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—Vehicle-to-vehicle (VTV) wireless communications have many envisioned applications in traffic safety and congestion avoidance, but the development of suitable communications systems and standards requires accurate models for the VTV propagation channel. In this paper, we present a new wideband multiple-input-multiple-output (MIMO) model for VTV channels(More)
The development of efficient vehicle-to-vehicle (V2V) communications systems requires an understanding of the underlying propagation channels. In this paper, we present results on pathloss, power-delay profiles (PDPs), and delay-Doppler spectra from a high speed measurement campaign on a highway in Lund, Sweden. Measurements were performed at a This work is(More)
Car-to-car and car-to-infrastructure (henceforth called C2X) communications are constantly gaining importance for road-safety and other applications. In order to design efficient C2X systems, an understanding of realistic C2X propagation channels is required, but currently, only few measurements have been published. This paper presents a description of an(More)
Iterative multiuser detection and time-variant channel estimation in a multi-carrier (MC) code division multiple access (CDMA) up-link requires high computational complexity. This is mainly due to the linear minimum mean square error (LMMSE) filters that are used for multiuser detection and time-variant channel estimation. Krylov subspace methods allow for(More)
— Vehicle-to-vehicle (VTV) communications are of interest for applications within traffic safety and congestion avoidance, but the development of suitable communications systems requires accurate models for VTV propagation channels. This paper presents a new wideband MIMO (multiple-input-multiple-output) channel model for VTV channels based on extensive(More)
We consider the uplink of a time-variant multiple-input-multiple-output (MIMO) multiuser (MU) multi-carrier (MC) code division multiple access (CDMA) system. The linear minimum mean square error (LMMSE) filters for channel estimation and multiuser detection at the receiver side require too high complexity to be implementable in a system operating in(More)
— The throughput of the High Speed Downlink Packet Access (HSDPA) subsystem of UMTS suffers significantly from multiple access interference in the wireless channel. A linear minimum mean square error (LMMSE) equalizer at the receiver achieves higher throughput than a conventional RAKE receiver, at the cost of higher complexity. We introduce an iterative(More)
We focus on sphere decoding for the uplink of a multi-carrier (MC) code division multiple access (CDMA) system based on orthogonal frequency division multiplexing (OFDM). The users move at vehicular speed, hence the multiple-input multiple-output (MIMO) channel from each user to the base-station is time-varying. The receiver at the base-station performs(More)
Iterative multiuser detection based on linear minimum mean square error (LMMSE) filtering in time-variant MIMO systems involves high computational complexity. Sphere decoding after an initial interference cancelation step allows for substantial complexity reduction if the sphere decoder exploits the reduced rank time-variant channel subspace. However , a(More)