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US 6,587,452 B1Granted
High performance signal structure with multiple modulation formats
AssigneesGolden Bridge Technology, Inc., Seiko Epson Corporation
InventorsSorin Davidovici, Emmanuel Kanterakis, Izumi Iida, Norio Hama, Nobuhiko Kenmochi
Life of this patent
Estimating the term…
Abstract
A mapping memory, for use with a transmitter, for mapping a first signal segment and a second signal segment of a packet so that each signal segment has the same average power level. Each signal segment is characterized by a different modulation format. The first signal segment might use BPSK, while the second signal segment might use QAM, having multiple amplitude levels.
Claims22
A packet transmitter or communicating data, comprising:
- a demultiplexer, coupled to a data input and having a plurality of outputs, for demultiplexing the data into a plurality of sub-data-sequence signals, with a respective sub-data-sequence signal at a respective output of said demultiplexer;
- chip-sequence means for outputting a plurality of chip-sequence signals, with each chip-sequence signal orthogonal to the other chip-sequence signals in said plurality of chip-sequence signals;
- a plurality of product devices, coupled to the plurality of outputs of said demultiplexer, respectively, and to said chip-sequence means, for multiplying each of the sub-data-sequence signals by a respective chip-sequence signal, thereby generating a plurality of spread-spectrum channels;
- a combiner, coupled to the plurality of product devices, for algebraically combining the plurality of spread-spectrum channels as a multichannel-spread-spectrum signal;
- a header device, coupled to said combiner, for concatenating a header for chip-sequence synchronization, to the multichannel-spread-spectrum signal, thereby generating a packet-spread-spectrum signal having a first signal segment and a second signal segment;
- a mapping memory, having an address port coupled to said combiner, and an input port for inputting mapping characteristics of the first signal segment of the packet-spread-spectrum signal and mapping characteristics of the second signal segment of the packet-spread-spectrum signal, said mapping memory, responsive to the first signal segment present at the address port, for mapping the first signal segment at a power level, said mapping memory, responsive to the second signal segment present at the address port, for mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the packet-spread-spectrum signal;
- and
- a transmitter subsystem, coupled to said mapping memory, for transmitting on a carrier frequency the packet-spread-spectrum signal using radio waves over a communications channel.
5 more elements
A packet transmitter for communicating data, comprising:
- demultiplexer means, coupled to a data input and having a plurality of outputs, for demultiplexing encoded data into a plurality of sub-data-sequence signals, with a respective sub-data-sequence signal at a respective output of said demultiplexer means;
- transmitter-spread-spectrum means, coupled to the plurality of outputs of said demultiplexer means, for spread-spectrum processing each of the sub-data-sequence signals by a respective chip-sequence signal, thereby generating a plurality of spread-spectrum channels, with the respective chip-sequence signal different from each chip-sequence signal in a plurality of chip-sequence signals for spread-spectrum processing the plurality of sub-data sequence signals, respectively, and with the plurality of chip-sequence signals commonly used by the transmitter-spread- spectrum means;
- combiner means, coupled to the transmitter-spread-spectrum means, for algebraically combining the plurality of spread-spectrum channels as a multichannel-spread-spectrum signal;
- header means, coupled to said combiner means, for adding a header for chip-sequence synchronization, to the multichannel-spread-spectrum signal, thereby generating a packet-spread-spectrum signal having a first signal segment and a second signal segment;
- mapping means, having an address port coupled to said header means, and an input port for inputting mapping characteristics of the first signal segment of the packet-spread-spectrum signal and mapping characteristics of the second signal segment of the packet-spread-spectrum signal, said mapping means, responsive to the first signal segment present at the address port, for mapping the first signal segment at a power level, said mapping means, responsive to the second signal segment present at the address port, for mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the packet-spread-spectrum signal;
- and
- transmitter-subsystem means, coupled to said mapping means, for transmitting at a carrier frequency the packet-spread-spectrum signal using radio waves over a communications channel.
4 more elements
A packet transmitter for communicating data, comprising:
- a demultiplexer, coupled to a transmitter-FIFO memory and having a plurality of outputs, for demultiplexing stored data into a first plurality of sub-data-sequence signals and a second plurality of sub-data-sequence signals, with a respective sub-data-sequence signal at a respective output of said demultiplexer;
- chip-sequence means for outputting a plurality of chip-sequence signals, with each chip-sequence signal orthogonal to the other chip-sequence signals in said plurality of chip-sequence signals;
- a first plurality of product devices, coupled to the plurality of outputs of said demultiplexer, respectively, and to said chip-sequence means, for multiplying each of the first plurality of sub-data-sequence signals by a chip-sequence signal of the plurality of chip-sequence signals, respectively, thereby generating a first plurality of spread-spectrum channels;
- a second plurality of product devices, coupled to the plurality of outputs of said demultiplexer, respectively, and to said chip-sequence means, for multiplying each of the second plurality of sub-data-sequence signals, by a chip-sequence signal of the plurality of chip-sequence signals, respectively, thereby generating a second plurality of spread-spectrum channels;
- a first combiner, coupled to the first plurality of product devices, for algebraically combining the first plurality of spread-spectrum channels as a first multichannel-spread-spectrum signal;
- a first header device, coupled to said first combiner, for concatenating a header for chip-sequence synchronization, to the first multichannel-spread-spectrum signal, thereby generating a first packet-spread-spectrum signal;
- a second combiner, coupled to the second plurality of product devices, for algebraically combining the second plurality of spread-spectrum channels as a second multichannel-spread-spectrum signal;
- a second header device, coupled to said second combiner, for concatenating a header for chip-sequence synchronization, to the second multichannel-spread-spectrum signal, thereby generating a second packet-spread-spectrum signal;
- a third combiner, coupled to said first and second header devices, for combining the first and second packet-spread-spectrum signals as a QAM packet-spread-spectrum signal having a first signal segment and a second signal segment;
- a mapping memory, having an address port coupled to said third combiner, and an input port for inputting mapping characteristics of the first signal segment of the QAM packet-spread-spectrum signal and mapping characteristics of the second signal segment of the QAM packet-spread-spectrum signal, said mapping memory, responsive to the first signal segment present at the address port, for mapping the first signal segment at a power level, said mapping memory, responsive to the second signal segment present at the address port, for mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the QAM packet-spread-spectrum signal;
- and
- a transmitter subsystem, coupled to said mapping memory, for transmitting the QAM packet-spread-spectrum signal on a carrier frequency using radio waves over a communications channel.
