Method and apparatus for parallel midamble cancellation
AssigneeInterDigital Technology Corporation
InventorsRyan Buchert, Tonino Nasuti, Chayil S. Timmerman
Life of this patent
Estimating the term…
Abstract
Method and apparatus for performing midamble cancellation to remove midamble interference from the convolution tail of data field 1 and the first W-1 chips of the midamble field which results from the delay spread of the multipath channel and for canceling the first W-1 chip midamble spread in the data field 2, which operations are performed substantially simultaneously. The received burst, typically a TDD burst, is stored, the midamble interference and the corresponding parts in the received burst is removed and the resulting burst is applied to a multi-user detector to obtain the symbol sequences.
Claims32
A method for parallel midamble cancellation in a TDD burst for canceling the effect of midamble interference from corresponding parts of the received burst, comprising:
- a) receiving and storing the received burst;
- b) determining a channel estimation from a midamble portion of a received burst;
- c) utilizing the channel estimation for obtaining channel responses in midamble shift numbers;
- d) utilizing the channel responses, midamble shift numbers and the received burst for canceling the effect of midamble interference on the received burst, which includes data parts, midamble, and the guard interval, whereby the midamble interference on a received burst comprised of a data field 1, a midamble and a data field 2, is cancelled from the data burst.
A method for parallel midamble cancellation, comprising:
- storing a burst including at least data parts and a midamble;
- constructing midamble interference on a convolution tail of a first one of the data parts protruding on to the midamble field responsive to channel responses and midamble shift numbers;
- constructing midamble interference on a first group of chips of a second part of the data field responsive to said midamble shift numbers and channel responses;
- subtracting the midamble interference from a first number of chips of the midamble field of the data burst to provide an intermediate result;
- and
- subtracting the midamble interference from a first given number of chips of the second part of the data field from the intermediate result to provide a midamble canceled data burst.
A method for midamble cancellation comprising:
- a) storing a midamble a multi-stage shift register having an input stage and an output stage;
- b) applying a value of each stage of the register to an associated multiplier, whereby each multiplier multiplies the midamble of its associated stage with a channel response;
- c) separating each multiplier output into a real part and an imaginary part;
- and
- d) separately storing the real and imaginary parts.
Apparatus for parallel midamble cancellation in a TDD burst for canceling the effect of midamble interference from corresponding parts of the received burst, comprising:
- means for receiving and storing the received burst;
- means for determining a channel estimation from a midamble portion of a received burst;
- means for utilizing the channel estimation for obtaining channel responses and midamble shift numbers;
- means responsive to the channel responses, midamble shift numbers and the received burst for canceling the effect of midamble interference on the received burst which includes data parts, midamble, an the guard interval, whereby the midamble interference on a received burst, comprised of a data field 1, a midamble and a data field 2, is cancelled from the data burst.
Apparatus for parallel midamble cancellation, comprising:
- means for storing a received burst including at least data parts and a midamble;
- means for constructing midamble interference on a convolution tail of a first one of the data parts protruding on to the midamble field responsive to channel responses and midamble shift numbers;
- means for constructing midamble interference on a first group of chips of a second part of the data field responsive to said midamble shift numbers and channel responses;
- means for subtracting the midamble interference from a first given number of chips of the midamble field of the data burst to provide an intermediate result;
- and
- means for subtracting the midamble interference from a first given number of chips of the second part of the data field from the intermediate result to provide a midamble canceled data burst.
Apparatus for midamble cancellation comprising:
- means for transferring a midamble into a multi-stage shift register;
- means for applying a value at each stage of the register to an associated multiplier, whereby each multiplier multiplies the midamble of its associated stage with a channel response;
- means for separating each multiplier output into a real part and an imaginary part;
- and
- means for separately storing the real and imaginary parts.
Apparatus for canceling midamble interference from a received data burst comprised of a first and second data fields and a multi-bit midamble, said apparatus comprising:
- a plurality of processing elements (PE);
- means for obtaining channel responses and a midamble from the data burst;
- means for selectively coupling the channel responses to each PE;
- means for successively coupling each bit of said midamble to each PE;
- each PE including means for combining each channel response with each midamble bit;
- first and second accumulators for accumulating the output of each PE for each channel response;
- and
- means for respectively removing each value in said accumulators from said first and second data fields.
Dependencies are inferred from the claim text.