### Abstract

In this paper we describe and simulate an accurate Bit Error Rate (BER) estimator for a chip level Wiener equalizer and combined equalizer/interference canceller for employment with the CDMA MIMO High Speed Downlink Packet Access (HSDPA) feature of the Third Generation Partnership Project (3GPP). In the 2×2 MIMO system two data streams may be transmitted in the downlink to each user equipment (UE) using assigned multiple orthogonal CDMA codes of Spreading Factor 16. The two streams are mapped to the two transmit antennas via a 2×2 weight matrix. Since the two streams use the same set of CDMA codes, it results in some direct interference between the two data streams at the receiver. The signal constellations from the two data streams interfere with each other and this complicates the BER estimation process. Treating this interference as AWGN is not sufficient for accurate BER estimation. The modulation type and order needs to be taken into account. Furthermore, the modulation order of the two data streams may also be different, e.g., QPSK may be used for one stream while 16QAM is used for the other. In this paper we describe the HSDPA transmitter and antenna weight matrix parameter calculations, as well as a chip level equalizer structure for which the BER is to be estimated. The transmit antenna weight matrix calculations are based on Channel State Information (CSI) and can be used, along with adaptive modulation and coding to optimize transmission. In the receiver a chip level 2×2 matrix Wiener equalizer is first used to recover the two transmit antenna streams in a minimum mean square error sense. The equalizer is implemented using a generalized overlap-save filtering method using FFT processing. Following this, the transmitter processing is reversed to estimate the transmitted data. The BER estimator must take into account white noise at the receiver, the interference between codes from loss of orthogonality due to the multipath channel, self noise from different time shifts of the given user's code (also due to the multipath channel) and the crosstalk between the user's two data streams, which use the same CDMA codes. The BER estimator for both the basic Wiener filter receiver and the Wiener filter plus interference canceller will be analyzed and compared with simulated BER measurements.

Original language | English (US) |
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Title of host publication | 2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011 |

DOIs | |

State | Published - 2011 |

Event | 2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011 - Farmingdale, NY, United States Duration: May 6 2011 → May 6 2011 |

### Other

Other | 2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011 |
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Country | United States |

City | Farmingdale, NY |

Period | 5/6/11 → 5/6/11 |

### Fingerprint

### ASJC Scopus subject areas

- Computer Networks and Communications
- Computer Science Applications
- Control and Systems Engineering
- Communication

### Cite this

*2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011*[5784244] https://doi.org/10.1109/LISAT.2011.5784244

**BER estimation for MIMO HSDPA : Chip level Wiener equalizer and successive interference cancellation.** / Lee, Yongwoo; Voltz, Peter; Pietraski, Philip; Yang, Rui.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011.*, 5784244, 2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011, Farmingdale, NY, United States, 5/6/11. https://doi.org/10.1109/LISAT.2011.5784244

}

TY - GEN

T1 - BER estimation for MIMO HSDPA

T2 - Chip level Wiener equalizer and successive interference cancellation

AU - Lee, Yongwoo

AU - Voltz, Peter

AU - Pietraski, Philip

AU - Yang, Rui

PY - 2011

Y1 - 2011

N2 - In this paper we describe and simulate an accurate Bit Error Rate (BER) estimator for a chip level Wiener equalizer and combined equalizer/interference canceller for employment with the CDMA MIMO High Speed Downlink Packet Access (HSDPA) feature of the Third Generation Partnership Project (3GPP). In the 2×2 MIMO system two data streams may be transmitted in the downlink to each user equipment (UE) using assigned multiple orthogonal CDMA codes of Spreading Factor 16. The two streams are mapped to the two transmit antennas via a 2×2 weight matrix. Since the two streams use the same set of CDMA codes, it results in some direct interference between the two data streams at the receiver. The signal constellations from the two data streams interfere with each other and this complicates the BER estimation process. Treating this interference as AWGN is not sufficient for accurate BER estimation. The modulation type and order needs to be taken into account. Furthermore, the modulation order of the two data streams may also be different, e.g., QPSK may be used for one stream while 16QAM is used for the other. In this paper we describe the HSDPA transmitter and antenna weight matrix parameter calculations, as well as a chip level equalizer structure for which the BER is to be estimated. The transmit antenna weight matrix calculations are based on Channel State Information (CSI) and can be used, along with adaptive modulation and coding to optimize transmission. In the receiver a chip level 2×2 matrix Wiener equalizer is first used to recover the two transmit antenna streams in a minimum mean square error sense. The equalizer is implemented using a generalized overlap-save filtering method using FFT processing. Following this, the transmitter processing is reversed to estimate the transmitted data. The BER estimator must take into account white noise at the receiver, the interference between codes from loss of orthogonality due to the multipath channel, self noise from different time shifts of the given user's code (also due to the multipath channel) and the crosstalk between the user's two data streams, which use the same CDMA codes. The BER estimator for both the basic Wiener filter receiver and the Wiener filter plus interference canceller will be analyzed and compared with simulated BER measurements.

AB - In this paper we describe and simulate an accurate Bit Error Rate (BER) estimator for a chip level Wiener equalizer and combined equalizer/interference canceller for employment with the CDMA MIMO High Speed Downlink Packet Access (HSDPA) feature of the Third Generation Partnership Project (3GPP). In the 2×2 MIMO system two data streams may be transmitted in the downlink to each user equipment (UE) using assigned multiple orthogonal CDMA codes of Spreading Factor 16. The two streams are mapped to the two transmit antennas via a 2×2 weight matrix. Since the two streams use the same set of CDMA codes, it results in some direct interference between the two data streams at the receiver. The signal constellations from the two data streams interfere with each other and this complicates the BER estimation process. Treating this interference as AWGN is not sufficient for accurate BER estimation. The modulation type and order needs to be taken into account. Furthermore, the modulation order of the two data streams may also be different, e.g., QPSK may be used for one stream while 16QAM is used for the other. In this paper we describe the HSDPA transmitter and antenna weight matrix parameter calculations, as well as a chip level equalizer structure for which the BER is to be estimated. The transmit antenna weight matrix calculations are based on Channel State Information (CSI) and can be used, along with adaptive modulation and coding to optimize transmission. In the receiver a chip level 2×2 matrix Wiener equalizer is first used to recover the two transmit antenna streams in a minimum mean square error sense. The equalizer is implemented using a generalized overlap-save filtering method using FFT processing. Following this, the transmitter processing is reversed to estimate the transmitted data. The BER estimator must take into account white noise at the receiver, the interference between codes from loss of orthogonality due to the multipath channel, self noise from different time shifts of the given user's code (also due to the multipath channel) and the crosstalk between the user's two data streams, which use the same CDMA codes. The BER estimator for both the basic Wiener filter receiver and the Wiener filter plus interference canceller will be analyzed and compared with simulated BER measurements.

UR - http://www.scopus.com/inward/record.url?scp=79960753028&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79960753028&partnerID=8YFLogxK

U2 - 10.1109/LISAT.2011.5784244

DO - 10.1109/LISAT.2011.5784244

M3 - Conference contribution

SN - 9781424498772

BT - 2011 IEEE Long Island Systems, Applications and Technology Conference, LISAT 2011

ER -