Codex Corporation

About: Codex Corporation is a based out in . It is known for research contribution in the topics: Signal & Network packet. The organization has 189 authors who have published 241 publications receiving 32205 citations.

Frame loss due to buffer overflows in fast packet networks

Abstract: An analytical method is derived to estimate the protocol data unit (PDU) frame loss probability as a function of buffer size when identical sources are multiplexed on a fast packet link. The generation of PDUs from each source is governed by an on-off source model, and upper and lower bounds on the frame loss probability are derived. The analysis takes into account the correlated nature of fast packet losses within a PDU due to buffer overflows. The required buffer size for a given frame loss probability is directly proportional to the expected PDU frame length, and the loss probability decreases exponentially with increasing buffer size. >

A flexible, numerically robust array processing algorithm and its relationship to the givens transformation

Abstract: The development of systolic array processors is very important for real-time adaptive array processing applications. In this paper a numerically robust algorithm, based on the modified Gram-Schmidt (MGS) method, is presented. The algorithm can be efficiently realized using a systolic architecture and is capable of handling both exponential and finite memory windows in order to cope with time-varying data. Finally, the relation of these algorithms to similar schemes based on the Given's transformation is investigated.

Voltage controlled oscillator with controlled load

Abstract: A voltage controlled oscillator (VCO) includes a voltage controlled load. The voltage controlled load supplies additional capacitive loading to the VCO, via a transmission gate, at low frequencies to decrease the frequency-gain factor of the VCO. Moreover, at high frequencies, the effect of the voltage controlled load is minimized by turning off the transmission gate thereby allowing the VCO to operate at maximum frequency for worst case speed conditions.

Fast initialization of data-driven Nyquist in-band echo cancellers

Abstract: A echo canceller fast training scheme for data-driven Nyquist in-band echo cancellers is presented. This scheme simultaneously estimates the desired near and far echo canceller coefficients by sending a special periodic training sequence and correlating a segment of the sequence with the real echo samples. The requirements and the generation of the training sequence are discussed. It is shown that the fast training method can also provide the parameters for the fast initialization of the phase roll compensator in the echo canceller, and thus complete the fast training of the entire echo canceller. Compared to the conventional LMS training and other training methods, this scheme provides accurate estimates of the echo canceller coefficients in a significantly reduced training time. >