Low latency block scaling for baseband signal compression

The data rate between remote radio head (RRH) and baseband unit (BBU) in the distributed base station architecture is steeply increasing due to the new technologies such as multiple input multiple output (MIMO), coordinated multi-point (CoMP), carrier aggregation (CA) and multiband support. Compression of baseband signal is an efficient way to reduce the data rates on the optical fiber link. Compression can be achieved by eliminating redundancy resides in typical base band I/Q signals. This paper proposes two block scaling schemes for I/Q baseband signal compression, which enables low latency transport of the signal between BBU and RRH. Low latency is mainly achieved by reduced header information, which enables the block to diminish. The evaluation results suggest that the proposed schemes are promising in that they minimize the error vector magnitude (EVM) degradation in the reduced size of blocks and guarantee low latency. Proposed schemes can be applied efficiently to noisy uplink as well as downlink due to the scaling in accordance with the effective bit width of the signal.