9 more elements
A packet transmitter for communicating data, comprising:
- demultiplexer means, coupled to transmitter-memory means and having a plurality of outputs, for demultiplexing stored data into a first plurality of sub-data-sequence signals and a second plurality of sub-data-sequence signals, with a respective sub-data-sequence signal at a respective output of said demultiplexer means;
- transmitter-spread-spectrum means, coupled to the plurality of outputs of said demultiplexer means, for spread-spectrum processing each of the first plurality of sub-data-sequence signals and each of the second plurality of sub-data-sequence signals by a chip-sequence signal of a plurality of chip-sequence signals, respectively, thereby generating a first plurality of spread-spectrum channels and a second plurality of spread-spectrum channels, with the respective chip-sequence signal different from each chip-sequence signal in the plurality of chip-sequence signals for spread-spectrum processing the first plurality of sub-data sequence signals, respectively, and with the plurality of chip-sequence signals commonly used by the transmitter-spread-spectrum means;
- first combiner means, coupled to said transmitter-spread-spectrum means, for algebraically combining the first plurality of spread-spectrum channels as a first multichannel-spread-spectrum signal and for algebraically combining the second plurality of spread-spectrum channels as a second multichannel-spread-spectrum signal;
- header means, coupled to said combiner means, for adding a first header, for chip-sequence synchronization, to the first multichannel-spread-spectrum signal, thereby generating a first packet-spread-spectrum signal, and for adding a second header, for chip-sequence synchronization, to the second multichannel-spread-spectrum signal, thereby generating a second packet-spread-spectrum signal;
- second combiner means, coupled to said header means for combining the first packet-spread-spectrum signal and the second packet-spread-spectrum signal as a quadrature amplitude modulated (QAM) packet-spread-spectrum signal having a first signal segment and a second signal segment;
- mapping means, having an address port coupled to said second combiner means, and an input port for inputting mapping characteristics of the first signal segment of the QAM packet-spread-spectrum signal and mapping characteristics of the second signal segment of the QAM packet-spread-spectrum signal, said mapping means, responsive to the first signal segment present at the address port, for mapping the first signal segment at a power level, said mapping means, responsive to the second signal segment present at the address port, for mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the QAM packet-spread-spectrum signal;
- and
- transmitter-subsystem means, coupled to said mapping means, for transmitting at a carrier frequency the QAM packet-spread-spectrum signal using radio waves over a communications channel.
5 more elements
A method for communicating data, comprising the steps of:
- demultiplexing the data into a plurality of sub-data-sequence signals;
- spread-spectrum processing each of the sub-data-sequence signals by a respective chip-sequence signal, thereby generating a plurality of spread-spectrum channels;
- combining the plurality of spread-spectrum channels as a multichannel-spread-spectrum signal;
- concatenating a header for chip-sequence synchronization, to the multichannel-spread-spectrum signal, thereby generating a packet-spread-spectrum signal having a first signal segment and a second signal segment;
- mapping the first signal segment at a power level;
- mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the packet-spread-spectrum signal;
- and
- transmitting on a carrier frequency the packet-spread-spectrum signal using radio waves over a communications channel.
5 more elements
A method for communicating data, comprising the steps of:
- demultiplexing stored data into a first plurality of sub-data-sequence signals and a second plurality of sub-data-sequence signals;
- spread-spectrum processing each of the first plurality of sub-data-sequence signals and each of the second plurality of sub-data-sequence signals by a chip-sequence signal of a plurality of chip-sequence signals, respectively, thereby generating a first plurality of spread-spectrum channels and a second plurality of spread-spectrum channels, with a respective chip-sequence signal different from each chip-sequence signal in the plurality of chip-sequence signals for spread-spectrum processing the first plurality of sub-data sequence signals, respectively;
- combining the first plurality of spread-spectrum channels as a first multichannel-spread-spectrum signal;
- combining the second plurality of spread-spectrum channels as a second multichannel-spread-spectrum signal;
- adding a first header, for chip-sequence synchronization, to the first multichannel-spread-spectrum signal, thereby generating a first packet-spread-spectrum signal;
- adding a second header, for chip-sequence synchronization, to the second multichannel-spread-spectrum signal, thereby generating a second packet-spread-spectrum signal;
- combining the first packet-spread-spectrum signal and the second packet-spread-spectrum signal as a quadrature amplitude modulated (QAM) packet-spread-spectrum signal having a first signal segment and a second signal segment;
- mapping the first signal segment at a power level;
- mapping the second signal segment at the power level, thereby maintaining a constant value of the power level for the second signal segment and the first signal segment of the QAM packet-spread-spectrum signal;
- and
- transmitting at a carrier frequency the QAM packet-spread-spectrum signal using radio waves over a communications channel.
8 more elements
Dependencies are inferred from the claim text.