DCT-based compression scheme for OFDM baseband signals

The requirements on the data rates of communication systems increase roughly an order of a magnitude at each new generation. This increase can be especially noticeable for the new centralized radio access networks (C-RAN) scenarios, considered for meeting the requirements of the fifth generation (5G) wireless systems. The general C-RAN architecture normally assumes data transmission in the form of digitized baseband, i.e. I/Q samples. This paper proposes a relatively low-complexity compression scheme for LTE OFDM baseband samples based on transform coding, using the discrete cosine transform (DCT). The compression method is evaluated in both downlink and uplink. The results show that this process can be configured to achieve compression ratio according with the load, for example, in the range of 5:1 to 31:1, with error vector magnitudes (EVMs) lower than 2.8%.