capable of containing, storing, communicating, propagating, or transporting instructions for use by or in connection with an instruction execution system, apparatus, or device such as a computer or a data processor circuit. In the example shown in FIG. 4, the computer-readable medium may include a non-transitory computer-readable storage medium that may be any medium capable of containing or storing instructions for use by or in connection with an instruction execution system, apparatus, or device such as a computer.

[0057] In some embodiments, the apparatus may include a user equipment configured to perform initial network access by receiving information indicating network support for initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme and transmitting at least a connection request based on the π / 2-BPSK modulation and coding scheme in response to the received system information, or the user equipment may be included therein.

[0058] Without limiting in any way the scope, interpretation, or use of the claims set forth below, one or more of the technical effects of the exemplary embodiments disclosed herein may include enhancement of the UE's initial network access.

[0059] The subject matter described in this specification may be embodied in a system, apparatus, method, and / or article according to a desired configuration. For example, the base stations and user equipment (or one or more components thereof) and / or processes described herein may be implemented by using one or more of a processor that executes 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 embodiments may include embodiments in one or more computer programs that are executable and / or interpretable on a programmable system that includes at least one programmable processor (which may be dedicated or general purpose), coupled to receive data and instructions from, and to transmit data and instructions to, a storage system, at least one input device, and at least one output device. These computer programs (also known as programs, software, software applications, applications, components, program code, or code) include machine instructions for a programmable processor and may be implemented in a high-level procedural and / or object-oriented programming language and / or in assembly / machine language. As used herein, the term "computer-readable medium" represents any computer program product, machine-readable medium, computer-readable storage medium, device, and / or equipment (e.g., magnetic disks, optical disks, memory, programmable logic device (PLD)) used to provide machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions. Similarly, a system that may include a processor and a memory coupled to the processor is also described herein. The memory may include one or more programs that cause the processor to execute one or more of the operations described herein.

[0060] Although several variations have been described in detail above, other improvements or additional examples are also possible. In particular, in addition to the description in this specification, other features and / or variations may be provided. Further, the above-described embodiments may be directed to various combinations and sub-combinations of the disclosed features and / or combinations and sub-combinations of multiple other features of the above disclosure. Other embodiments may also be included within the scope of the following claims.

[0061] If necessary, the various functions discussed herein can be executed in different orders and / or concurrently with each other. Further, if necessary, one or more of the above-described functions may be optional or may be combined. While various aspects of some embodiments are described in independent claims, other aspects of some embodiments include not only the explicit combinations in the claims, but also other combinations of the features of the described embodiments and / or dependent claims with the features of the independent claims. Also, it should be noted that although exemplary embodiments have been described herein, these descriptions should not be taken in any limiting sense. Rather, without departing from the scope of some embodiments as defined in the appended claims, multiple variations and improvements can be made. Other embodiments may also be included within the scope of the following claims. The term "based on" includes "based on at least". The use of the expression "such as" means "such as for example" unless otherwise specified.

Claims

1. receiving, at a user equipment, information indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; performing the initial network access by transmitting a connection request based on at least the π / 2-BPSK modulation and coding scheme in response to the received system information; The method includes:

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

3. The method according to claim 1 or 2, wherein the information is received from the network as a random access response comprising an uplink grant from a base station.

4. The method according to any one of claims 1 to 3, wherein the received information further indicates network support for a π / 2-BPSK demodulation reference signal.

5. The method according to any one of claims 1 to 4, wherein the connection request comprises a radio resource control connection request message transmitted over a physical uplink shared channel based on the π / 2-BPSK modulation and coding scheme and a demodulation reference signal.

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

7. 7. The method of claim 1, further comprising transmitting a Physical Random Access Channel (PRACH) preamble indicating user equipment support of the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal.

8. The method of any one of claims 1 to 7, wherein the received information further indicates one or more of: whether power boosting is used for performing random access channel access using the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal; whether power boosting is used for the initial network access or retransmission; whether power boosting is used for hybrid automatic repeat request retransmission; or one or more modulation and coding scheme indices suitable for π / 2-BPSK transmission.

9. transmitting information to the user equipment indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; receiving the initial network access including a connection request from the user equipment over a physical uplink shared channel; Detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme; The method includes:

10. 10. The method of claim 9, further comprising, in response to said detecting, responding to said connection request with connection setting information.

11. 11. The method of claim 9 or 10, wherein the information is transmitted as at least one of system information transmitted before a Physical Random Access Channel (PRACH) preamble is transmitted by the user equipment or a random access response including an uplink grant from the base station.

12. The method according to any one of claims 9 to 11, wherein the connection request comprises a radio resource control connection request message carried over a physical uplink shared channel by using the π / 2-BPSK modulation and coding scheme and a demodulation reference signal.

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

14. The method according to any one of claims 9 to 13, wherein the information indicative of network support further indicates support for the π / 2-BPSK demodulation reference signal.

15. 15. The method of any one of claims 9 to 14, further comprising receiving a Physical Random Access Channel (PRACH) preamble indicating user equipment support of the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal.

16. The method according to any one of claims 9 to 15, wherein the transmitted information further indicates one or more of: whether power boosting is used for performing random access channel access using the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal, whether power boosting is used for the initial network access or retransmission, whether power boosting is used for hybrid automatic repeat request retransmission, or one or more modulation and coding scheme indices suitable for π / 2-BPSK transmission.

