Vehicles are increasingly getting connected with 5G cellular connectivity, and are expected to be connected to 6G in the future. One of the key features of 5G and of 6G will be use of millimeter wave (mmW) bands. In this paper, we consider vehicles equipped with mmW connectivity. The mmW band requires beam tracking and management to achieve high data rate. This can be particularly challenging for vehicle mobility. We study how perception from cameras in a vehicle can be used to improve beam management for mmW in vehicles. We propose a reinforcement learning-based beam management technique to combine 3D maps generated from perception with current 5G beam management. Our results show that the perception can be used to significantly improve the tail of throughput. Additionally, our results show that perception can also be used to significantly reduce power needed for beam management.

Vehicles are increasingly getting connected with 5thGeneration (SG) cellular connectivity, and are expected to be connected to 6thGeneration (6G) in the future. One of the key challenges of enabling cellular connectivity in a vehicle is radio frequency (RF) cabling from the sharkfin antennas on the top of the vehicle to modem placed inside the vehicle. Such placement of antennas is needed to negate the impact of out-to-in (O2I) losses introduced by a car body. Cost of the cabling can particularly be a concern as cellular systems utilize higher bands. In this paper we study using optically transparent and transmissive meta-surface(s) on windows of a vehicle to eliminate/mitigate the O2I loss. This can eliminate need for RF cable. To do so, we determine the 3-dimensional O2I loss of a Volkswagen Atlas sports utility vehicle (SUV) through measurements in an anechoic chamber. Next, based on this measured O2I loss and the proposed theoretical link model for a transmissive meta-surface we perform link-level analysis of the in-car antenna system with meta-surfaces installed on various glass surfaces. We analyze actively controlled and fixed design meta-surfaces. Our results show that actively controlled meta-surfaces (controlled with full channel information) of desired dimension and placed on the driver and passenger side window can recover the O2I losses in almost all cases. We additionally show that an in-vehicle antenna with fixed design meta-surface (i.e., with fixed refraction angle) can negate the O2I loss to be within 3 dB 90% of the time.

Integrated sensing and communication (ISAC) is being discussed in 5G Release 19 and will likely be a critical component of 6G. In this paper we study ISAC for automotive applications. Specifically, we focus on adding sensing capability to a vehicle modem. Such additional capability will increase the value proposition of adding higher bands connectivity to vehicles. We perform a comprehensive study of challenges needed to enable automotive grade sensing in a vehicle modem, and propose solutions to those challenges. We show how cyclic prefix-orthogonal frequency division multiplexing (CP-OFDM), which is used for communication, can be combined with novel receive processing to meet (and even exceed) the automotive sensing requirements. Furthermore, we propose a two-stage resource allocation scheme to minimize the overhead needed for sensing. This simplifies the tradeoff between communication and sensing. We also perform system level simulations to quantify the impact of sensing interference on cellular communication. Finally, we carry out measurements to identify antenna placement that can be used for both communications and sensing. Then, we prototype our proposals to demonstrate automotive level sensing using CP-OFDM.

In this paper, we study the cooperation between a connected vehicle user equipment (UE) and a handset UE within the connected vehicle. Specifically, we investigate how a vehicle UE can assist the performance of a handset UE inside the vehicle. We propose to use the vehicle UE as an alternative link for the handset UE inside the vehicle, thus taking advantage of the vehicle UE's externally mounted antenna to eliminate vehicle penetration loss to the handset UE. We demonstrate dynamic switching between the vehicle UE link and the handset UE link is the simplest solution, and the solution achieving significant performance gain. A switching algorithm is designed to improve handset UE coverage when inside the vehicle, while placing no additional requirements on the cellular communication architecture or specifications. The performance of the switching algorithm is prototyped and verified through extensive test drives.

