Exemplary aspects are directed to a radar-based detection circuit or system with signal reception circuitry to receive reflection signals in response to radar signals transmitted towards objects. The system may include logic/computer circuitry and a multi-input multi-output (MIMO) virtual array to enhance resolution or remove ambiguities otherwise present in processed reflection signals. The MIMO array may include sparse linear arrays, each being associated with a unique antenna-element spacing from among a set of unique co-prime antenna-element spacings.