Identifying a sequence of received signals

A receiver of signals transmitted via a channel of a wireless communications system, said receiver being arranged to identify a sequence of received signals as one of a number of known orthogonal sequences, wherein the receiver is further arranged to:

• receive said sequence of received signals serially over a given time interval;
• receive, in addition to said sequence of received signals, at least one known signal at a time instant in said given time interval;
• divide said sequence of received signals into a first part comprising signals received before said time instant and a second part comprising signals received after said time instant, wherein the signals in the first part are distorted by a phase shift having a first polarity, and the signals in the second part are distorted by a phase shift having a second polarity that is opposite that of the first polarity;
• calculate from said sequence of received signals a modified received sequence by replacing at least one of the received signals from one of said parts by their complex conjugate values;
• correlate the modified received sequence with each one of the number of known orthogonal sequences to obtain a correlation result for each of said known sequences;
• and
• identify the sequence of received signals as the known (orthogonal) sequence having the largest correlation result.

A computer readable nontransitory storage medium having stored thereon program code for performing a method when said program code is run on a computer, wherein the method is a method of identifying, by a receiver of signals transmitted via a channel of a wireless communications system, a sequence of received signals as one of a number of known orthogonal sequences, comprising the steps of:

• receiving said sequence of received signals serially over a given time interval;
• receiving, in addition to said sequence of received signals, at least one known signal at a time instant in said given time interval;
• dividing said sequence of received signals into a first part comprising signals received before said time instant and a second part comprising signals received after said time instant, wherein the signals in the first part are distorted by a phase shift having a first polarity, and the signals in the second part are distorted by a phase shift having a second polarity that is opposite that of the first polarity;
• calculating from said sequence of received signals a modified received sequence by replacing at least one of the received signals from one of said parts by their complex conjugate values;
• correlating the modified received sequence with each one of the number of known orthogonal sequences to obtain a correlation result for each of said known sequences;
• and
• identifying the sequence of received signals as the known orthogonal sequence having the largest correlation result.