Systems and methods for transmitting and receiving additional data over legacy satellite digital audio radio signals

摘要

Systems and methods for transmitting and receiving additional data, such as video data, over legacy satellite digital audio radio signals are provided. In exemplary embodiments, hierarchical modulation can be used to transmit secondary information over a legacy signal. For example, the Sirius Satellite Digital Audio Radio Service (“SDARS”) system may use a second layer of modulation to transmit video data on top of its regular audio signal. In order to support such future services within the original system design, sometimes referred to herein as a “legacy” system, additional information bandwidth can be acquired, for example, by using hierarchical modulation to overlay data for such new services on top of the legacy transmission. In such a system, for example, overlay data can be transmitted by applying a programmable angular offset to legacy QPSK symbols, for forming a new constellation similar to 8PSK.

主权项

1. A method of transmitting information over a satellite digital audio radio service (“SDARS”) system, comprising:
first modulating a digital legacy signal using a first digital modulation scheme to encode the legacy signal into a first data stream of symbols; second modulating each of the symbols in the first data stream using a second digital modulation scheme to encode at least one additional digital signal, wherein the second digital modulation scheme adds at least one additional bit to each symbol of the first data stream by changing a combination of amplitude and/or phase offsets of the symbol of the first data stream to obtain twice modulated symbols; transmitting the twice modulated symbols over a satellite channel, wherein each of the legacy signal and the at least one additional digital signal contain a different synchronization signal; receiving the twice modulated symbols at a receiver; detecting direction of the amplitude and/or phase offsets of the received twice modulated symbols; first demodulating the received twice modulated symbols to extract the digital legacy signal; and second demodulating the second modulation scheme using the detected direction of the amplitude and/or phase offsets to extract the at least one additional digital signal.