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In Global Navigation Satellite Systems (GNSS) the structure of the signal predominately determines the system performance and wideband signals, in general, offer good performance. Consequently signal design and the receiver processing for wideband signals have attracted significant research attention in recent years. The L5/E5 frequency band has been exploited for such high performance wideband signals as a part of the process of GNSS modernisation. Due to their appealing performance, the wideband signals are likely to be used in applications that demand high ranging accuracy. The wideband Alternate Binary-Offset-Carrier (AltBOC) modulation is the most sophisticated among the GNSS signals. The receiver baseband signal processing has to overcome several challenges before maximising the benefits offered by AltBOC modulation in terms of computational complexity, resource utilisation, and power consumption. This dissertation proposes efficient acquisition, tracking and multipath mitigation techniques for the L5/E5 band signals, specifically the AltBOC(15,10). The signal detection probability and mean acquisition time performance of different acquisition strategies for AltBOC(15,10) are analysed and a new acquisition method is proposed to increase the detection probability, reduce the mean acquisition time, and reduce the computational resource requirement. A generalised tracking architecture is described and a hybrid tracking architecture which maximises the received signal energy, and hence the tracking performance is proposed. An innovative Sideband-Carrier-Phase-Combination (SCPC) method is proposed to reduce the pseudorange multipath to less than one metre. Results from simulation as well as real test signals are provided to verify the proposed algorithms. In addition, results from an FPGA-based implementation are provided to validate the complexity reduction and power consumption benefit claims of these new methods. Learning from the drawbacks of the AltBOC modulation as far as the reduction in algorithm simplicity is concerned, this dissertation proposes a new modulation scheme called Time-Multiplexed Offset-Carrier QPSK (TMOC-QPSK) that behaves exactly like an AltBOC, yet is “receiver friendly”. A generalisation of the TMOC-QPSK, referred to as Time-Multiplexed-Multi-Carrier (TMMC) modulation, is presented and its potential in dealing with radio frequency interference and frequency selective propagation delay distortion is discussed.