Flexible rate split method for MIMO transmission
First Claim
1. A method for transmitting a digital packet comprising:
- encoding a plurality of N systematic bits across time into an encoded packet of size M bits;
determining a quality of at least a first channel from a feedback circuit;
dividing the encoded packet into a first transmission packet defining a first size M1 bits that includes N1 of the N systematic bits and a second transmission packet defining a second size M2 bits that includes N2 of the N systematic bits, wherein at least one of M1 and N1 is based on the determined quality of the first channel; and
transmitting in parallel the first transmission packet from a first antenna at a first rate over the first channel and the second transmission packet from a second antenna at a second rate over a second channel, wherein M, M1, M2, N, N1 and N2 are all non-zero integers except one of N1 and N2 may be zero, M is greater than N, M is at least equal to M1+M2, and N is at least equal to N1+N2.
1 Assignment
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Accused Products
Abstract
A method for transmitting a packet of N input bits includes encoding all of the N bits as a single entity, such as with an interleaver of length N within a turbo coder, outputting M encoded bits, channel interleaving the M bits, splitting the M encoded bits into a parallel first and second portion, and transmitting them over separate channels to achieve spatial diversity. The size of the first and second portion is determined based on a closed feedback loop that provides some knowledge of the channel, preferably a measure of channel capacity. The feedback loop may also provide channel knowledge to a subpacket selector associated with each transmit antenna, which determines an appropriate rate for that channel and selects subpackets to fill a transmission packet for that channel. The subpacket selectors choose a subpacket of systematic bits and fill the remaining transmission packet size with subpackets of parity bits. Eigenvectors may be employed to transmit each transmission packet over more than one channel with a power disparity between the channels. A transmitter according to the present invention is also described.
97 Citations
23 Claims
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1. A method for transmitting a digital packet comprising:
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encoding a plurality of N systematic bits across time into an encoded packet of size M bits;
determining a quality of at least a first channel from a feedback circuit;
dividing the encoded packet into a first transmission packet defining a first size M1 bits that includes N1 of the N systematic bits and a second transmission packet defining a second size M2 bits that includes N2 of the N systematic bits, wherein at least one of M1 and N1 is based on the determined quality of the first channel; and
transmitting in parallel the first transmission packet from a first antenna at a first rate over the first channel and the second transmission packet from a second antenna at a second rate over a second channel, wherein M, M1, M2, N, N1 and N2 are all non-zero integers except one of N1 and N2 may be zero, M is greater than N, M is at least equal to M1+M2, and N is at least equal to N1+N2. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A transmitter comprising:
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an encoder having an input for receiving a plurality of N systematic bits and an output for outputting a plurality of M bits, wherein M is greater than N;
a channel feedback circuit for determining a channel characteristic of a first communication channel;
a demultiplexer having an input coupled to an output of the encoder and an input coupled to an output of the channel feedback circuit, said demultiplexer for outputting in parallel a first portion M1 of the M bits at a first output and a second portion M2 of the M bits at a second output;
a first amplifier coupled to said first output for increasing a power of said first portion M1 of the M bits;
p1 a first antenna coupled to the first output for transmitting said first portion M1 of the M bits; and
a second antenna coupled to the second output for transmitting said second portion M2 of the M bits. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for transmitting a digital message comprising:
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encoding a plurality of input bits;
based on a determined characteristic of at least a first channel, adaptively splitting the encoded input bits into a first subpacket defining a first subpacket size and a second subpacket defining a second subpacket size; and
transmitting the first subpacket at a first rate over the first channel and the second subpacket at a second rate over a second channel.
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22. A transmitter comprising:
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an encoder to encode a plurality of input bits;
a demultiplexer, having an input coupled to an output of the encoder, to adaptively split the encoded plurality of bits into a first subpacket defining a first subpacket size and a second subpacket defining a second subpacket size;
a first antenna coupled to an output of the demultiplexer, to transmit the first subpacket at a first rate over a first channel; and
a second antenna coupled to an output of the demultiplexer, to transmit the second subpacket at a second rate over a second channel. - View Dependent Claims (23)
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Specification