Patent ID: 7623571

Claim:
A method of retrieving a desired user data symbol sequence from a received signal, the method comprising: receiving a channel modified version of a transmitted signal comprising a plurality of user data symbol sequences, each being encoded with a user specific known code and a pilot symbol; determining an equalization filter directly and in a deterministic way from the received signal whereby filter coefficients of the equalization filter are determined such that one version of the received signal after filtering by the equalization filter is as close as possible to a version of the pilot symbol, wherein the filter coefficients are directly computed by using an explicit equation; and applying the equalization filter on the received signal to thereby retrieve the transmitted signal, wherein the explicit equation is one of the following: w _ a j j = arg ⁢ min w a j j ⁢  w a j j ⁢ Y a j - x 0 j  2 , ⁢ g _ a j j = arg ⁢ min g a j j ⁢  g a j j ⁢ Y a j ⁢ C p j H - s p j  2 , ⁢ g _ a j j = arg ⁢ ⁢ min g a j j ⁢  g a j j ⁢ Y a j ⁡ ( C p j H ⁢ C p j ) - s p j ⁢ C p j  2 , ⁢ f _ a j j , s _ d j = arg ⁢ ⁢ min f a j j , s d j ⁢  f a j j ⁢ Y a j - s d j ⁢ C d j - s p j ⁢ C p j  2 , ⁢ f _ a , s _ d = arg ⁢ ⁢ min f a , s d ⁢  f a ⁢ Y a - s d ⁢ C d - s p ⁢ C p  2 , ⁢ f _ a = arg ⁢ ⁢ ⁢ min f a ⁢  f a ⁢ Y a ⁡ ( I BN - C d H ⁢ C d ) -- ⁢ s p ⁢ C p  2 , ⁢ g _ a = arg ⁢ ⁢ min g a ⁢  g a ⁢ Y a ⁢ C p H - s p  2 , ⁢ g _ a = arg ⁢ ⁢ min g a ⁢  g a ⁢ Y a ⁢ C p , k H - s p , k  2 , ⁢ g _ a = arg ⁢ ⁢ min g a ⁢  g a ⁢ Y p , a ⁢ C _ p , k H - s p , k  2 , ⁢ f _ a , s _ d = arg ⁢ ⁢ min f a , s d ⁢  f a ⁢ Y a - s d ⁢ C d - s p ⁢ C p  2 , or f _ a = arg ⁢ min f a ⁢ {  f a ⁢ Y p , a - s p ⁢ C _ p  2 +  f a ⁢ Y d , a ⁡ ( I DN - C _ d H ⁢ C _ d )  2 } , wherein j is a base station number, wherein w a j j , g a j j , ƒ a j j , ƒ a , g a are 1×(Q+1)M linear fully-trained chip-level equalizers, wherein Y a j , Y a are(Q+1)M×BN output matrices, wherein x o j is a row of every input matrix X a , wherein C p j H , C p j , are pilot composite matrices, wherein s p j , s p , S p,k are pilot symbol vectors, wherein C d j is a multi-user composite code matrix, wherein s d j is a multi-user data symbol vector, wherein C p , C p,k H are pilot code sequence matrices, wherein C d , C d H are user code sequence matrices, wherein Y p,a is part of output matrix Y a , wherein B is a block length, wherein M is a number of antennas, wherein N is a length of user specific codes, wherein Q is a temporal smoothing factor, wherein a denotes a delay, wherein d denotes a user, wherein p denotes a pilot, and wherein H denotes a Hadamard matrix.