公开(公告)号：US20180248577A1

公开(公告)日：2018-08-30

申请号：US15755255

申请日：2016-10-12

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Nhat NGUYEN ,  Yikui Jen DONG ,  Arash ZARGARAN-YAZD ,  Wendemagegnehu BEYENE

IPC: H04B1/12 ,  H04L25/03 ,  H04L27/06

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.

公开(公告)号：US20230253974A1

公开(公告)日：2023-08-10

申请号：US18092564

申请日：2023-01-03

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Kenneth C. DYER ,  Nhat NGUYEN ,  Shankar TANGIRALA

IPC: H03M1/00 ,  H04L25/03

CPC classification number: H03M1/002 ,  H04L25/03038 ,  H04L25/03 ,  H03M1/007 ,  H03M1/145

Abstract: A receiver includes a variable resolution analog-to-digital converter (ADC) and variable resolution processing logic/circuitry. The processing logic may use feed-forward equalization (FFE) techniques to process the outputs from the ADC. When receiving data from a channel having low attenuation, distortion, and/or noise, the ADC and processing logic may be configured to sample and process the received signal using fewer bits, and therefore less logic, than when configured to receiving data from a channel having a higher attenuation, distortion, and/or noise. Thus, the number of (valid) bits output by the ADC, and subsequently processed (e.g., for FFE equalization) can be reduced when a receiver of this type is coupled to a low loss channel. These reductions can reduce power consumption when compared to operating the receiver using the full (i.e., maximum) number of bits the ADC and processing logic is capable of processing.

公开(公告)号：US20210336627A1

公开(公告)日：2021-10-28

申请号：US17315699

申请日：2021-05-10

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Kenneth C. DYER ,  Nhat NGUYEN ,  Shankar TANGIRALA

IPC: H03M1/00 ,  H04L25/03

Abstract: A receiver includes a variable resolution analog-to-digital converter (ADC) and variable resolution processing logic/circuitry. The processing logic may use feed-forward equalization (FFE) techniques to process the outputs from the ADC. When receiving data from a channel having low attenuation, distortion, and/or noise, the ADC and processing logic may be configured to sample and process the received signal using fewer bits, and therefore less logic, than when configured to receiving data from a channel having a higher attenuation, distortion, and/or noise. Thus, the number of (valid) bits output by the ADC, and subsequently processed (e.g., for FFE equalization) can be reduced when a receiver of this type is coupled to a low loss channel. These reductions can reduce power consumption when compared to operating the receiver using the full (i.e., maximum) number of bits the ADC and processing logic is capable of processing.

公开(公告)号：US20200153468A1

公开(公告)日：2020-05-14

申请号：US16680859

申请日：2019-11-12

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Nhat NGUYEN ,  Yikui Jen DONG ,  Arash ZARGARAN-YAZD ,  Wendemagegnehu BEYENE

IPC: H04B1/12 ,  H04L27/06 ,  H04L25/49 ,  H04L25/03 ,  H04L25/02 ,  H04L27/00 ,  H04L27/01

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.

公开(公告)号：US20230353177A1

公开(公告)日：2023-11-02

申请号：US18144342

申请日：2023-05-08

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Nhat NGUYEN ,  Yikui Jen DONG ,  Arash ZARGARAN-YAZD ,  Wendemagegnehu BEYENE

IPC: H04B1/12 ,  H04L25/03 ,  H04L25/49 ,  H04L27/06 ,  H04L27/01 ,  H04L27/00 ,  H04L25/02

CPC classification number: H04B1/123 ,  H04L25/03057 ,  H04L25/4917 ,  H04L27/06 ,  H04L27/01 ,  H04B1/12 ,  H04L27/00 ,  H04L25/03133 ,  H04L25/0264 ,  H04L25/03076

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.

公开(公告)号：US20220149876A1

公开(公告)日：2022-05-12

申请号：US17527631

申请日：2021-11-16

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Nhat NGUYEN ,  Yikui Jen DONG ,  Arash ZARGARAN-YAZD ,  Wendemagegnehu BEYENE

IPC: H04B1/12

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.

公开(公告)号：US20210152205A1

公开(公告)日：2021-05-20

申请号：US17114782

申请日：2020-12-08

Applicant: Rambus Inc.

Inventor： Masum HOSSAIN ,  Nhat NGUYEN ,  Yikui Jen DONG ,  Arash ZARGARAN-YAZD ,  Wendemagegnehu BEYENE

IPC: H04B1/12 ,  H04L25/03 ,  H04L25/49 ,  H04L27/06 ,  H04L27/01 ,  H04L27/00 ,  H04L25/02

Abstract: Decision feedback equalization (DFE) is used to help reduce inter-symbol interference (ISI) from a data signal received via a band-limited (or otherwise non-ideal) channel. A first PAM-4 DFE architecture has low latency from the output of the samplers to the application of the first DFE tap feedback to the input signal. This is accomplished by not decoding the sampler outputs in order to generate the feedback signal for the first DFE tap. Rather, weighted versions of the raw sampler outputs are applied directly to the input signal without further analog or digital processing. Additional PAM-4 DFE architectures use the current symbol in addition to previous symbol(s) to determine the DFE feedback signal. Another architecture transmits PAM-4 signaling using non-uniform pre-emphasis. The non-uniform pre-emphasis allows a speculative DFE receiver to resolve the transmitted PAM-4 signals with fewer comparators/samplers.