Non-orthogonal AltBOC modulation for BeiDou B2 signals

New three-level binary offset carrier (BOC) subcarriers are constructed, based on which the non-orthogonal alternative BOC (AltBOC) modulation and its unequal power generalised form are achieved. The new constant envelope modulations have achieved a lower hardware complexity, which provide a solution to dual-frequency multiplexing problem confronted by BeiDou B2 frequency band.