Multichannel Immediate Multiple Access for Dedicated Short-Range Communications: IEEE 802.11p-Compatible Physical Layer

This paper describes two concepts for Multichannel Immediate Multiple Access (MIMA) radio architectures for Dedicated Short-Range Communications (DSRC). Based upon an orthogonal frequency-division multiplexing (OFDM) physical layer, MIMA allows receivers to listen to all seven channels allotted for DSRC in the 5.9 GHz band and allows transmitters to send messages in any subset of the seven DSRC channels. The multichannel accessibility of MIMA further provides higher data rate for various applications, such as In-Vehicle Infotainment. The MIMA architectures are also compatible with the IEEE 802.11p standard, that is, they can coexist with 802.11p transceivers. One MIMA concept can increase spectrum utilization by up to 21.4% beyond carrier aggregation alone by utilizing guard bands in between aggregated DSRC channels. Another MIMA concept is to separate synchronization from demodulation and decoding, allowing a receiver to operate synchronizers for multiple channels in parallel but demodulating and decoding only those channels that are active, and thereby significantly reduce the FPGA or digital chip resources in the receiver. A prototype of the MIMA architecture has been implemented using an advanced software defined radio (SDR) platform. Preliminary results from the prototypes demonstrate the multichannel accessibility of the physical layer.