One of the key features of 5G is the NR V2X (vehicle to everything) sidelink that has been first standardized during Release 16. V2X is designed to operate in a distributed manner, enabling operation independent of wireless network coverage. This differs fundamentally from traditional cellular networks where resources are centrally managed by gNodeBs. For distributed operation, 3GPP has defined a set of pre-configuration parameters in the Radio Resource Control (RRC) specification which can be set by the network, or pre-provisioned in the UE for OOC operation. The standard does not assign values for the pre-configuration parameters, but rather defines value ranges to provide flexibility and accommodate a rich span of applications and environments. To enable efficient and inter-operable operation these parameters need to be set carefully. In this paper, we evaluate pre-configuration parameter selection for several key aspects of NR Release-16 sidelink operations. In particular, we focus on distance-based quality of service, congestion control and resource reservation. Our results suggest parameter values suitable for various V2X applications, traffic types and operating conditions.

We examine systems of fixed-channel reuse for base stations in an indoor infrared wireless communication system. The following techniques are compared: time-division multiple access (TDMA) using on-off keying (OOK) or pulse-position modulation (PPM); frequency-division multiple access (FDMA) using binary phase-shift keying (BPSK) or quadrature phase-shift keying (QPSK); code-division multiple access (CDMA) using OOK with direct-sequence spreading by m-sequences or optical orthogonal codes (OOCs). We define a parameter /spl gamma/, which equals the signal-to-noise ratio (SNR) for unit optical path gain and is proportional to the square of the transmitted average optical power. Using measured pathloss data, it is found that in a system using hexagonal cells and a reuse factor of three, for cell radii above 3 m, TDMA with OOK or 2-PPM, and CDMA using OOCs all require approximately the same /spl gamma/ to achieve a worst-case bit-error rate (BER) of 10/sup -9/ within a cell. Using TDMA with 4-PPM results in a 6-dB decrease in the required value of /spl gamma/. CDMA using m-sequences requires an increase in /spl gamma/ of 5 dB over TDMA using OOK, and FDMA with BPSK requires an increase of 12 dB. For a given reuse factor N in the noise-limited regime, the required value of /spl gamma/ decreases in inverse proportion to N/sup 2/ for TDMA schemes and inversely with N for FDMA and CDMA schemes. For cell radii below 3 m, cochannel interference dominates the systems using TDMA, FDMA, and CDMA with an OOC, resulting in an irreducible BER above 10/sup -9/ at cell radii below 1.5 m. Only CDMA with m-sequences does not develop an irreducible BER, making it the only choice for cell radii below 1.5 m.

We report an experimental nondirected optical link for short-range, indoor data transmission at 50 Mb/s. The system uses on-off keying (OOK) and achieves low bit-error rates (BERs) in the presence of intersymbol interference, background light noise, and shadowing, with a range of 2.9 m in a skylit room. The transmitter produces an eye-safe Lambertian pattern at 806 nm with an average power of 474 mW. The receiver utilizes a hemispherical concentrator with a hemispherical bandpass optical filter, a 1-cm/sup 2/ silicon p-i-n photodiode, and a high-impedance hybrid preamplifier to achieve a high signal-to-noise ratio (SNR). A high-pass filter is used to mitigate fluorescent light noise, with quantized feedback removing the resulting baseline wander. A decision-feedback equalizer provides resistance to intersymbol interference due to multipath. The system and its components are characterized, and compared to theory. We observe that decision-feedback equalization yields a reduction of multipath power penalties that is in good agreement with theory.

We report an experimental 50-Mb/s free-space infrared link for indoor wireless communication, which achieves low bit-error rates (BERs) in the presence of multipath distortion, shadowing, and ambient natural and artificial lighting. The eye-safe 805-nm transmitter, directed at the ceiling, emits an on-off-keyed signal having 475-mW average power. The receiver employs a 1-cm/sup 2/ Si p-i-n photodiode coupled to a high-index hemispherical concentrator, which is covered by an optical bandpass filter of 30-nm bandwidth. A decision-feedback equalizer mitigates the effect of multipath ISI. In the presence of bright skylight, the link achieves a range of 2.9 m at 10/sup -7/ BER.