Method to increase performance of secondary data in a heirarchial modulation scheme

In a satellite audio radio service system, a method for receiving transmitted data, the method comprising the steps of:

• receiving a primary data stream and a secondary data stream from both a first communication satellite and a second communication satellite, the primary data stream having a first data rate and the secondary data stream having a second data rate;
• determining the validity of said first and said second data streams;
• and
• hierarchically modulating the primary and the secondary data streams to form a combined data stream when the secondary data stream is determined to be an enhancement to the primary data stream, wherein the combined data stream has a third data rate greater than the first data rate.

In a digital data transmission system including a transmitter for transmitting signals, a terrestrial repeater comprising:

• a receiving unit for detecting a first transmit signal and a second transmit signal, the first transmit signal transmitted from a first communication satellite and produced when the transmitter modulates a primary and a secondary data on a first carrier wave associated with the first communication satellite, and the second transmit signal transmitted from a second communication satellite and produced when the transmitter modulates the primary and the secondary data on a second carrier wave associated with the second communication satellite, wherein said receiving unit comprises an antenna in communication with a tuner unit for receiving the first and the second transmit signals, wherein the primary and the secondary data are modulated on the first and the second carrier waves using a M-PSK modulating scheme, said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals including primary data comprising one of QPSK, D-QPSK, and pi/4 D-QPSK modulated data, and said receiving unit is adapted to receive the first and the second transmit signals, the first and the second transmit signals each including secondary data spread over multiple symbols;
• an encoder for re-encoding the primary and the secondary data on a third carrier wave to form a third transmit signal;
• and
• a re-transmitter for transmitting the third transmit signal to a receiver.

In a digital data transmission system including a transmitter for transmitting signals, a terrestrial repeater comprising:

• a receiving unit for detecting at least one of a first transmit signal and a second transmit signal, the first transmit signal transmitted from a first communication satellite and produced when the transmitter modulates a primary and a secondary data on a first carrier wave associated with the first communication satellite, and the second transmit signal transmitted from a second communication satellite and produced when the transmitter modulates the primary and the secondary data on a second carrier wave associated with the second communication satellite comprising OFDM modulated data;
• an encoder for re-encoding the primary and the secondary data on a third carrier wave to form a third transmit signal;
• and
• a re-transmitter for transmitting the third transmit signal to a receiver wherein said receiving unit is adapted to receive the third transmit signal, the third transmit signal comprising OFDM modulated signal is inserted.