A method for transmitting position location signals from a plurality of transmitters, comprising: selecting a set of digital pseudorandom sequences, wherein a maximum magnitude of a cross-correlation function between any two digital pseudorandom sequences of the set of digital pseudorandom sequences is below a specified threshold; selecting, from the set of digital pseudorandom sequences, a subset of digital pseudorandom sequences, wherein all magnitudes of an autocorrelation function of each member of the subset of the digital pseudorandom sequences of the subset, within a specified region adjacent to a peak of the autocorrelation function, are equal to or less than a prescribed value; transmitting from each transmitter of the plurality of transmitters a respective positioning signal, wherein at least a first portion of each positioning signal is modulated in accordance with a member of the subset of digital pseudorandom sequences, wherein at least two transmitters of the plurality of transmitters phase modulate the first portion of respective positioning signals in accordance with different members of the subset of digital pseudorandom sequences, wherein said cross-correlation function and autocorrelation function are circular cross-correlation and autocorrelation functions, wherein the prescribed value is the peak of the autocorrelation function divided by the length of the digital pseudorandom sequences, and the selected digital pseudorandom sequences are pseudorandom sequences selected from one of Kasami codes, Bent codes, or Gold codes using quaternary coded modulation with two Kasami codes, Bent codes, or Gold codes in quadrature and whereby the cross correlations of the two codes are negligible in the vicinity of the -1 run of the two codes and the specified region adjacent to the peak of the autocorrelation function includes at least ten consecutive digital pseudorandom sequence symbols selecting a set of digital pseudorandom sequences, wherein a maximum magnitude of a cross-correlation function between any two digital pseudorandom sequences of the set of digital pseudorandom sequences is below a specified threshold; selecting, from the set of digital pseudorandom sequences, a subset of digital pseudorandom sequences, wherein all magnitudes of an autocorrelation function of each member of the subset of the digital pseudorandom sequences of the subset, within a specified region adjacent to a peak of the autocorrelation function, are equal to or less than a prescribed value; transmitting from each transmitter of the plurality of transmitters a respective positioning signal, wherein at least a first portion of each positioning signal is modulated in accordance with a member of the subset of digital pseudorandom sequences, wherein at least two transmitters of the plurality of transmitters phase modulate the first portion of respective positioning signals in accordance with different members of the subset of digital pseudorandom sequences, wherein said cross-correlation function and autocorrelation function are circular cross-correlation and autocorrelation functions, wherein the prescribed value is the peak of the autocorrelation function divided by the length of the digital pseudorandom sequences, and the selected digital pseudorandom sequences are pseudorandom sequences selected from one of Kasami codes, Bent codes, or Gold codes using quaternary coded modulation with two Kasami codes, Bent codes, or Gold codes in quadrature and whereby the cross correlations of the two codes are negligible in the vicinity of the -1 run of the two codes and the specified region adjacent to the peak of the autocorrelation function includes at least ten consecutive digital pseudorandom sequence symbols