Patent ID: 7623594

Claim:
An SDARS receiver for use with at least two antennae, each of which receives a SAT 1 bitstream from a first satellite and a SAT 2 bitstream from a second satellite, the receiver including: a SAT 1 demodulator configured to switch between demodulating the SAT 1 bitstream from one of the antennae and demodulating the SAT 1 bitstream from the other of the antennae; a SAT 2 demodulator configured to switch between demodulating the SAT 2 bitstream from one of the antennae and demodulating the SAT 2 bitstream from the other of the antennae; and a processor coupled to the demodulators, the processor being configured to switch the demodulators according to an algorithm wherein if a currently demodulated SAT 1 bitstream from one of the antennae is QPSK unlocked, then the processor switches the SAT 1 demodulator to demodulate the SAT 1 bitstream from the other of the antennae, and if a currently demodulated SAT 2 bitstream from one of the antennae is QPSK unlocked, then the processor switches the SAT 2 demodulator to demodulate the SAT 2 bitstream from the other of the antennae; wherein the processor determines a C/N ratio for each of the currently demodulated bitstreams when neither of the currently demodulated bitstreams is OPSK unlocked and the processor determines a first average C/N ratio over time for each of the currently demodulated bitstreams, wherein the processor switches each of the demodulators to demodulate a bitstream from a different antenna if both of the first average C/N ratios exceed a predetermined threshold wherein the processor determines a second average C/N ratio over time for each of the bitstreams from the different antenna after switching the demodulators and wherein the processor compares the second average C/N ratio to the first average C/N ratio for the bitstreams corresponding to each of the demodulators, and again switches demodulation to a bitstream from a different antenna for any demodulator having an associated second average C/N ratio that is less than its associated first average C/N ratio.