Single carrier filtering system architecture for flexible frequency domain multiplexing uplink

In this paper we present a new multiple access architecture for the uplink in a multi-carrier communications system. We are motivated by the case where the transmitters are low-power, low-complexity devices in a machine-to-machine (M2M) transmission scenario, such as is the case for a widespread sensor network with terrestrial base station or device-to-device relay. Each user transmits using single carrier (SC) modulation on separate pre-arranged contiguous carriers. The receiver employs orthogonal frequency division multiple access (OFDMA) processing. No frequency domain to time domain conversion is required in the transmitters, yet the receiver has the advantage of frequency domain equalization as well as a mechanism to separate each of the users. We highlight the savings in complexity at the transmitter and investigate the peak to average power ratio of the time domain signal. We demonstrate through simulation that our multiple access architecture has similar performance to conventional OFDMA in typical use cases and will outperform OFDMA when the dynamic range of transmitted signals is limited, such as by low resolution digital to analog converters.