17. The method according to any one of claims 10 to 16, wherein the detection further comprises detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme based on at least one of a demodulation reference signal sequence indicative of the π / 2-BPSK modulation and coding scheme or a cyclic redundancy check of the demodulation reference signal sequence.

18. 20. The method of claim 17, further comprising: transmitting to the user equipment, in response to the cyclic redundancy check failure, an allocation of an uplink grant including a downlink control information format of a retransmission using a new radio network temporary identifier for a π / 2-BPSK based retransmission.

19. An apparatus comprising: At least one processor; at least one memory containing computer program code, said at least one memory and said computer program code being executed by said at least one processor at least receiving information indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; performing the initial network access by transmitting a connection request based on at least the π / 2-BPSK modulation and coding scheme in response to the received system information; At least one memory configured to cause the apparatus to An apparatus comprising:

20. 20. The apparatus of claim 19, wherein the information is received as system information transmitted before a Physical Random Access Channel (PRACH) preamble is transmitted by the user equipment.

21. The apparatus according to claim 19 or 20, wherein the information is received from the network as a random access response comprising an uplink grant from a base station.

22. The apparatus of any one of claims 19 to 21, wherein the received information further indicates network support for a π / 2-BPSK demodulation reference signal.

23. The apparatus according to any one of claims 19 to 22, wherein the connection request comprises a radio resource control connection request message transmitted over a physical uplink shared channel based on the π / 2-BPSK modulation and coding scheme and demodulation reference signal.

24. 24. The apparatus of claim 23, wherein the demodulation reference signal comprises a π / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal.

25. The apparatus of any one of claims 19 to 24, further configured to transmit a Physical Random Access Channel (PRACH) preamble indicating user equipment support of at least the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal.

26. 26. The apparatus of claim 19, wherein the received information further indicates one or more of: whether power boosting is used for performing random access channel access using the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal; whether power boosting is used for the initial network access or retransmission; whether power boosting is used for hybrid automatic repeat request retransmission; or one or more modulation and coding scheme indices suitable for π / 2-BPSK transmission.

27. An apparatus comprising: At least one processor; at least one memory containing computer program code, said at least one memory and said computer program code being executed by said at least one processor at least transmitting information to the user equipment indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; receiving the initial network access including a connection request from the user equipment over a physical uplink shared channel; Detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme; At least one memory configured to cause the apparatus to An apparatus comprising:

28. 30. The apparatus of claim 27, further comprising, in response to said detecting, responding to said connection request with at least connection setup information.

29. 29. The apparatus of claim 27 or 28, wherein the information is transmitted as at least one of system information transmitted before a Physical Random Access Channel (PRACH) preamble is transmitted by the user equipment or a random access response including an uplink grant from the base station.

30. The apparatus according to any one of claims 27 to 29, wherein the connection request comprises a radio resource control connection request message carried over a physical uplink shared channel by using the π / 2-BPSK modulation and coding scheme and a demodulation reference signal.

31. 31. The apparatus of claim 30, wherein the demodulation reference signal comprises a π / 2-BPSK demodulation reference signal or a Zadoff-Chu DMRS demodulation reference signal sequence.

32. The apparatus of any one of claims 27 to 31, wherein the information indicative of network support further indicates support for the π / 2-BPSK demodulation reference signal.

33. 33. The apparatus of any one of claims 27 to 32, further configured to receive a Physical Random Access Channel (PRACH) preamble indicating user equipment support of at least the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal.

34. The apparatus of any one of claims 27 to 33, wherein the transmitted information further indicates one or more of: whether power boosting is used for performing random access channel access using the π / 2-BPSK modulation and coding scheme and / or the π / 2-BPSK demodulation reference signal, whether power boosting is used for the initial network access or retransmission, whether power boosting is used for hybrid automatic repeat request retransmission, or one or more modulation and coding scheme indices suitable for π / 2-BPSK transmission.

35. 29. The apparatus of claim 27 or 28, wherein the detecting further comprises detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme based on at least one of a demodulation reference signal sequence indicative of the π / 2-BPSK modulation and coding scheme or a cyclic redundancy check of the demodulation reference signal sequence.

36. 26. The apparatus of claim 25, wherein in response to the cyclic redundancy check failure, the apparatus transmits to the user equipment an allocation of an uplink grant including a downlink control information format of a retransmission using a new radio network temporary identifier for a π / 2-BPSK based retransmission.

37. means for receiving information indicative of network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; means for performing the initial network access by transmitting a connection request based on at least the π / 2-BPSK modulation and coding scheme in response to the received system information; An apparatus comprising:

38. Apparatus according to claim 37, further comprising means for performing any of the functions according to claims 2 to 8.

39. means for transmitting information to a user equipment indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; means for receiving the initial network access including a connection request from the user equipment over a physical uplink shared channel; means for detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme; An apparatus comprising:

40. Apparatus according to claim 29, further comprising means for performing any of the functions according to claims 10 to 18.

41. When executed by at least one processor, receiving information indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; performing the initial network access by transmitting a connection request based on at least the π / 2-BPSK modulation and coding scheme in response to the received system information; A non-transitory computer readable storage medium comprising computer program code for causing operations including:

42. When executed by at least one processor, transmitting information to the user equipment indicating network support of initial network access based on a π / 2 binary phase shift keying (π / 2-BPSK) modulation and coding scheme; receiving the initial network access including a connection request from the user equipment over a physical uplink shared channel; Detecting that the connection request was transmitted using the π / 2-BPSK modulation and coding scheme; A non-transitory computer readable storage medium comprising computer program code for causing operations including:

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